Inverter and PV System Technology

Inverter and PV System Technology

“Inverter and PV System Technology� takes a close look at the electrical components of the PV system and its interactions, gives an overview of market conditions and presents the latest technical developments. Corporate portraits of international companies round off this comprehensive industry guide on PV system technology.

Inverter and PV System Technology

www.pv-system-tech.com

Industry Guide 2012 Industry Guide 2012

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Inverter and PV System Technology 2012 · Industry Guide

Contents

Contents Foreword by K. H. Remmers, CEO Solarpraxis AG Industry

Companies

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5

Photovoltaic Plants and the Importance of Electrical Components . . . . . . . . . 8 Market Situation and Forecasts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 The PV Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Inverters and PV Plant Yield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Inverters and Grid Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Plant Monitoring and Identifying Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Island Grids and Parallel Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Protection against Lightning and Overvoltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Cables and Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Storage and Energy Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Inverter and PV System Technology

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Business Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Industry Guide 2012

ABB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Advanced Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 AEG Power Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Answer Drives Srl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Bonfiglioli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Shanghai Chint Power Systems Co., Ltd. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Danfoss Solar Inverters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 DEHN + SÖHNE GmbH + Co. KG. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Diehl AKO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Emerson Solar Europe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Enphase Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Fronius Deutschland GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Kaco new energy GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 meteocontrol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 KOSTAL Industrie Elektrik GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 KOSTAL Solar Electric GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Multi-Contact AG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Phoenix Contact GmbH & Co. KG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 REFUsol GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Santon Switchgear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 RPS S.p.A. – AROS Solar Technology Divison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Schneider Electric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 SIEL S.p.A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Siemens AG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 skytron® energy GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 SMA Solar Technology AG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 SolarMax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Solutronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Steca Elektronik GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Sungrow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Woodward IDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Cover images Front Main image Lead-acid gel batteries (source: Tom Baerwald) Small images, f.l.t.r.

Roof-mounted installation with generator junction box (source: Tom Baerwald) Generator junction box: cabling (source: Tom Baerwald) Inverter (source: REFUsol GmbH)

Publishers

Solarpraxis AG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Sunbeam GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Important Notice, Picture Credits, Legal Information, Sources

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98

Back 31 MWp solar power plant in South France (source: Siemens AG)

3

Inverter and PV System Technology 2012 · Industry Guide

Contents

Contents Foreword by K. H. Remmers, CEO Solarpraxis AG

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5

Industry

Photovoltaic Plants and the Importance of Electrical Components . . . . . . . . . 8 Market Situation and Forecasts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 The PV Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Inverters and PV Plant Yield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Inverters and Grid Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Plant Monitoring and Identifying Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Island Grids and Parallel Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Protection against Lightning and Overvoltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Cables and Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Storage and Energy Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Companies

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Business Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 ABB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Advanced Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 AEG Power Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Answer Drives Srl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Bonfiglioli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Shanghai Chint Power Systems Co., Ltd. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Danfoss Solar Inverters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 DEHN + SÖHNE GmbH + Co. KG. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Diehl AKO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 Emerson Solar Europe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Enphase Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Fronius Deutschland GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Kaco new energy GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 meteocontrol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 KOSTAL Industrie Elektrik GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 KOSTAL Solar Electric GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Multi-Contact AG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Phoenix Contact GmbH & Co. KG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 REFUsol GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Santon Switchgear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 RPS S.p.A. – AROS Solar Technology Divison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Schneider Electric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 SIEL S.p.A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Siemens AG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 skytron® energy GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 SMA Solar Technology AG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 SolarMax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 Solutronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Steca Elektronik GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Sungrow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Woodward IDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Publishers

Solarpraxis AG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Sunbeam GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Important Notice, Picture Credits, Legal Information, Sources

...............

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Inverter and PV System Technology 2012 · Industry Guide

Foreword

Foreword Dear Readers, Since the previous edition of this brochure came out in April of last year, the photovoltaics market has once again undergone a complete transformation. Last year saw the majority of market players drop their solar module prices by up to 50%, turning all the industry’s predictions and key indicators on their head.

Karl-Heinz Remmers, CEO of Solarpraxis AG

Decentralized energy grids will develop more quickly and unstable grids could be stabilized by photovoltaics, processes made possible by systems technology. At the same time, however, the pressure on prices and the need for improvements is also increasing in this field. At the end of 2008, when solar modules still cost as much as 3.70 euros – even when bought in bulk – the price of inverters, connection The speed at which this change occurred boxes, diodes, plug connectors and cables means it is bound to take a while before bore hardly any significance. The reduced we know how the new price level affects module prices and resulting lower system global markets. One guaranteed outcome, costs mean that every cent per watt however, will be the emergence of sizepeak invested in the system now counts. able markets in the sunny regions of the Development efforts are no longer just world with just limited public start-up focused on the further enhancement and funding. The changes are having an equal- extension of technical possibilities and ly significant effect in less sunny regions applications, but also on costs. A rapidly such as in Germany, where solar power growing market opens opportunities generated from homeowners’ roofs has for ramping up production, even in the become cheaper than conventional power systems technology sector. from the public grid, lessening the need for market launch programs. PhotovolThis year’s “Inverter and PV System Techtaic energy is now also better value than nology” Industry Guide aims to reflect all many forms of bioenergy and large solar these developments, as well as providpower plants are already significantly ing helpful ideas, suggestions and apt undercutting offshore wind energy prices. product presentations. The two “Inverter This is even true in the rather cloudy reand PV System Technology” forums held gions of northern and eastern Germany! every year in both Europe and the USA are proof of the significance that Solarpraxis Introducing photovoltaic energy to India attributes to the topic. We would like to or the Middle East will afford these take this opportunity to thank all of our regions extremely low energy generation customers for their support in further costs – provided the lessons learned from promoting the development of integrated planning and installation elsewhere are systems. successfully transferred. This process will lead to continued rapid growth of the Kind regards, global photovoltaics market in the coming years, with drastically reduced dependency on public support programs.

Karl-Heinz Remmers

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Inverter and PV System Technology 2012 路 Industry Guide

Inhaltsangabe

The Industry

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Inverter and PV System Technology 2012 · Industry Guide

Photovoltaic Plants and the Importance of Electrical Components

Photovoltaic Plants and the Importance of Electrical Components Grid-connected PV systems are not only becoming cheaper and more efficient, they are also growing smarter. Inverters no longer function as mere system optimizers; as PV system intelligence centers they are also increasingly required to perform grid services. The power grid is undergoing fundamental change which will cause distributed power generation to gain in importance. As photovoltaics becomes more widespread, increases are also being seen in the proportion of solar power that cannot be immediately absorbed by the grid. As a result, on-site consumption and storage technologies are becoming ever more important. Stand-alone systems and grid back-up systems are also seeing something of an upsurge, particularly in countries where the power supply is poor.

Inverter cable connection

The six turnkey PV plants constructed in the department of Alpes-de-Haute-Provence in southern France have a total output of 31 MWp.

A photovoltaic plant (PV plant) that feeds all the power it generates into the grid essentially consists of the following components: • PV generator (solar modules) • Support structure (mounting frame) • Generator junction box (GJB) • Inverter • Monitoring system • Feed-in meter • Grid connection • DC and AC cabling

Careful planning of the installation is critical to achieving the optimum balance between components. When integrating these components into a single system, the different module types available (modules with crystalline silicon solar cells or modules based on the various thin film technologies) must be given just as much consideration as the functions and properties of the inverter – which are becoming ever more diverse.

Photovoltaic systems need to do more than simply feed energy into the grid if they are to make an adequate contribution to the power supply. Installations must also play a role in stabilizing the grids, for example by supplying reactive power, supporting grid frequency or keeping an installation on the grid when there are grid failures. This is why, as the systems’ intelligence centers, inverters are also increasingly required to perform grid services.

Inverters are crucial to the efficiency of a PV system (right: inverter production).

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Inverter and PV System Technology 2012 ¡ Industry Guide

Market Situation and Forecasts

PV system components (possible designs)

1.

8.

2.

3.

4.

5.

Market Situation and Forecasts Taking into account information on Germany for the fourth quarter of 2011, market research group IHS iSuppli estimates that the global PV market amounted to 26.5 GW in 2011, translating into growth of 48% yearover-year. PV installations picked up strongly in the fourth quarter of 2011, growing to a new record level.

Data published in early January 2012 indicates that there was an extraordinary year-end rally in Germany, with 3 GW installed in the month of December alone. In addition to Germany, Italy, the United States, and China primarily contributed to the surge in global PV installations.

3.

9.

1.

2.

1. PV generator (solar modules) 2. Solar module junction box 3. Solar cable connector 4. Generator junction box (GJB) 5. Inverter 6. Import/export meter 7. Grid supply 8. Monitoring solutions 9. Power optimizer

00123467

6.

Inverter production

7.

DC

From purely feeding – the maximum amount of – energy into the grid through providing grid services, the inverter must now also develop itself into an energy manager that assesses the different options available for utilizing the solar power and then identifies the most profitable solution in each situation.

Private power supply is becoming increasingly distributed. Ever more PV system operators are themselves consuming the power generated on their roofs. PV systems technology is set to develop further as a result of this. This will particularly affect inverters, as they guide the solar power either into the household network, a power storage system or the public grid, depending on supply and demand.

Storage systems offer an attractive option for storing surplus power temporarily and then feeding it into the household power network as needed. The market for storage systems is still too young, however, to

10

AC

foresee which technologies will secure a large foothold. A likely future scenario will involve a mixture of distributed, shortterm storage systems and large, seasonal storage systems that are capable of storing surplus energy for several months.

Off the grid The importance of photovoltaics is not only growing in regions equipped with public power supply networks. In areas where these networks are still lacking, but where sufficient insolation is available, PV installations are able to generate electricity relatively cheaply. This is because offgrid supply usually costs less here than establishing a connection with a far-distant grid. As a result, ever growing numbers of stand-alone systems are springing up in sparsely populated or technologically less developed regions in Asia and Africa. PV systems are also increasingly to be found in areas where public grids exist but are unreliable. Here they operate in parallel to the grid and support it when necessary.

960 Wp installation in Jalalabad, Afghanistan

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Inverter and PV System Technology 2012 · Industry Guide

Market Situation and Forecasts

PV inverter revenue forecast

PV installations (MW) Upside potential

According to preliminary data published

by GSE (the authority in charge of registering photovoltaic grid connections), cumulative installations in Italy exceeded In Germany, a sluggish start to 2011 was followed by extraordinarily strong figures 12 GW at the end of 2011.

Due to the overlap of various subsidy in the second half of the year. Preliminary schemes, the situation is still confusing, data published on January 6, 2012, by the however. The current subsidy scheme, German Federal Grid Agency indicate the Conto Energia 4 that started in June that 3 gigawatts (GW) were installed in December 2011 alone, which is the highest 2011, is intended to run until 2016. It should pave the way for grid parity and volume ever installed in a single month. a targeted 23 GW of cumulative installaThe total market amounted to 7.5 GW tions by 2016. It is estimated that annual in 2011. The year-end rally was driven by expenditure for incentives will be limited excellent returns on project investments, enabled as a result of historically low sys- to 6 –7 billion euros.

As a consequence of the unforeseen tem prices. In the fourth quarter of 2011, prices for commercial rooftop installations explosion of the market in 2011, Italy’s annual budget is almost fully exhausted. The dropped to around 1.50 euros per watt.

Prices for residential rooftop installations cap is likely to be reached during the first dropped to around 1.80 euros per watt. half of 2012.

IHS iSuppli expects the current subsidy scheme to be revised in early 2012 by means of a new governmental decree.

Drastic feed-in tariff (FIT) cuts and a differentiation of FITs by region are likely.

2009 2010

Y/Y growth in % (upside)

Inverter revenue

Source: iSuppli

2012*

2016*

CAGR 2015 VS. 2010 (%)

Germany

7,408

7,503

5,500

7,500

0%

Italy

3,577

6,900

2,500

4,563

4%

United States

915

2,551

3,646

7,116

41%

China

537

1,856

2,867

6,350

51%

17,856

26,522

23,266

61,343

23%

worldwide

Source: iSuppli

2011*

2012

2013

2014

2015

Y/Y growth (%)

Taking into account these multiple changes, iSuppli expects that about 23 GW will be installed in 2012. This forecast has upside potential of 6 GW in China, Italy, Germany and emerging markets, which could take total installations up to 29 GW this year.

Latest developments in Germany indicate that the quarterly installation pattern in 2012 may well be completely different from that in 2011. A strong first half of the year could be followed by a weaker second half.

Estimated PV installations in selected countries (MW) 2010

0

For the USA, the effects of discontinuing the 1603 cash grant will be minimal and only short term in nature as companies adjust investment approaches to accommodate for this. The net result is a slight downward revision of the 2011 USA forecast by 150 megawatts (MW) in order to account for delays in several utility-scale projects. The commercial sector will experience moderate growth of ≈20% annually from 2011 to 2013.

Installation fever continued throughout 2011 in China until the end of the year. In a bid to secure the FIT rate of 1.15 Yuan per kilowatt hour, many EPC contractors and installers are now rushing to finish projects which were approved in China before July 1, 2011. This will take the country’s installed PV capacity to a record high.

China’s mid-term plan will benefit midterm PV growth; the country is very likely to increase its PV installation target to 15 GW in its imminent and long-awaited “12th 5-Year Renewable Energy Plan”.

The Chinese PV manufacturing industry needs a market to consume the huge PV manufacturing capacity that already exists, however. China must therefore itself consume a certain amount of the modules produced. Chinese EPC contractors and investors have had things easy of late, as they have been able to simply transfer their cash burdens to suppliers.

This trend will continue in 2012.

Country

2011

2016

-40

Source: iSuppli Source: iSuppli

12,270

2012

2013

2014

4,885

5,085

7,185

8,114

2011

3,229

4,658

2010

2,871 1,787

2009

Micro inverters (MW) Total MLPM (MW)

1,245 908 2,153

2.5

466 489 955

2012

5.0

244 230 474

2011

0

7.5

81 91 172

2010

0

10.0

8 24 32

0

40

Global annual shipments (gigawatts)

0

80

2.1

12.5

-3

20

4.3

-15

5

2

4.4

120

19

40

4

5.8 4.8

23

10

5.2

20

60

6

200 160

7.2

13

80

149

100

8

20

120

15

National markets and global development

Global annual inverter revenue (€B)

140

8.6

Y/Y growth (%)

20

23,266

25

17,865

30

150 6,000

26,522

35

MLPM shipment forecast

10

160

Y/Y growth (%)

Global annual photovoltaic installations (megawatts)

2012: Upside potential

2015

2016

Optimizers (MW) Source: iSuppli

Supplier markets

MLPM solutions

Despite robust growth in PV end markets, suppliers in all branches of the value chain continued to suffer from eroding prices, disappearing margins, and declining revenues.

In the last quarter of 2011, the situation worsened further, primarily for the polysilicon industry. Within a period of weeks, polysilicon prices followed wafer, cell, and module prices by plummeting.

The polysilicon spot price dropped to around 30 U.S. dollars per kilogram in the course of the fourth quarter – a decrease of approximately 40% compared to the previous quarter.

With module channel inventory sold off towards the end of the year, module manufacturers were also only able to benefit partially from the surge in installation during the fourth quarter.

Module level power management technology – MPLM – (microinverters and optimizers) continued to spread within the PV market during 2011, though tumbling prices for solar modules and conventional inverters has slowed the pace of penetration. The 2011 MLPM market revenues amounted to 167 million U.S. dollars and we forecast that this will rise sharply to 1.8 billion U.S. dollars by 2016, despite abrupt slumps in prices. The residential and small commercial rooftop market continues to be the main sales market.

Microinverters are being most readily accepted in countries where the market and installation network is less wellestablished, such as the USA, Ontario Canada, the UK, Benelux and France.

Inverters Despite overall increasing demand for solar systems, revenues in the inverter industry dropped by 15% to 4.4 billion euros during 2011. The major cause of this drop was the erosion of average selling prices (ASP) per watt, which went down by an average of 14% while MW shipments varied by only 1%.

Revenues are predicted to drift down another 3% in 2012 as MW shipments improve by 5% and average ASP erosion slows to around 7%. Driven primarily by improved installation demand and more stable competitive dynamics, growth in annual revenue is expected to return to the 20% range by 2014.

Optimizers can be applied more broadly because they still use an inverter and their role is more that of a power booster, improving energy harvest. They now cost around 0.15 U.S. dollars per watt (0.13 U.S. dollars per watt by mid year) and are expected to drop to 0.08 U.S. dollars per watt by 2014. Optimizers initially entered the European – and to a lesser degree the North American – residential market.

Commercial applications have become more popular in recent months.

* estimated

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Inverter and PV System Technology 2012 · Industry Guide

The PV Generator

The PV Generator Electrically connected solar modules make up a PV generator, which generates electrical power dependent on insolation and temperature. The output of a solar generator is therefore not only determined by the efficiency of its modules, but also by how well those modules exploit the strength and spectrum of the insolation, and how they react to the module temperature.

The “Waldpolenz” solar power plant in Germany produces around 40 million kilowatt hours of green power a year.

Solar park in Drama (Greece): With a rated capacity of two megawatts (MW), it covers an area of 60,000 square meters.

The photovoltaic effect in solar cells can be used to generate power. Solar cells are made from a variety of different materials, with crystalline silicon being the most common. Thin-film cells made from cadmium telluride (CdTe) or copper indium/ gallium disulfide/diselenide (CI/GS/Se) also represent major technologies. Several solar cells are connected together to make up a module. The electrical properties of crystalline modules are markedly different from those of thin-film modules and must be taken into account in order to achieve the highest possible yield in a given location.

Installation of a central inverter

The bigger the area, the thinner the module Since modules made from crystalline silicon are generally more efficient than thin-film modules, they are used wherever space is at a premium, such as on the roofs of single-family homes. Module efficiency therefore solely affects the space requirements for the PV plant: In the case of crystalline solar modules, an area of around five to nine sqm is needed to achieve an output of one kilowatt peak (kWp), whereas for thin-film modules the area required for the same output is between ten and 20 sqm – depending on the technology used.

Cell material

14

Module efficiency

Surface area need for 1 kWp

Monocrystalline silicon

13–19%

5–8 m2

Polycrystalline silicon

11–15%

7–9 m2

Micromorphous tandem cell (a-Si/μc-Si)

8–10%

10–12 m2

10–12%

8–10 m2

Thin-film cadmium telluride (CdTe)

9–11%

9–11 m2

Amorphous silicon (a-Si)

5–8%

13–20 m2

Thin film copper-indium/gallium-sulfur/ diselenide (CI/GS/Se)

Cells made from different materials have different efficiencies. PV array surface area depends on the type of cell used.

On the one hand this means that the cost of support structures and installation is higher for thin-film solar modules, and that the modules themselves must therefore be somewhat cheaper in a turnkey system of the same price. On the other hand, the area required only has an indirect effect on the specific yield of a PV plant, which is indicated in kWh/kWp. To calculate the specific yield, the electricity output (in kWh) is related to the installed system capacity (in kWp) so that module efficiency becomes immaterial. All in all, the specific yield and costs of photovoltaic installations – and thus their profitability – are roughly the same whether crystalline silicon modules or thin-film modules are used.

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Inverter and PV System Technology 2012 · Industry Guide

The PV Generator

MPP output dependent on temperature 15

Bypass diode

Bypass diode

Relative change (%)

10 STC (Standard Test Conditions)

5

cell 1

0

cell 2

cell 20

cell 21

cell 22

-5 -10

PMPP aSi

PMPP Power maximum power point

PMPP CdTe

-15 -20

PMPP cSi

-5

5

15

25

35

45

55

65

The reduced output and possibility of damage to cells and modules caused by shading can be mitigated by the use of bypass diodes. The diode short circuits the affected area and allows the current to bypass it.

Temperature (°C)

Temperature coefficient of the output voltage in MPP (PMPP): As the temperature increases, the PV module output drops steadily. Crystalline modules (cSi) are far more severely affected by this than thin-film modules (aSi and CdTe).

The cost of land plays a secondary role when installing ground-mounted systems, as economies of scale come into play in such installations. In recent years, groundmounted systems have therefore often been built using thin-film solar modules, though the astonishingly sharp drop in prices for crystalline silicon modules has now caused the thin-film market share to diminish again. This is not only the case with ground-mounted installations but in all market segments.

Crystalline silicon solar cells are particularly responsive to long-wave solar radiation. In contrast, thin-film modules make better use of the short and medium-wave range of the solar spectrum. In cloudy conditions, the spectrum that hits the ground has a higher proportion of shortwave light, which is best exploited by amorphous thin-film modules. CdTe, CI/ GS/Se and microcrystalline thin-film modules, on the other hand, are best suited to absorbing medium wavelengths. In general, thin-film modules are ideal for sites which experience a high proportion of diffuse insolation due to frequent cloudy weather, or temporary or partial shading.

Furthermore, they offer advantages when

the orientation of the solar modules (for example on an East or West-facing roof) is not ideal.

Temperature coefficient

The temperature coefficient of output voltage is negative. This means that the module output and output voltage decrease Despite their lower efficiency, which is measured in laboratory simulations under at high temperatures (higher than the artificial sunlight with an intensity of 1,000 reference temperature T=25°C under STC) while they increase at low temperatures.

W/m2, at module temperatures of 25°C and with spectral irradiance at air mass The temperature coefficient of current is 1.5 (standard test conditions, STC), the both very small and positive, so currents electricity yield of thin-film modules can be will only alter to a very small degree as a comparatively high under certain condiresult of temperature fluctuations. tions. On the one hand this is linked to the temperature coefficient gradient, which is Here is an example with some typical markedly different to that of a crystalline values: Under STC, a given solar module module. On the other, the specific yield in with crystalline silicon solar cells has kWh/kWp is a variable which is not related a nominal output of 200 Wp and the to surface area, meaning that the lower temperature coefficient of output is efficiency of individual modules becomes –0.5%/Kelvin (K). This means that the irrelevant for comparison. output of this module would decrease by 5% for every temperature increase of 10 K. If this module were to reach a temperature of T=55°C, the output would drop by 15%, i.e. the 200 Wp module would “only” supply 170 Wp. Inversely, at a module temperature of T=5°C, its output would increase to 220 Wp. Thin-film modules are characterized by a lower temperature coefficient of output, typically –0.3%/K. This means that at a module temperature

of T=55°C, the solar module would only show a drop in output of 9%.

Insolation can heat PV modules to as much as 70°C. For this reason, they are installed so as to ensure that air can circulate to provide sufficient rear ventilation.

Where rear ventilation is not possible, for instance if the modules are integrated into the roof or façade of a thermally insulated building, thin-film modules are better suited as their output is less dramatically impaired by high temperatures.

Bypass diodes prevent overheating Since a single solar cell is only able to generate around 0.5 volts, a number of cells are connected in series to form a string.

This has the disadvantage of making the module extremely sensitive to partial shading because, if the shadow of say a chimney pot or an antenna is cast on a cell, the affected cell will turn from power generator into power consumer, becoming a weak link which restricts the power output of the entire string.

Shaded cells do not generate electricity, while the other, fully illuminated cells in the string remain completely active and

drive their power through the shaded cell, which converts that power into heat. In extreme cases, this leads to a “hot spot” being created in the cell, which can melt a hole in the cell material. A bypass diode, which bypasses the module string containing the shaded cell, is therefore used to steer the electricity past the passive cell.

Positioned in the module junction box, a bypass diode usually bypasses 20 to 24 cells. Modules consisting of 60 to 72 cells are therefore often equipped with three bypass diodes, while three such diodes are generally employed in modules with between 54 and 60 cells. As each diode bypasses one string, even slight shading leads to the output of all the series-connected cells within a module being lost.

It would therefore be ideal if each solar cell could be equipped with a bypass diode. Unfortunately, the junction box does not provide enough space for this. To get around the problem, several manufacturers have started to laminate “string bypass diodes” into their modules. This allows a greater number of diodes to be used than will fit in the junction box, and shading tolerance is noticeably increased as a result.

Overall, shading has the same effect as sharply reduced insolation: a decreased flow of current. This applies in principle to both crystalline and thin-film modules.

However, the latter benefit from the striplike arrangement of their solar cells, as it is relatively uncommon for long, narrow, thin-film solar cells to become completely shaded. The reduction in output of a thinfilm module is therefore usually proportionate to the shaded area.

Where losses are expected due to high operating temperatures or shading, thinfilm modules are often given preference over crystalline silicon models.

From left to right: Roof-mounted installation in Germany Assembly Ground-mounted installation in France

Generator junction box: maintenance and interior

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Inverter and PV System Technology 2012 · Industry Guide

Inverters and PV Plant Yield

Generator junction box 1.

2.

3.

4.

1. Blocking diodes 2. DC switch 3. Surge suppressor 4. String fuses

Inverters and PV Plant Yield Major discrepancies exist between power generation with PV modules and the requirements of the public grid. The job of the inverter is to connect the systems with each other and to feed the solar power into the grid with the highest possible efficiency. A PV installation’s yield is, therefore, just as heavily dependent on the reliability and efficiency of the inverter as on the orientation, interconnection and quality of the PV modules.

String inverters

Reflection losses

Aging processes

Generator junction box

In order for yield to be increased even further, reflection losses must also be taken into account. Modules with antireflection glass are already in use, but are relatively expensive. Reflection losses can, however, be virtually eliminated if the PV generators are equipped to track the sun’s movement on a dual axis, though this involves relatively high additional expense for the mechanical system. Such outlay is really only worthwhile if adequate additional yield can be achieved, i.e. if the PV system is installed at a site with a high proportion of direct insolation, preferably along the earth’s sunbelt. This applies similarly to concentrating sunlight with mirrors or optical lenses.

Since they contain no moving parts, normally solar modules age very slowly.

As long as their materials (glass, solar cells, plastics, aluminum) have been carefully selected, they are also sufficiently weather resistant. If a system is installed in such a way that corrosion cannot take hold, it can achieve a service life of 20 years or more. The assembly frame should be designed to ensure that there are no corners or niches where dirt, leaves and other deposits could collect, and standing water should also be avoided. Different metals may only be used together if it can be guaranteed that no electrochemical reaction will take place. This particularly applies to the screws and clamps in the support frame that holds the PV generator.

The modules are connected in series to form a string. The cumulative voltage of the individual modules gives the string voltage, which must be calibrated to the system voltage of the inverters. Strings of equal length are then connected in parallel to make up the PV generator, where the output power of the strings is cumulative. Multiple string cables from the PV generator are consolidated using Yadapters or joined in a generator junction box (GJB).

Yield can also be increased by active cooling. Here, cooling modules on their rear side produce warm water or warm air in addition to electricity. All in all, the advantages of this method are, however, too few for it to have become well-established.

The GJB is located close to the modules and connects several strings in parallel, meaning that only one positive and one negative cable – albeit with large cable cross-sections – must be laid from each junction box to the downstream inverter.

It can also perform additional safetyIn the early days of PV technology, the related functions, such as that of string transparent conductive oxide (TCO) coatfuse or overvoltage conductor. If thin-film ing, applied to the illuminated upper face modules are used which are not reverse of most thin-film modules to conduct current proof, blocking diodes must also current, was often damaged by corrosion. be employed. In addition, there are certain TCO corrosion is irreversible and leads components which may be positioned to severe output losses. Such damage in several different locations within the predominantly occurs in the event of high system. For example, the main DC switch voltages caused by earth leakage currents. could be a part of the GJB or could be Grounding the generator’s negative pole integrated into the inverter. can prevent TCO corrosion, though it also precludes the use of several inverter types.

Tracking module

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Inverters and PV Plant Yield

I-V curve of a crystalline silicon solar cell

European Efficiency

4

100% Short circuit current

MPP 2

0.8

0.4

1

η=91.8%

η=96.4%

η=94.8% η=85.9% Cell power output (W)

3 Cell current (A)

1.2

η=95.8% η=96.0%

48%

50%

20% The open circuit voltage (VOC) is around 0.5 V. At the maximum power point (MPP) of the curve, the voltage is about 80% of the open circuit voltage (VOC) and the current is about 95% of the short circuit current (ISC).

The inverter represents the link between the solar generator and the public power grid, and must therefore perform several tasks simultaneously. The most important of these are MPP tracking and converting the solar modules’ direct current into gridcompatible alternating current. Recently, it has also assumed new tasks in supporting the public grid (see also page 26ff): An inverter is a power converter which converts the direct current supplied by the PV generator into alternating current that has the same voltage and frequency as the grid. If required, this conversion can occur with a specified phase shift, in order to feed reactive power into the grid (e.g. in the event of grid failure) and lend it support. Thanks to state-of-the-art power electronics, converting direct current to alternating current now only incurs minimal losses. The term “grid-tie inverter” (GTI) is also used for the device, as it is specifically geared toward the requirements of the public grid.

In order to ensure that it always feeds in the maximum power output – dependent on the actual insolation and temperature conditions – the inverter automatically

0

Open circuit voltage

0

0.2

Cell voltage (V)

searches for the PV generator’s optimal operating point, or “maximum power point” (MPP). The MPP must be continuously tracked to achieve optimum yields.

The current and voltage of the PV generator fluctuate widely owing to changes in insolation and temperature, and thus lead to a varying current-voltage (I-V) curve with different MPPs. Modern inverters are designed to always locate the MPP with precision and to follow its movement immediately. Such rapid tracking of the MPP enables the maximum possible output of the PV generator to be utilized.

0.4

13%

0 0.55

European and Californian Efficiency As a result of converting the direct current, losses are incurred which can be relatively high within the partial load range of the inverter (0 to 20% of the rated power), but which are usually less than 5% at the rated output. Inverters usually achieve maximum efficiency at around half the rated output; some of them even reach over 98%.

The gradient of the efficiency curve is an important factor in inverter design, as they should be operated in the partial In addition to tracking the MPP and conload range for as few hours as possible verting direct current (DC) into alternating each year. The time curve of a PV generacurrent (AC), the inverter performs other tor’s output in a given location is crucial critical tasks: It plays a part in system here. Because the PV generator will only monitoring, and collects and stores inrarely supply its full rated output, it is esformation, such as operating data, that is pecially important to know the probability necessary to analyze the efficiency of the of different outputs occurring.

PV plant. It also displays error messages and sends them to a computer when required. Furthermore, it monitors the grid connection and checks if this has failed or been switched off. Of late, inverters have also become responsible for controlling fault ride-through and supplying reactive power to stabilize the grid.

3%

0%

6%

P5 P10

P20

10%10%

P30

The European Efficiency standard (valid for the type of irridiance level found in Central Europe) is a method which enables different inverters with different efficacy curves to be compared by taking into consideration the amount of time the inverter can be expected to operate at particular percentage loads/levels of solar insolation:

P50

P100

Dimensioning Where moderate solar radiation is prevalent, but full insolation only rare, an inverter which has a much lower rated output than that of the PV generator should be selected.

Undersizing the inverter in this way has the advantage that it will more frequently ηEUR = 0.03 η5% + 0.06 η10% + 0.13 η20% operate in a higher output range, and will + 0.1 η30% + 0.48 η50% + 0.2 η100% thus be more efficient. The disadvantage of this system design is that the inverter For regions with high solar radiation – will more rapidly become overloaded if approximately 1,200 kWh/m3 annual glob- the level of insolation is high. Owing to al irradiance upon a horizontal surface as the inherent output limitations, energy in South Europe – Californian Efficiency will effectively be wasted, as it is not posleads to more appropriate results. Accord- sible to use all the energy generated by ing to different conditions of radiation its the solar installation. formula is: The operator must therefore decide ηCEC = 0.04 η10% + 0.05 η20% + 0.12 η30% whether solar energy yield or economic + 0.21 η50% + 0.53 η75%+ 0.05 η100% gain should take precedence. Maximum profitability can also be achieved with slightly undersized inverters, though at times this may be overloaded and energy yield will be diminished as a result. This setup is, however, also less expensive, a saving which can compensate for yield losses in many cases.

The inverter in this example has a European Efficiency of 95.5%. The maximum efficiency is 96.4%, but it only operates at this level of efficiency when the inverter is operating at 50% of its nominal rating.

Owing to the poor efficiency curve in the partial load range, it was initially widespread practice to design AC inverter output to be up to 25% lower than the rated generator output under STC. However, in view of today’s much improved efficiency curves, it is now recommended that such stark subdimensioning be avoided. Moreover, the accuracy of weather data has also improved, and it has come to light that short radiation peaks occur more frequently than expected, meaning that the rated inverter capacity should not be “too small” compared to the rated capacity of the solar modules.

Working on the basis that a maximum 0.5% of the energy generated should be lost due to output limitations, it is now recommended that an inverter’s rated output should be no more than 10% lower than the STC rated output of the solar generator. Many renowned experts even argue that the practice of subdimensioning inverters should be abandoned completely. With regard to the inverter’s new task of supplying reactive power, the rated capacity of the solar generator and inverter should be roughly the same.

Debates surrounding economically viable system design are ongoing.

Central inverter (left: production)

Left: Inverter assembly Right: Carport in Tongeren (Belgium) with the PV system inverters on lefthand side of photo

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Inverters and PV Plant Yield

Central inverter

Module inverters

1.

1.

3.

1. PV generator 2. Generator junction box 3. DC switch 4. Inverter 5. Grid supply

2.

The PV array consists of several strings of series connected modules. The whole of the installation is served by a single central inverter.

Autonomous operation

DC AC

4.

5.

Such inverters contain a microprocessor to create the on and off signals for the The interconnections within a solar gener- electronic circuit breaker. This switching ator represent “classic physics”: Connectfrequency is much higher than the grid ing individual modules in series allows frequency. By rapidly chopping the direct the voltage to be increased – connecting current supplied by the PV modules, strings in parallel augments the current. signals are created which best simulate The inverter input voltage is determined sine function. During pulse pauses, the by the number of modules connected in current is temporarily stored in the input series to form a string, whereas the input capacitor. current is determined by the number of strings. In each case, the “window” Because the inverter is not controlled between the minimum and maximum in- by the grid, but works autonomously, it verter voltage must be taken into account, also would feed in power when the grid as must the maximum current carrying is switched off, for example in the event capacity. Inverters are connected directly of maintenance work. In order to avoid to the public power grid and generally endangering the grid operator’s electrifeed three-phase voltage into the low cians, the system is required to have a voltage grid. For smaller installations with protective circuit which automatically inverter capacities of up to 4.6 kilowatts disconnects the inverter from the public (kW) (or 4.6 kilovolt amperes [kVa] to be grid if its voltage or frequency deviates precise), single-phase feed-in is also posfrom the authorized limits. Two automatic sible. load break switches are used to ensure safety. A common design concept for this Thanks to their high efficiency and the automatic disconnection device (ADD) is excellent quality of power they deliver to the “Mains monitoring unit with allocated the grid, self-commutated inverters have switching devices connected in series” gained a strong foothold in the market.

(MSD – see page 26ff).

Transformers The use of transformers in inverters simplifies the conversion of alternating current to match the grid voltage level, but involves magnetic and ohmic losses, and increases the device’s weight.

Furthermore, far from operating silently, it draws attention to itself with a lowpitched humming noise. For this reason, high frequency transformers are often used instead of 50 Hertz (Hz) models.

They are smaller, lighter in weight and more efficient, but require more complex power electronics.

If the direct current supplied by the PV generator is greatly above the crest value of the grid voltage, the transformer becomes technically redundant. In addition, buck-boost converters can be employed to expand the input voltage range of an inverter and adjust it to suit different PV generators. Owing to their higher efficiency, transformerless inverters are now well-established on the market.

Since removing the transformer also entails the loss of galvanic isolation, a DC-sensitive fault protection switch needs to be included. A further disadvantage of transformerless inverters is a slight increase in electromagnetic radiation (electrosmog). These inverters should therefore be installed in a cool, dry place away from living rooms or bedrooms.

DC AC

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2.

Module inverters connect single modules or pairs of modules directly with the grid.

3.

Inverter concepts

the need for DC cabling. Though easy to install on the rear side of the module, the devices have relatively low efficiency and high specific costs. To date, these small inverters are only used in special applications, such as installations with an output of between three and five kilowatts designed for consumption at source.

While insolation is low, only the master is active, but as soon as its upper output Recent times have seen the construction limit is reached, as insolation increases, of ever larger PV plants. As the modules the first slave is switched in. The characused here are the same as those used in teristic curve of the master-slave unit is smaller installations, tens of thousands composed of the curves of the individual of them are required to build megawattinverters, and therefore displays higher range solar power plants. The fact that efficiency in the lower output range than photovoltaic generation involves so many a central inverter. To ensure that the small elements means that, depending on Alternatively, all module strings can be workload is distributed evenly among the power rating, several options are avail- connected to one sole inverter – a central the individual inverters, master and slave able for feeding into the grid. inverter. This requires that all modules be are rotated in a fixed cycle, which could exposed to the same insolation conditions be that each morning the inverter with Today, inverters come in so many differ(in particular: same orientation and pitch, the fewest operating hours starts as the ent sizes that, in principle, each module no temporary shading). Central inverters master. could be fitted with a customized inverter. have proven successful in both small and Such module inverters essentially enable large-scale PV installations. Today, parIn addition to module and central inveroptimum adjustment to the MPP of each ticularly in large-scale PV plants, a variant ters, string inverters provide a third individual module. The alternating current of the central inverter with three to four option, enabling the MPP of each string output of these “micro inverters” can be inverters in hierarchical order (master and to be tracked individually. This solution easily connected in parallel, eliminating slave) is used. is ideal where strings receive different degrees of shading throughout the day, causing individual strings to have different operation points. Here, the electricity is fed into the grid by several, independent Single string inverters string inverters. A further variant of the string inverter is the multistring inverter, which combines several MPP trackers in one device.

2.

DC AC 70 MWp installation in Meuro (Germany)

1. PV generator 2. Inverter 3. Grid supply

1. PV generator 2. DC switch 3. Inverter 4. Grid supply

3.

4.

Single-string inverters take a single string of seriesconnected modules. Each string has its own inverter.

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Inverter and PV System Technology 2012 · Industry Guide

Optimization using individual MPP controllers Given that each module in a string has its own MPP, controlling the MPP of a string is always a compromise which results in losses. Inverters with separate MPP controllers have recently been developed to get around this problem.

These “power optimizers” – sometimes also called power maximizers depending on the company – equip each module with its own MPP tracker, which is housed in the module junction box. Each module is therefore able to generate electricity at its optimum operating point – uninfluenced by the other modules to which it is

Inverters and PV Plant Yield

connected in series, and thus allowing the inverter to achieve a high level of efficiency. Opinions on the actual efficiency of the different systems are divided. Advocates argue that they are particularly useful if a PV generator’s strings are exposed to different levels of insolation in the course of a day. Then, for instance, temporary shading on individual modules no longer impairs the yield of the system as a whole.

An enhanced version of the power optimizer was recently launched onto the market as the module maximizer. This device not only tracks the MPP, it also records the output data of a module at any given moment and sends this to the central monitoring system. This allows drops

Performing an inverter load test

Close-up of inverters

in the performance of individual modules to be detected straight away. Moreover, the module maximizer allows operators to disconnect the DC output of individual modules from the central monitoring center if this becomes necessary for maintenance work or in the event of a fire.

Inverter lifespan

Specific inverter functions are performed by power optimizers and module maximizers, and are thus moved upstream within the module configuration. It remains to be seen whether these developments will actually become widespread, or whether they will remain a niche application.

Long-term experience suggests that an inverter will operate fault-free for ten to twelve years before extensive repairs or full replacement become necessary.

Regular servicing will extend the lifespan of the inverter, but will never enable it to match that of the PV generator.

Inverters are used in many different environments: both indoors and outdoors and in almost all climate zones. The most important factor limiting where an inverter may be installed is the maximum permissible temperature at rated power.

Where the operation of the inverter or the ambient temperature could cause this to

be exceeded (e.g. if the inverter is installed in an uninsulated roof structure), active cooling becomes necessary. However, the use of ventilators entails further risks, for example when inverters are installed in agricultural buildings. Here, if incorrectly installed, the ventilator can draw grain dust or ammonia vapors into the inverter, which can restrict ventilator operation or induce corrosion. In order to increase service life, particular attention must therefore be paid to ensuring that an inverter’s individual components cannot overheat.

In addition, they must be kept free from dust, damp and aggressive gases.

String inverters protected from solar radiation

Stand-alone inverters

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Ground-mounted installation in Senftenberg (Germany) with central inverter in the background

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Inverter and PV System Technology 2012 ¡ Industry Guide

Inverters and Grid Integration

Inverters and Grid Integration Integrating increasing amounts of solar energy into the public power supply puts various demands on PV plants. For example, special protective devices are required to prevent the risk of danger in the event of mains interference. The more PV plants feed into the public grid, the greater the demands placed on the grid services that they must perform. This is why inverters are incorporated into the grid management system.

Maintenance of a central inverter Inverters need to play a greater role in grid management.

Guidelines and standards regulate exactly how PV plants should be connected to the public grid, which gives rise to two highly important requirements. Firstly, when solar power is fed into the grid the power quality of the grid should not be reduced.

Secondly, personal safety must be ensured in the event of mains interference. Another requirement has also recently gained importance: PV plants should support the power grid and perform grid-related control functions.

High demands on grid feed-in

Disconnection devices

The further away the feeding point from large power plants, the greater the requirements that are placed on grid feed-in. As a general rule, when electricity is drawn from the grid, the grid voltage falls, and when power is fed in it increases.

Particularly when PV plants feed into rural grid structures or grid branch lines, this can cause an increase in voltage that exceeds the specified limits.

The grid operator stipulates that a protective device be used between the power generating plant and the grid, which can disconnect the plant from the grid when necessary. Its primary function is to ensure personal safety, because if the grid is shut down to carry out repair or maintenance work, power generating plants could continue to feed energy into the grid and put the safety of staff at risk.

The requirements for power in-feed are clearly defined: The grid requires sinusoidal alternating current with stable voltage and frequency, and the harmonic component limits are regulated in guidelines and standards. Modern inverters meet these power quality requirements, yet in some cases limits may be exceeded.

When a large amount of energy is consumed, the voltage in these weak grid spurs decreases, meaning that the act of feeding in decentralized solar power supply counteracts this decrease in voltage and, in turn, supports the grid. Increased consumption and increased feed-in do not, however, always occur at the same time, which means that measures need to be taken to inhibit excessive increases in voltage. A further consequence is that – particularly when grid feed-in is high and consumption is low in a particular area of the grid – the flow of current can reverse in the power grid, and not all grids are prepared for this yet.

With smaller PV plants, this task is performed by an automatic disconnection device (ADD) or a manual disconnection device to which the grid operator has permanent access. An ADD recognizes grid failures and cutoffs, as well as changes to voltage and frequency which exceed the authorized limits, and disconnects the PV plant from the grid.

Voltage and frequency stabilities are high in the fully-developed, close-meshed grid supplied by large thermal power stations, and solar power can usually also be injected without problems, even in large quantities.

String inverters

26

Until 2004, only the use of an MSD as an ADD was permitted in Germany. The MSD measures grid impedance and is able to recognize power failure and cutoff on the basis of impedance jumps. Since 2005, other grid monitoring methods have been authorized: These include evaluating the harmonic components, measuring the deviation of grid frequency and three-phase voltage monitoring.

A single-phase ADD is sufficient for PV plants with a feed-in capacity of up to 4.6 kVA, while a three-phase ADD is required for plants with a feed-in capacity from 4.6 to 40 kVA. Larger plants are usually equipped with manual disconnection devices, which can be used to disconnect the PV installation from the grid.

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Inverter and PV System Technology 2012 · Industry Guide

Inverters and Grid Integration

Structure of the German power grid

Ultra-high voltage 220/380 kV

Power stations

Heavy industry European power union

Regional power suppliers Wind farms

Transformer

High voltage 110 kV

Rail

Large industrial plants Construction of a solar installation on a commercial building

Grid operators prefer ADDs with threephase voltage monitoring, while the MSD is now only used for single-phase feed-in due to its method of measuring impedance and the associated measurement pulses which cause interference.

Static and dynamic support In Germany, large-scale PV plants which feed into the medium-voltage grid must provide certain grid services in accordance with the country’s Medium Voltage Directive (Mittelspannungsrichtlinie). In addition to a device facilitating power reduction, these include static and dynamic grid support. Control algorithms are therefore developed for inverters in order to control voltage and frequency fluctuations.

Adherence to the Medium Voltage Directive has been compulsory since January 1, 2009, although transitional periods apply.

Comparable provisions are contained in the Low Voltage Directive, which has been in force since January 1, 2012, meaning that even small and medium-scale PV installations are now also required to perform grid services.

Static grid support is required when grid voltage rises or falls slowly. Support is provided by supplying reactive power and limiting active power dependent on the frequency. Dynamic grid support is predominantly required when voltage dips occur in the upstream high-voltage grid. The PV plant should not then shut down immediately, but should remain on the grid for a time (fault ride through, FRT) and feed-in reactive current to support the grid voltage dynamically. Only when the grid ceases to function for several seconds is the PV plant shut down.

The “VDE Application Guide VDE-AR-N 4105” (Generators connected to the lowvoltage distribution network – technical requirements for the connection to and parallel operation with low-voltage distribution networks) is intended to contribute to avoiding frequency stability problems in the power grid. For example, it states that, in future, photovoltaic installations will not strictly need to be completely disconnected from the grid upon reaching an overfrequency of 50.2 Hz, but rather that there will be a smooth transitional zone between 50.2 Hz and 51.5 Hz, within which the installation may continue to feed in power at a reduced capacity. This new application guide also affects existing plants with outputs of over 10 kWp, which need to be upgraded accordingly.

4.6 MWp installation in Hassleben (Germany)

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Since July 1, 2011, static grid support will be prescribed by law in Germany. This applies to all inverters that feed into the medium and low voltage grids which have an output of 3.68 kVA or above (230 V ú 16 A).

The transitional period expired on January 1, 2012, so practically all PV plants that are connected to the grid will be required to perform this grid service. These increased requirements on systems technology – particularly inverters – contribute to stabilizing the power grid and bring with them the advantage that it will now be possible, even in weak grids, to install a far greater amount of PV capacity before expansion of the grid is required.

The low-voltage grid offers great potential for conserving and displacing power, which can be optimized by decentralized feed-in systems. Microgrids generating their own power, which are connected to one another by the public grid, can play a decisive role in this and can complement the grid integration of photovoltaic systems. On-site consumption can further stimulate decentralization.

Large-scale PV plants

Transformer

Medium voltage 10/20 kV Large factories and residential areas, hospitals, office buildings, shopping malls…

Medium-sized industrial plants

Cogeneration plants

Low voltage 230/400 V

Agriculture

Transformer

Small-scale PV plants

Small and medium-sized enterprises

Small towns, individual households

Ground-mounted installation in Senftenberg and roof-mounted installation on a listed building in Munich (Germany)

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Inverters and Grid Integration

Possible grid disturbances

0

0

Voltage 0 Time (s)

0.02

0.04 0 Time (s)

Some power supplies, such as those used in older computers but also in other recent appliances and compact fluorescent light bulbs, cause changes in sine waves.

Decentralization and consumption at source Using intelligent control engineering, a variable, virtual, large-scale power station could be developed in connection with decentralized feed-in systems and electricity consumers. As elements in this power plant, PV plants would contribute to reducing the purchase of electricity from the public grid. Moreover, PV plants could improve supply security through short-term island operation.

In future, inverters will take over more and more grid management tasks and provide energy services. In addition to stabilizing voltage and frequency, these include controlling the power factor and the targeted production of harmonic components to improve grid quality.

918 KWp installation in Coswig (Germany)

0.02

0.04 0 Time (s)

When “capacitive” power appliances are switched on, brief disturbances arise. Battery chargers are examples of capacitive loads. But these loads have to be very great indeed for the disturbances to have an impact.

For this reason, bidirectional network interfaces are required to enable the necessary communication and to link the large number of decentralized suppliers and consumers together in “smart grids”.

Due to the decentralized nature of solar power generation, it is obvious that users generating power should themselves consume as much of this as possible at source. This reduces grid feed-in and the need to transport power over great distances.

In an average household, 20–30% of energy is consumed at times when solar power is generated. Simple measures could be used to increase this proportion by a further ten percentage points, for example by logging consumption as well as generation using the automatic plant monitoring system, which will compare both graphically. Users could then better adapt their consumption to match generation and maximize their own consumption of the solar power.

0.2

0.4

A large power consumer can put such a great load on the grid that voltage drops. Inverters can only compensate for such disturbances if the devices can store electricity.

Roof-mounted installation on the California Institute of Technology in Pasadena (USA)

The inverter could be fitted out so that it automatically switches on individual household appliances (washing machines, dishwashers, dryers, etc.) as soon as enough solar power is generated. These appliances would be equipped with remote-controlled sockets and their performance data stored as profiles. The PV plant and the power network in the home would thus be unified, and electronic appliances would be supplied with either pure solar power or a mix of solar and grid power depending on insolation.

In Germany, the personal consumption of solar power by those who generate it has been encouraged since 2009 as part of the Renewable Energy Sources Act (EEG).

Only energy consumed concurrently with its production, i.e. the actual energy that is not fed into the grid but is directly consumed in close proximity to the PV plant, is considered to be for “on-site consumption”. It is not possible to balance out yield produced throughout the year with yearly consumption. In order to check concurrency, a production meter is required in addition to a reference meter and a feed-in meter. The actual consumption at source is calculated from the difference between production and feed-in.

If feed-in is single-phase but individual consumers have a three-phase connection, differences will arise which impact badly on the evaluations of own consumption. Three-phase feed-in is, therefore, an advantage.

The next step is to bring together energy consumption control and battery storage – either as a stationary battery bank or in mobile format in an electric vehicle.

Conventional batteries are only of limited suitability for this purpose because high storage losses and low efficiency lead to costs of 20 to 30 euro cents per kilowatt hour saved. These costs can be reduced by higher consumption of energy at source, improved load displacement and, above all, by increased conservation.

500 KW installation in Kittitas County, Washington (USA)

A view on the United States In the United States, transmission lines run from 138 to 765 kilovolts (kV) whereas distribution lines run as low as 4 kV. However, different voltage levels compared to European countries are not the main challenge for feeding solar power into the U.S. grid: it is the complexity of its structure.

The electric grid in the United States is a collection of many regional grids that are owned and operated by private companies but governed by state and federal governments. Figuring out interconnection and the wholesale power market rules can be daunting for new entrants into the solar market.

The country is roughly divided into three main power grids: Western Interconnect, Texas Interconnect and Eastern Interconnect (Hawaii and Alaska have their own grid). Each region is further divvied up by grid operators who coordinate and monitor these transmission networks and who sometimes also oversee the wholesale electric market. Ten large grid operators serve two-thirds of the consumers in the United States and more than 50% in Canada.

In California, the largest solar market in the nation, the California Independent System Operator manages about 80%of the grid. Utility-scale project developers typically apply to the California ISO for the right to connect their projects to the transmission network. The application involves hefty fees; sometimes developers have to help pay for new transmission equipment in order to send power from their projects in remote areas to cities. For commercial and residential PV customers, developers apply to their utilities for connecting their systems to the part of the grid that is called the distribution network. The United States has more than 3,200 public and private utilities.

The anticipated growth in solar and other renewable sources has prompted the Federal Energy Regulatory Commission, states, grid operators and utilities to examine whether they need to expand and upgrade the transmission networks.

More renewable power projects require a greater grid capacity. The intermittent nature of solar and wind makes it difficult for grid operators to predict and manage supply and demand.

Nellis Solar Power Plant in Clark County, Nevada (USA)

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Inverter and PV System Technology 2012 · Industry Guide

Plant Monitoring and Identifying Faults

Plant Monitoring and Identifying Faults Every kilowatt hour counts, because only kilowatt hours that are fed-into the grid or privately consumed are remunerated. It is therefore necessary to thoroughly monitor operational data. A plant’s operator can only take prompt measures to eliminate operational faults and failures where these are signaled immediately. Merely reading the feed-in meter each month is not sufficient to recognize faults promptly and to avoid the loss of yields. Constant measurements are therefore necessary to ensure optimal operation.

Transmission lines in the USA

Although the grid can accommodate the infusion of renewable energy in the near future, it is old and unequipped with the types of sensors and controls that will be necessary to modify the voltage and frequency – and to facilitate a greater amount of two-way flow of power from distributed systems – in order to keep the grid working properly. Transmission projects typically take years to plan, secure permits, line up financing and build.

In fact, a transmission project can take anywhere from five to 15 years to secure all the permits, according to Lauren Azar, a senior advisor to U.S. Energy Secretary Steven Chu. As a result, government regulators and utilities are anxious to figure out what they need to do to modernize the grid and get project development underway.

Last October, nine federal agencies announced the formation of the Rapid Response Team for Transmission to oversee seven pilot projects, which aim to show what the federal government can do to speed up the permitting processes. The agencies involved include the departments of energy, interior, agriculture, commerce and defense, as well as the Environmental Protection Agency and the Federal Energy Regulatory Commission. The interior and agriculture departments are part of the group because they manage public lands that could be used for transmission projects. The seven pilot projects are set to be built across twelve states: Arizona, Colorado, Idaho, Minnesota, New Mexico, Nevada, Wyoming, Utah, New Jersey, Pennsylvania, Oregon, and Wisconsin.

The west coast of the USA profits from favorable insolation conditions.

Here: the “Wild Horse Solar Power Project” in the state of Washington.

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Programming data loggers for PV power plants

Some other notable projects include an ambitious plan to build a hub of transmission lines to connect the three main power grids. It is planned to convert alternative current from the three power grids into direct current using a superconductor technology that should effectively connect AC grids that are not synchronized.

In February 2011, the U. S. Department of Energy (DOE) announced its first-ever loan guarantee for a transmission project called One Nevada Transmission. The DOE is providing a loan guarantee of U.S. dollars 343 million to NV Energy and Great Basin Transmission to build a 235-mile transmission line to connect the northern and southern service territory of NV Energy for the first time. The 500-kilovolt line, which will cost about U.S. dollars 500 million in total to build, will be able to ferry 600 megawatts of electricity and allow NV Energy to manage geothermal power from the north and solar power from the south. Project developers hope to complete the work in 2013.

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Inverter and PV System Technology 2012 · Industry Guide

Plant Monitoring and Identifying Faults

Creating a system for regulating power plants and grid security management

Many inverters record the most important operational data, evaluate the data automatically and, in the event of a fault, send the operator notifications via email, text message or internet. This is sufficient for basic plant monitoring. However, it only allows obvious faults, such as fault currents or total failure, to be recorded.

In order to determine whether a PV plant is producing optimal yields, the plant data needs to be measured continually, and preferably compared with the actual radiation values present. This is due to the fact that currents and voltages, and consequently feed-in capacities, constantly change depending on meteorological conditions. The operator can only determine whether or not the PV plant’s operational data indicate optimal functioning by directly comparing them with insolation data.

Installing a string inverter

34

Testing an inverter in a cold chamber

Measuring insolation and output Solar radiation is established either using pyranometers or PV sensors. A third – more indirect – possibility is to compare a plant’s data with meteorological data and yields from PV plants in that locality.

Pyranometers measure insolation on horizontal surfaces with great accuracy. They essentially consist of two hemispherical glass domes, a black metal plate that acts as an absorbing surface, the thermal elements positioned below this and a white metal casing. Solar radiation heats the absorbing surface, the warming of which is directly dependent on the insolation.

Insolation can thus be ascertained from the temperature difference between the absorbing surface and the white metal casing. The advantage of high measuring accuracy is, nevertheless, opposed by a serious disadvantage: Due to their thermal functionality, pyranometers are relatively sluggish, which means that they are incapable of accurately detecting rapid insolation fluctuations caused, for example, by broken overcast. Moreover, insolation recorded on a horizontal plane must be converted to the module plane in order to obtain meaningful radiation values for evaluating a PV plant’s yields.

PV sensors installed in the module plane offer a low-cost alternative to accurate, but slow and expensive, pyranometers: Here, there is no longer a need for the insolation measured to first be converted from horizontal to module plane. A PV sensor consists of a solar cell which supplies power in proportion to insolation.

This power is, however, also dependent on the operating temperature of the solar

cell, which means that a temperature sensor is necessary in order to offset thermal effects and determine the exact insolation. However, owing to its limited spectral response, the solar cell cannot detect certain portions of the insolation, and reflection losses may also occur. PV sensors are therefore much less accurate in their measurements of insolation than pyranometers. Despite this, they are often used to monitor PV plants. This is because a PV sensor can be selected to correspond to a plant’s modules. For example, a PV plant consisting of CI/GS/Se thin-film modules is monitored by a PV sensor with a CI/GS/Se solar cell. This simplifies the comparison of instantaneous values, which means that operational faults and defects can be recognized quickly.

With both pyranometers and PV sensors, additional measurement of the modules’ operating temperature is necessary to convert the insolation data to the target value. This is because, with the same insolation, a module supplies a much greater output on a cooler day than on a warm one.

Comparisons with regional meteorological data mean that pyranometers and PV sensors are no longer required. Yield simulations are calculated using data supplied by neighboring meteorological offices and compared with the actual yield. Operators can also check their own performance data by examining the yield of nearby PV plants. Both methods have the disadvantage that faults often go unrecognized for hours or even days.

Insolation data obtained from satellite pictures may also be consulted in order to determine whether the PV plant is running efficiently. The yields are recorded hourly and sent to a server via the internet once a day. There, the data are compared to the yields expected. This method achieves an average accuracy – although not very quickly – comparable to plant monitoring with PV sensors. If a fault is identified, it often cannot be rectified immediately because the target value and actual value of the yield are only compared once a day.

Another method of monitoring a plant is the continuous comparison of output supplied by the individual module strings (string monitoring). If all the strings have been installed with the same orientation, then their output should always be the same. If it is possible that partial shading could occur, this is known in advance.

Therefore, if a string unexpectedly falls behind the others this means that there must be a fault. String monitoring is a quick, simple and effective method of identifying yield losses.

If operational data are saved on the internet, a service provider (or “technical plant manager” in the case of large-scale installations) can assume the task of monitoring the plant and then inform the operators of any faults which occur, or even take independent measures to rectify them.

Causes of faults resulting in yield reduction Yield losses can generally be attributed to three causes of faults. Component faults, installation faults and faults caused by external influences.

Component faults are more frequently found in inverters than modules. These can be due to production faults, aging or thermal overload of the inverters. Such faults often lead to the complete failure of either the PV plant or the part of the generator connected to the defective inverters. An increasing number of inverter manufacturers are, therefore, now providing long-term guarantees and service contracts. PV modules are not as badly affected by thermal overload as inverters, but rather by external influences, although this happens over relatively long periods of time. Crystalline solar modules can supply power for 30 years without showing significant signs of aging.

ules or even whole strings will continue to fail as a result of electrical connections not being installed carefully enough.

Insulation can also be adversely affected by installation faults. For this reason, it is wise to use an automatic insulation monitor, which is integrated into some inverters.

External influences primarily affect PV modules. Over the decades, UV radiation from the sun will lead to light aging. The darkening of the plastic film (browning) can lead to a reduction in module output (degradation). Weather-induced aging is only observed relatively rarely in the plastics, in which the solar cells are embedded.

Cell damage occurs more often, which is caused by shading and subsequent excessive heating (hot spot). Bypass or string diodes may be damaged by thermal overload or overvoltages. Inverters are not normally directly exposed to meteorological conditions although they are adversely affected by circuit feedback, for example.

Manufacturing faults are often identified in the factory – provided the manufacturer has a good quality management system. So broken cells or incomplete lamination only rarely appear in a PV plant as component faults.

Installation faults rarely result in complete plant failure but only in partial yield reduction. Sometimes, installation faults only start to take effect after a certain time, which means that they are recognized far too late. If, for example, modules are installed so close to one another that there is no longer an expansion gap, the glazing may crack due to the effects of temperature and wind. Individual mod-

Monitoring data communication

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Inverter and PV System Technology 2012 · Industry Guide

Stand-Alone Power Systems and Grid-Parallel Operation

Hybrid system

Stand-Alone Power Systems and Grid-Parallel Operation Thanks to their simple, modular structure, PV installations are suitable for virtually all service environments the world over. In countries lacking local power grids, they form autonomous, stand-alone power systems that can be expanded as needed, and are thus a driving force in “rural electrification”. PV plants installed in areas where power grids exist but are unreliable are something of a specialty. They operate in parallel to the grid and then bridge periods when the power fails.

1. Factory 2. PV 1 (525 kWp) 3. PV 2 (225 kWp) 4. Battery charger 5. Battery (740 kAh) 6. Inverter 7. Island conditioning unit 8. Bio gas plant or diesel generator 9. Grid 10. Wind turbine 1.

8.

9.

6.

7.

Future extensions possible

2.

3.

10.

150 kWp 4.

5.

2.5 Wp stand-alone system in Pessene (Mozambique) to power lighting, the radio transmission system and cellular phone network

Stand-alone systems are the original preserve of photovoltaics. The simplest installations consist of a PV module and a device that consumes direct current, such as a water pump. Photovoltaic systems are straightforward to install and benefit from low operating costs. In remote regions, located at great distances from the power grid, they are therefore often unrivalled on price – particularly when the only alternatives are diesel generators that consume expensive fuel. Continually falling module prices together with rising prices for fossil fuels are also clearing a path for such systems in other markets.

If small, stand-alone installations require a 24h power supply, the PV plant is combined with a battery system, as is the case in weather stations, navigational aids and transmitter masts. Here, electronic charge controllers are employed to ensure that the power supplied by (mostly individual) PV modules is stored in the batteries as efficiently as possible. DC power consuming equipment (such as lamps and refrigerators) is connected to the charge controller and is thus supplied either by the solar power generated at a given moment or by power stored in the batteries.

This principle is that of the “solar home system”.

Backup systems (e.g. diesel or vegetable oil generators) improve supply security.

This has led to the creation of hybrid systems that can be used, for example, in hunting cabins and refuges, and even on large yachts.

With the development of PV technology, stand-alone systems have grown into autonomous grids and have become more diverse. If intended to supply power to schools, hospitals, entire villages or even small islands, the PV systems are usually supplemented by small wind turbine generator systems as well as batteries and diesel or vegetable oil generators. Biogas plants can also be integrated into these autonomous grids.

As such grids increase in size, cheap devices that consume alternating current (refrigerators, TVs and other household appliances) are used in addition to those that consume direct current, meaning that inverters become necessary alongside charge controllers.

Using solar energy to support the power grid: Since the grid power supply is unreliable, a PV installation in Chennai (India) is used to produce power during the day. At night, a diesel generator ensures electricity is still available. Surplus solar power is stored in a battery.

It is not only possible to structure hybrid systems as either pure DC systems or mixed AC/DC systems, pure AC configurations are also available that are flexible and can be expanded. Special inverters are needed for such systems. A stand-alone inverter primarily has two tasks: It charges the batteries to store any solar power not used immediately and creates a stable AC network.

Additional PV systems and the fuel driven generators feed into the AC network, coupled with a wind turbine generator system (preferably also with a special inverter) or biogas plant when large amounts of power are needed. The better the levels of insolation and wind complement one another over the course of a day, week or year, the less frequently the back-up generator is used.

If a hybrid system supplies an entire village, a micro grid is created. Several of these stand-alone systems can then be combined to form a mini grid. Stand-alone systems gradually grow together into ever larger grid units, thus representing a major contribution to rural electrification in developing countries.

Bilene (Mozambique): DC system with a rated output of 28 W

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Inverter and PV System Technology 2012 路 Industry Guide

Protection against Lightning and Overvoltage

Stand-alone PV systems System

Power range

Application

DC loads

Simple DC motors, fountain pumps, fans

Pumps cathodic protection

Pumps with power conditioning, cathodic protection

AC loads

Larger AC pumps, or other AC drives

DC loads

Miniature appliances, pocket calculators, watches Mobile applications, telecom, medical refrigeration, bus shelter lights, small SHSs

DC loads

Protection against Lightning and Overvoltage Highly excessive voltages and currents can threaten the operation of a PV plant. Such surges are mainly caused by lightning strikes, but also by faults in the grid. Ensuring a path to earth for any lightning or currents caused by overvoltage is an extremely important factor in PV plant protection.

Autonomous DC loads, emergency telephones, clocks (with load management)

DC loads

Fitting protection against lightning and overvoltage

DC loads

Remote homes, schools, hospitals - with additional power source (diesel / wind) in larger installations

PV module(s)

Inverter

Lead-acid or NiCd battery, capacitor

Additional power source (diesel, wind)

Bridging bottlenecks Between PV plants that supply standalone systems and those that feed into the public grid come installations that generate power in parallel to the grid (grid-compatible parallel operation).

Grid-parallel operation is necessary anywhere where a public grid exists but the power supply is unreliable. Moreover, such systems are also practical in situations where a large power consumer (such as a factory) is connected to a weak grid spur and the power demand regularly exceeds the capacity of the grid connection. In both cases, photovoltaics assists in stabilizing the power grid and bridging bottlenecks in supply.

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<0.1 W 1W 10 W 100 W 1,000 W >10,000 W

AC loads

DC-DC converter

Charge controller, battery monitoring

To date, this task has been performed by diesel generators. But in view of rising oil prices and PV generation costs that continue to fall, it makes far more practical sense to install PV systems. This is especially true in regions with high levels of insolation. In many cases, photovoltaics is already capable of generating power for profit in these regions, as illustrated by this simple case study: A factory in India that operates around the clock, but is plagued by frequent power failures, relies on a diesel generator to supply power during the power cuts.

This generator can produce power at all times of the day for 20 Euro cents/kWh. Thanks to the high levels of insolation there, a PV installation is able to generate electricity throughout the day for 10 Euro cents/kWh. Both systems operate in parallel to the grid. During the day, the PV installation has priority, while at night the diesel generator is responsible for securing the power supply. Surplus solar power produced during the day can also be stored using a battery system, increasing the availability of that power even further.

A progression of this system is based on a situation where the PV installation produces distinctly more power than the factory requires and consists of two PV generators. The larger of these supplies the factory with electricity throughout the day and feeds any surplus power into the battery system. The smaller PV generator is tasked solely with ensuring that the battery is fully charged, so that enough power is available during the night. Wind energy installations can also be connected to this system and supply power to the factory. The diesel generator is currently still needed as a backup power source, but provided the latest radical developments in battery technology continue, it will foreseeably become redundant in the medium term.

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Inverter and PV System Technology 2012 · Industry Guide

Protection against Lightning and Overvoltage

Surge protection measure

Surge protection measure: DC cables of the same string bundled together to avoid loops in which voltage surges can be induced.

In principal, a PV plant does not generally increase the risk of a building being struck by lightning. A separate lightning protection system does not necessarily need to be constructed simply because a PV plant has been installed. Nevertheless, VdS (the German institute for fire protection and security) recommends installing a lightning and overvoltage protection system for all plants with a capacity of ten kilowatts or more. In a given case, the risks should be assessed in order to enable a decision in favor of or against the construction of a lightning and overvoltage protection system. If the building on which the PV plant is constructed is already equipped with a lightning protection system (e.g. a public building), the PV plant must be integrated into the protection concept.

Lightning protection system guaranteeing potential equalization in the inverter

The standard DIN EN 62305 (VDE 0185305):2006-10 provides a comprehensive approach to internal and external lightning protection for buildings and systems.

In particular, the supplementary sheets to this European standard offer practical support when deciding whether or not to install a lightning protection system, as well as details on how to install such systems properly. Photovoltaic installations are primarily discussed in Supplement 5 “Lightning and surge protection for PV power supply systems”.

External lightning protection includes all measures for arresting lightning and conducting it to ground, and consists of a lightning current arrester, a down lead capable of carrying lightning and a grounding system which distributes the lightning current in the earth.

Priority must be given to preventing the lightning from directly hitting the modules. This is first and foremost necessary when the PV generator has been installed in an exposed area (elevated on a flat roof, for example). Rods or wires are used as lightning current arresters, and the core shadow of these should not be cast on the modules as far as this is possible. Somewhat smaller air terminal rods are, therefore, placed in front of the solar modules and somewhat larger ones are placed behind the modules. The exact number and spacing of the air terminal rods is given by the class of protection desired and is calculated using methods such as the “rolling sphere method”.

Indirect effects

Reverse current and electric arcs

The probability of indirect lightning effects occurring is significantly higher than that of a direct lightning strike. This is because every lightning strike within a one kilometer radius can generate current flow in the modules, module cables and in the main DC cable by means of induction. Conductive and capacitive coupling are also possible and can equally cause overvoltage.

Increased currents can also occur if there is a voltage drop in a string, caused for example by shading or a short circuit. If this happens, the parallel-connected strings will function like an external power source which drives a fault current in the direction of consumption (reverse current) through the modules of the defective string. If the reverse current resistance of the modules is exceeded they will start to heat up, so string diodes are used to prevent such reverse currents. Many PV plants today are, however, built without string diodes, as most modules now have higher reverse current resistance and will easily withstand reverse current of 10 to 20 amps.

An integrated lightning protection system comprising measures and equipment within the PV plant and in the building is, therefore, required. Its fundamental purpose is to prevent inductive coupling and provide a path to earth for currents caused by overvoltage.

In order to keep coupling in the module cables to a minimum, the area of the open conductor loops in the generator circuit must be as small as possible. The outgoing and return lines of the strings are, therefore, laid as close as possible to each other. The use of shielded single lines also reduces the risk of lightning effects.

Surge protection devices (SPD) not only prevent inductive coupling but also the occurrence of grid-side overvoltage, and are normally built into the generator junction box. Because varistors used as voltage dependent resistors can age due to leakage currents, the combination of two varistors and a spark discharger in Y connection is considered the safest longterm protection against overvoltage.

Since direct current and DC voltage are generated in a PV plant, there is a danger that non-self-extinguishing arcs could be created, which could cause fire. This danger is not present in an alternating current circuit because the regular zero crossing of the alternating current’s sine curve immediately extinguishes any electric arc created. The electrical connections in the DC circuit of a PV plant must, therefore, be extremely secure, because a loose connection can lead to sparking and, consequently, trigger an electric arc. As a result, when laying the DC cables of a PV plant it is standard to protect them from short circuit and ground leakages. This is achieved by tidy cable routing (e.g. not running unprotected over sharp edges) and the use of separate positive and negative cables, as well as double cable insulation. The DC cables used should be tested to “PV1-F” standards and marked accordingly.

String fuses in the GJB can also generally prevent the cables from becoming overloaded in the event of faults. These are intended to reduce the risk of electric arcs.

Overvoltage protection modules (red and blue) in generator junction boxes

Lightning damage

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Inverter and PV System Technology 2012 · Industry Guide

Cables and Connectors

Cables and Connectors The electrical connections in a system may be inconspicuous, but their effects should not be underestimated. As a relatively large number of electrical connections are required in order to connect the modules of a PV plant to the inverter, the losses at contact points can add up. Long-lasting, secure cable connections with low contact resistances are necessary to avoid defects, losses and accidents.

Example of strings connected in parallel

Cables for thin-film solar modules

A PV plant’s electrics consist of the DC cables between modules, generator junction box and inverter, and the AC cable running from inverter to grid. DC cabling is composed of two single-core, doubleinsulated cables, which should be tested to „PV1-F“ standards, and is almost exclusively laid outside, which means that the insulation must be weatherproof. A threecore AC cable is used for connection to the grid if a single-phase inverter is used, and a five-core cable is used for three-phase feed-in.

Individual modules are connected using cables to form the PV generator. The module cables are connected into a string which leads into the generator junction box, and a main DC cable connects the GJB to the inverter. In order to eliminate the risk of ground faults and short circuits, the positive and negative cables, each with double insulation, need to be laid separately.

Solar cables, which are UV and weather resistant and can be used within a large temperature range, are laid outside.

Single-core cables with a maximum permissible DC voltage of 1.8 kV and a temperature range from –40°C to +90°C are the norm here. A metal mesh encasing the cables improves shielding and overvoltage protection, and their insulation must not only be able to withstand thermal but also mechanical loads. As a consequence, plastics which have been cross-linked using an electron beam are increasingly used today. The cross-section of the cables should be proportioned such that losses incurred in nominal operation do not exceed 1%. String cables usually have a cross-section of four to six square millimeters.

PV connector for toolfree assembly

42

Losses add up Connection technology has needed to develop rapidly over the last few years, as inadequate contacting can cause electric arcs. Secure connections are required that will conduct current fault-free for as long as 20 years . The contacts must also show permanently low contact resistance.

Since many plug connectors are required in order to cable a PV plant, every single connection should cause as little loss as possible, so that losses do not accumulate.

Given the precious nature of the solar power acquired from the PV plant, as little energy as possible should be lost.

Screw terminals and spring clamp connectors (e.g. in the module junction boxes and for connection to the inverter) are gradually being replaced by special, shockproof plug connectors, which simplify connection between modules and with the string cables.

Cabling thin-film solar modules

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Storage and Energy Management

Inverter and PV System Technology 2012 ¡ Industry Guide

Storage and Energy Management

Cabling work at a ground-mounted installation

The on-site consumption of solar power by those who generate it increases the distributed supply of electricity. In Germany, for example, special remuneration is offered if the power generated is consumed by owners â&#x20AC;&#x153;in the immediate vicinity of the installationâ&#x20AC;?. One aim of this policy is to ease the burden on the grids, as the increasing spread of grid-connected photovoltaic systems exacerbates the problem of excess voltage. It is not always possible to consume surplus power immediately, however, making new storage technologies and intelligent household appliances a necessity.

Lead-acid gel battery

Crimp connection (crimping) has proven itself to be a safe alternative for attaching connectors and bushes to the cables.

It is used both in the work carried out by fitters on the roof and in the production of preassembled cables in the factory.

Here, litz wire is pressure bonded with a contact using a crimping tool, which causes both to undergo plastic deformation creating a durable connection.

A recently developed special plug makes it possible to secure connections without the use of a special tool. In this instance, the stripped conductor is fed through the cable gland in the spring-loaded connector. Subsequently, the spring leg is pushed down by thumb until it locks into place. The locked cable gland thus secures the connection permanently.

Plug connectors and sockets are now also available with welded cables. Such connections cannot, however, be carried out during installation work on the roof, but only during production in the factory.

Another recent development are preassembled circular connection systems for the AC range. These are intended to reduce the high levels of installation work required when several inverters are used within one plant.

44

Standards for plug connectors Since PV modules generally come equipped with preassembled plug connectors, several modules can easily be connected to form a string. Connecting these strings to the inverter or generator junction box, on the other hand, is not always straightforward. A variety of different cable connectors are available on the market, and as yet no standards have been established for these interconnection systems.

Plug connectors from different manufacturers are usually either completely incompatible or they fail to provide a connection that will remain permanently snug. If the connector fits too tightly, this can cause the insulating plastic parts to break. A loose fit, on the other hand, poses the risk of creating high contact resistance. Consequently, yield will drop and the areas around the connection will heat up, causing the connector itself to melt.

Strings connected in parallel

When connecting a plug with a socket from a different manufacturer, a crossover connection is created, which can generally only be proved to be reliable if complex, expensive tests are performed. In addition to measuring the contact resistance and determining the connection strength, accelerating aging tests and weather exposure tests must also be carried out.

Such tests will make it clear whether or not the different materials are compatible. This concerns both the metals used to manufacture the contacts and the plastic materials employed.

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Inverter and PV System Technology 2012 · Industry Guide

Storage and Energy Management

Potential use of solar power in private households 1.

1. Solar installation 2. Energy management 3. Consumption devices 4. Storage system (battery) 3.

5. Consumption meter 6. Feed-in meter 7. Energy utility 8. Power grid I.

II.

4.

2.

In view of the steadily falling feed-in tariffs, it is becoming increasingly important for installation owners to consume as much solar power as possible in their own homes. On-site consumption (I.), which can be increased by means of load shifting, takes precedence over storage (II.), as this entails relatively large losses. Solar power is only fed into the grid when the battery is fully charged and the consumption devices do not require power (III.). Purchasing relatively expensive electricity from the grid (IV.) is the least favorable option, and should only be considered if the PV installation is supplying too little power and the battery is run down.

III. 7.

IV.

00123467

5.

8.

00123467

6.

Source: Volker Quaschning, Regenerative Energiesysteme, 7th edition, Hanser Verlag München 2011

Lead-acid gel battery production

The strong growth of photovoltaics in Germany has now led to a situation where excess solar power is produced in some regions during the middle of the day. Power generation is becoming regionally concentrated during specific periods. Given that, in most cases, the power supplied by the PV plants dramatically exceeds the demand of nearby consumers, it is impossible to avoid creating such a surplus simply by introducing provisions for on-site consumption. As the number of new PV installations increases year on year, the number of regions where more solar power is generated than consumed is also set to rise.

The portion of solar power that can neither be absorbed by the grid nor used directly on site therefore needs to be stored. Batteries are the primary contenders for this task, as they have proven their worth over decades of use and can be employed in decentralized systems.

Owing to topographical restrictions in Germany, cross-regional storage in reservoirs (pumped storage hydroelectric power stations) is only possible to a very limited degree. Compressed air energy storage represents one alternative technology that, in principle, holds great potential, but its efficiency is still in need of improvement.

Converting solar power into chemical energy (e.g. by means of electrochemical hydrogen generation) incurs relatively high losses, but does bring with it the advantage that energy can be stored for long periods of time. Hydrogen can be converted into either electricity or heat and can also be used as fuel, directly substituting petroleum products. Converting hydrogen into methane would achieve an even higher energy density and thus tap into an even greater storage capacity.

In this case, the efficiency of converting the energy does drop somewhat, but this would still be acceptable given that free sunlight is the energy’s source.

Batteries The only type of instant storage currently available is that of secondary electrochemical cells, generally known as (rechargeable) batteries. However, the unavoidable phenomenon of self-discharge in batteries means that they are only suited to storing solar power for short and medium periods.

Moreover, the lifespan of a battery is limited by its cycle life, not forgetting that the number of possible charge cycles falls as the depth of discharge increases. The battery therefore needs to be protected against over-discharge. In lead-acid storThe latest developments in technology age batteries, for example, full discharge do not allow us to foresee which storage converts the lead sulfate into a crystalline systems will triumph in the long term. The form which is only partly dissolved when most likely scenario will involve a mixture the battery is charged again, causing of small, distributed, short-term storpermanent damage. age systems and large, seasonal storage systems. Ultimately, if the intention is to What is more, the capacity that can be make photovoltaics a mainstay of German extracted from an accumulator decreases power supply, a solution must be found to as the discharge current becomes more store the surpluses generated in summer powerful. for use during winter.

Lead-acid storage batteries are cheapest and are therefore most frequently used.

They are filled with an electrolyte of dilute sulfuric acid, meaning that if the final charge voltage is exceeded, gassing may occur. When this happens, oxygen forms on the positive electrode and hydrogen on the negative. These two gases then form explosive oxyhydrogen. Gassing also leads to the gradual loss of water, which needs to be regularly refilled. Overall, the cycle life of lead-acid storage batteries is relatively low.

basis, lead-acid gel batteries will need to be changed after around just 1,000 cycles.

Lithium-ion batteries achieve markedly higher cycle lives. If discharged and recharged daily, they can reach a lifespan of 20 years, equating to 7,000 charge cycles.

Their special features include high energy densities and low self-discharge rates.

They also withstand high charging currents, and can therefore be charged very quickly. These advantages currently make them ideal storage batteries for homes In order to increase its lifespan, the elecand electric cars. Prices for such batteries trolyte can be thickened using additives to are still too high, however, and will not fall form a gel. Lead-acid gel batteries can be until mass production levels are achieved. assembled fully sealed, meaning that they are leak proof. In this case no gas is able Redox flow batteries to escape, but lead-acid gel batteries may dry out as a result of gassing. A special Both types of storage battery (leadcharge controller is therefore necessary to acid and lithium-ion) share the common manage the final charge voltage very pre- feature that their electrodes undergo cisely. Lead-acid gel batteries have double chemical conversion during charging the lifespan of lead-acid storage batteries and discharging, and therefore slowly with liquid electrolytes. They allow around degenerate. Redox flow batteries avoid 2,000 cycles, provided no more than 30% this. A relatively new development, these of the capacity is discharged each time. If batteries combine the properties of the 50% of the capacity is drawn on a regular accumulator with those of the fuel cell.

Working principle of a redox flow battery

The reactants are each dissolved in an electrolyte and circulate separately. These two electrolytes are pumped through a cell in which ions are exchanged. This cell is divided by a membrane that only allows ions to pass through it, thus preventing the reactants becoming mixed.

The electrolytes that store energy in redox flow batteries are kept in separate tanks.

As a result, the quantity of energy and the output can be scaled independently of one another. Redox flow batteries are characterized by their high efficiency and long life expectancy.

The capacity of the redox flow storage systems that are shortly due to be launched on the market lies between 3 and 13 kWh. Apartment buildings and commercial establishments require larger units, providing an opening for those redox flow batteries that are currently offered in 200 kWh modules. Here, additional modules can be added to increase the capacity.

As both lithium-ion batteries and redox flow batteries are still at an early stage of development and are relatively expensive, the lead-acid battery is still the most economical way to store solar power, despite its short cycle life.

Production of lead-acid gel batteries

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Inverter and PV System Technology 2012 · Industry Guide

Storage and Energy Management

Battery systems determined by connection point AC connected PV battery system 1.

4.

3.

2.

7.

00123467

8.

00123467

Lithium-ion battery

5.

Storage systems Overall, storing solar power in batteries is a relatively expensive enterprise. It currently costs roughly as much to store a kilowatt hour of electricity as it does to generate it from sunlight. The specific costs of storage (in Euro cents/kWh) are not the sole criterion, however. If the goal is to operate a battery system as profitably as possible, cycle life, the output of the PV plant and household energy requirements must also be considered.

Rising personal consumption of solar power has made battery storage a new and promising market segment.

In order to incorporate batteries into a PV system, special storage systems are required which consolidate the storage battery with the necessary power electronics. These have only recently become available on the market. They not only differ according to battery type, but also based on how they are installed. Some systems are incorporated into the house’s AC circuit, while others are integrated into the PV plant’s DC circuit.

Integrating the system into the AC circuit has the advantage that as much additional capacity as desired can be added at a later date, irrespective of the PV capacity installed. A battery inverter is needed in addition to the PV inverter, meaning that relatively high outlay is required, but such systems come with the extra advantage that power from the grid can be fed into them more easily, as the battery inverter operates bidirectionally.

Incorporation into the DC circuit also has two advantages: the system costs are lower and the storage efficiency is higher.

This method requires the installation of a PV inverter and a pair of DC/DC converters. They set the voltages of the PV system and the battery at precisely the level that is best for the inverter. To simplify matters, they can be installed in the metal cabinet that houses the battery.

Despite the high investment costs involved, battery capacity should be selected to enable as much solar power as possible to be consumed on site. By way of example, for a 4 kW plant and annual energy consumption of 4,000 kWh, a capacity of 6 to 7 kWh is recommended if the quota of on-site consumption is intended to reach 70%. A quota of over 30% will be virtually impossible to achieve without using storage, unless the solar power is also used to heat water. Combinations of photovoltaics, heat pumps for water heating and intelligent energy management, for instance, can achieve on-site solar power consumption rates of up to 50%, even without storage systems.

Of course, checks should always be made to examine whether or not solar thermal installations will represent the most economical solution for the actual needs and conditions of the site.

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6.

DC connected PV battery system 1.

2.

4.

5.

7.

2.

8.

00123467

00123467

3.

Depending on their type, battery systems either form part of the household circuit (top diagram) or the intermediate electric circuit of the photovoltaic generator (bottom diagram). This influences efficiency, system costs and how existing solar installations can be upgraded.

1. Solar installation 2. Inverter 3. Production meter 4. Consumer 5. Inverter/rectifier 6. Battery system 7. Bidirectional meter 8. Public grid

6.

1. Solar installation 2. DC converter 3. Battery system 4. Inverter 5. Production meter 6. Consumer 7. Bidirectional meter 8. Public grid

Source: Fraunhofer ISE

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Inverter and PV System Technology 2012 · Industry Guide As solar power generation becomes increasingly less expensive, it may be practical to utilize this power not only to operate household devices (I.), but also to back up the heating system (II.). Surplus power can then be fed into the grid (III.). However, since remuneration for this is becoming ever lower, the option of producers marketing their own electricity and thus creating a distributed power supply is fast developing – but this requires an appropriate legislative framework.

Storage and Energy Management

Photovoltaic back-up heating 1. Solar installation 1.

2. Energy management 3. Consumption devices 4. Heat pump 5. Combi heat storage tank 6. Shower 7. Heating system 8. Consumption meter 9. Feed-in meter 10. Energy utility 11. Power grid 3.

6.

I.

III.

II. 5.

2.

7.

4.

00123467

00123467

10.

11.

8.

9.

Source: Volker Quaschning, Regenerative Energiesysteme, 7th edition, Hanser Verlag München 2011

Heat accumulators and heat pumps

a well-insulated house with a living area of 120 m2 and heating requirements of 40 kWh/m2. This calculation is unrealistic, One very simple way of storing energy is however, as supply and demand do not to store heat. As buffer storage is already coincide: In winter, when the greatest deavailable in some houses in the form of hot water tanks, surplus solar power could mand is placed on the heat pump, the PV also be converted into heat by conducting plant will furnish the least electricity. it through an immersion heater inserted The conditions are somewhat different if into the storage tank. As long as the the heat pump is used to provide cooling production of solar power is significantly more expensive than producing hot water, via an air-conditioning unit. In this case, the periods of energy production and this will remain a very wasteful use of consumption do correlate if power from energy. Nevertheless, falling solar energy the photovoltaic plant supplies electricity generation costs combined with rising for heat pump cooling during the summer prices for raw materials will slowly close months. In the USA, for example, heat this gap. pump cooling is already widespread.

A far more efficient application of surplus Irrespective of their intended use, heat solar energy is in a heat pump. If this pumps are not suitable for storing energy pump is capable of generating 3 kWh of over the long term, but merely represent a heat from 1 kWh of electricity, 1.600 kWh component of good energy management. should theoretically be sufficient to heat

Energy management It is considerably easier to generate solar power than to store it, as this entails relatively complex installation procedures and unavoidable losses. In order to complement the storage options, as much energy as possible must therefore be consumed on site and the conditions for marketing the power must be made as favorable as possible. This situation will then replace the current practice of unreservedly feeding power straight into the grid. If the statutory feed-in tariffs were to be abolished, or sink so low that it became unviable to feed all the solar power generated into the grid, this custom would die away. Grid feed-in will then only be sensible under certain circumstances and should only be considered if other options are not available.

Building energy management system

Load shifting can help to increase on-site consumption rates. For example, large household devices that do not require power at a given time might only be switched on when solar power is in plentiful supply. Washing machines, tumble driers and freezers can thus contribute to improving the coordination between demand for power and supply. These energy management systems need to succeed in changing the consumption patterns of the average consumer, i.e. to drive them away from simply using household power at any time at the push of a button. They must clearly indicate the costs per kilowatt for each device at a given moment and ideally offer alternative operating times within the shortest possible time frame.

Favorable sales conditions will become possible if the tariff for purchasing power

from the grid increases while the solar power produced on house roofs becomes cheaper at the same time. This power can then be sold to neighbors at a price below the electricity tariff, as the short distances will mean that grid fees are waived.

As a last resort, feeding power into the grid remains an option. This would struggle to contribute to PV plant profitability, however, as solar surpluses are produced by many PV installations simultaneously.

Increasing on-site consumption through load shifting and solar heating, selling power, storing it, and feeding it into the grid are the options available to the energy management systems of the future. If possible, these systems should be able to independently decide on which type of use would be most beneficial to PV plant profitability at which times, and to activate Given the fact that storing power in consumption devices and storage systems batteries will remain relatively expensive as required. This concept demands a great for the foreseeable future, it should be deal of the systems technology, which will avoided if at all possible. If several other inevitably change over time. Gradually inpossibilities for use are in place, only a verters will be replaced by energy managesmall battery capacity will be required. ment systems. Developing these is the task that now lies ahead.

Only once these two channels have been exhausted should solar power be used in hot water tanks or heat pumps. Using solar power for heating means using solar energy under its value. This is why it ranks third in the hierarchy of solar power exploitation.

The development of storage technologies means that individual family homes are becoming increasingly energy self-sufficient.

Energy management systems must be compatible with the user’s daily routine.

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Inverter and PV System Technology 2012 路 Industry Guide

Inhaltsangabe

The Companies

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Overview

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Overview Companies and brands presented at a glance (in order of appearance)

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Danfoss Solar Inverters

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DEHN + SÖHNE GmbH + Co. KG.

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Diehl AKO

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Emerson Solar Europe

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Enphase Energy

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Fronius Deutschland GmbH

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KACO new energy GmbH

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KOSTAL Industrie Electrik GmbH

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KOSTAL Solar Electric GmbH

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meteocontrol

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Multi-Contact AG

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Phoenix Contact GmbH & Co. KG

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Business areas: inverters, connection technology, LOP, housing, monitoring/supervision

PV power plant (94 kWp) installed on the roof of an aircraft shelter in France and powered by ABB string inverters, PVS300

ABB Oy, Drives Address: Hiomotie 13 00380 Helsinki · Finland Phone: +358 (0)10 22 11 Email: feedbackmaster.solar@fi.abb.com Web: www.abb.com/solar Year founded: formed in 1988, merger of Swiss and Swedish engineering companies with predecessors founded in 1883 and 1891 Employees: 135,000 (ABB Group)

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ABB

181 kW PV power plant on the roof of the ABB factory in Finland (opposite, top)

Companies: xxx

Inverters for the Entire Spectrum without Losing a Watt ABB offers a comprehensive solar inverter portfolio. With decades of experience in power technology products, ABB has the know-how, life-cycle services and personnel to support PV installations worldwide for years to come.

ABB has been working for decades to offer products and solutions to reduce the environmental impact of energy systems.

Now with the growth in photovoltaic (PV) power systems, ABB provides leading edge solutions from low voltage components to frequency converters, medium voltage transformers, switchgears, and now solar inverters. Whether the PV power systems are industrial, commercial or residential, ABB’s high-quality products, systems and services provide optimum return on investment.

Powerful solar inverters with global presence The ABB solar inverter utilizes over 40 years of advances in inverter and power converter technology that has contributed to ABB becoming the world leader in frequency converters and one of the biggest suppliers of wind turbine converters. ABB offers a complete portfolio of solar inverters from small transformerless single-phase string inverters up to hundreds of kilowatt transformerless central inverters. The portfolio is complemented by the megawatt station: a containerized turnkey solution designed for large-scale solar power generation.

Furthermore, ABB solar inverters are supported through a worldwide sales and

services network that provides a complete range of life-cycle services.

ABB central inverters for photovoltaic power plants ABB central inverters are aimed at PV power plants and large industrial and commercial buildings. Based on ABB’s market-leading technology platform in frequency converters – the most widely used frequency converters in the market – the inverters comprise proven components with a long track record of performance excellence in demanding applications and harsh environments. Equipped with extensive electrical and mechanical protection, the inverters are engineered to provide a long and reliable service life of at least 20 years. A wide range of options like remote monitoring with string current measurements, fieldbus connections and integrated DC cabinets are available.

Rapidly increased interest from the market has confirmed that there is solid demand for compact and modular inverters based on a proven technology platform that deliver high maximum efficiency and extremely low auxiliary power consumption. The inverters are available from 100 to 500 kW.

ABB string inverters for residential buildings ABB string inverters are designed for PV systems installed on residential, commercial or industrial buildings. The inverter’s all-in-one design includes the necessary protection functions built into the inverter, reducing the need for costly and spaceconsuming external protection devices and larger enclosures. The result is a more compact, reliable, safer and cost-effective solution, especially in installations using multiple inverters. The heart of the inverter is the intuitive control unit equipped with a graphical display. It offers a comprehensive range of key functionalities that are easy to use with built-in assistants and a help menu. The control unit has three different mounting options. It can be integrated in the inverter housing or mounted separately on a wall to monitor inverter performance from outside the installation room. It can also be wirelessly connected to enable the inverter to be installed in a remote part of the site and monitored wirelessly from inside the main building. The inverters are available from 3.3 to 8 kW.

Turnkey solution for large-scale solar power generation The ABB megawatt station design capitalizes on ABB’s long experience in the development and manufacture of secondary substations for electrical authorities and major end-users worldwide in conventional power transmission installations.

A station houses two 500 kW ABB central inverters, an optimized transformer, medium voltage switchgear, monitoring system and solar generator terminal boxes, which connect a photovoltaic power plant to a medium voltage electricity grid easily and rapidly. All components within the new megawatt station are part of ABB’s product portfolio. The steel-framed insulated container comes complete with a concrete foundation, also designed and produced by ABB. The station’s thermal insulation enables operation in harsh temperature and humidity environments and is designed for at least 20 years of operation.

ABB is a leader in power and automation technologies that enable utility and industry customers to improve their performance while lowering environmental impact. The ABB Group of companies operates in around 100 countries and employs about 130,000 people.

ABB central inverter, PVS800, 500 kW

ABB megawatt station, PVS800-MWS

ABB string inverter, PVS300, with control unit

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Business areas: inverters, LOP, connection technology

Business areas: PV generators, inverters, storage technologies, planning and grid integration, monitoring/supervision, power plant control

Advanced Energy

AEG Power Solutions

AE’s solar energy business delivers Solaron® and PV Powered™ inverters, complementary BoS products, and O&M services that enable our customers to secure more solar projects and increase their earnings.

AEG Power Solutions offers a comprehensive portfolio of premium power supply and control products, systems, solutions and services.

Built-in cooperation with abakus solar AG, a solar plant in Hungen, Germany

AE’s PowerStations generate electricity dependably, optimize Levelized Cost of Energy (LCOE) and help stabilize grid operation.

AEG Power Solutions – Competence Center in Warstein-Belecke

AE Solar Energy’s inverter manufacturing team

20 MW solar field with AE Solaron inverters

AE Solar Energy Address: 20720 Brinson Blvd.

Bend, OR. 97701 · USA Phone: +1 877 312-3832 Fax: +1 541 312-3840 Email: sales.support@aei.com Web: www.advanced-energy.com/solarenergy Year founded: 1981 Employees: 1,500

Customer experience AE Solar Energy enables utility-scale, commercial, and residential solar project stakeholders to offer system owners a lower Levelized Cost of Energy (LCOE) and improved peace of mind since their PV system will deliver on long-term production goals. With more than 30 years of leadership in innovation and in delivering energy solutions combined with a legendary reputation for customer service, AE has become a trusted partner to solar project developers, financiers and beneficiaries around the globe.

Innovation AE is never satisfied: From our roots in reliability and LCOE to continually improving our quality, systems and people, we ensure that energy is delivered, period. We pioneer improvements in distributed generation, grid interactivity performance, utility interactive functionality, and energy management solutions.

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From the solar modules in the field to the tie point at the utility grid, AEG Power Solutions has all the electrical equipment necessary to construct a solar power plant.

The heart of any plant is the central inverter, designed to convert DC power from the solar panels to AC power for the utility grid.

Energy Delivered™ AE delivers highly reliable and efficient inverters designed with an architecture optimized to deliver the LCOE. Our simplified BoS solutions reduce system design support, project management time and increase savings on installation. Simply put, AE delivers life-cycle performance.

Solar site solutions AE delivers whole-site operations and maintenance service plans that increase the reliability of customers’ PV systems.

AE global services is dedicated to responding quickly to issues, whether that means rolling a truck, providing phone support or anything else. We provide application engineering support and warranties for up to 20 years, partnering with customers for the entire project life-cycle.

AEG Power Solutions offers two different models of central inverters, the PV.250 and the PV.500. The first model produces 250 kVA of output power, the second 500 kVA. These inverters have an outstanding conversion efficiency, as measured by the Fraunhofer Institute for Solar Energy Systems.

Solar inverter Protect PV.500

In addition to the inverters, the TKS-C can also include MV transformers and MV switchgear to allow for connection to the tie point of a utility grid.

The TKS-C also boasts an advanced monitoring, metering, and control system.

Among its many features, the MM&C can The basic models of the PV.250 and PV.500 respond to commands sent by the grid opcentral inverters are designed for indoor erator, altering the power to match minuteuse. More advanced models can be placed by-minute requirements of the utility grid. outdoors directly.

Finally, the use of intelligent combiner The most advanced models are included as boxes can greatly expand the ability of the part of the turnkey solutions in containers, MM&C system. These boxes, called PV.IcX, abbreviated TKS-C. Each TKS-C is a concrete not only combine DC inputs to the inverter, container with room for two inverters and but also provide the data to detect stringother equipment. The TKS-C 500 has two level problems in the solar panels. Fixing PV.250 inverters, while the TKS-C 1000 has these problems in a timely manner makes solar plants more profitable. two PV.500 inverters.

AEG Power Solutions GmbH Address: Emil-Siepmann-Straße 32 59581 Warstein-Belecke · Germany Phone: +49 (0)2902 763-141 Fax: +49 (0)2902 763-1201 Email: solar@aegps.com Web: www.aegps.com Year founded: 1946

Sales volume: 428 million euros (2011, worldwide) Employees: > 1,650 (2011, worldwide)

Combiner box PV.IcX

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Business areas: inverters, MLPM, connection technology, LOP, housing, planning and grid integration, monitoring/supervision, power plant control, software/IT

Business areas: inverters, connection technology, planning and grid integration, monitoring/supervision, software/IT, communication services

Answer Drives Srl

Bonfiglioli

Ansaldo Sistemi Industriali SpA’s answer to solar plants’ needs.

Answer Drives Srl, a wholly owned subsidiary of Ansaldo Sistemi Industriali, has the specific mission to conquer the emerging renewable energy market.

The highest standards mean maximum efficiency.

A worldwide presence and a vast range of solutions for photovoltaic systems: Bonfiglioli know-how is at the service of excellence.

The Solargate5000 for large-scale solar power stations with its basic building block: the GT3000

Part of a 6 MW PV plant in Italy

A Bonfiglioli RPS TL Modular Outdoor Series inverter Robust containerized solutions for harsh environments

Answer Drives Srl – an Ansaldo Sistemi Industriali SpA company Address: SS 11 – Via Cà Sordis 4 36054 Montebello, Vicentino (VI) · Italy Phone: +39 0444 449-268 Fax: +39 0444 449-276 Email: info@answerdrives.com Web: www.answerdrives.com Year founded: 2007 Employees: 70

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Based in Montebello Vicentino (VI), Italy, Answer Drives was established in 2007, and in 2009 the company launched its plug-and-play solution for large-scale solar plants: the Solargate5000, which gained the appreciation and esteem of the market thanks to its outstanding performance and reliability.

The Solargate5000 ensures extremely low harmonics, maximizing grid stability and achieving a near unity, adjustable power factor as well as benefitting from a European efficiency of 98% due to the MIRO function. The SolarGate inverter family comprises four classes of inverter available in two versions – low voltage (400 V) for roof-top commercial installations and medium voltage (10/20 kV) for utility applications. The inverters are certified according to EN61000-6-3, EN61000-6-4 and are also CE compliant.

The grid connection meets CEI 0-16 and Real Decreto RD1663/2000 standards, and the interface is user-friendly and intuitive. The inverter is equipped with a series of protection devices to safeguard and guarantee constant performance. In response to the high demand for solar plants in extremely hot climates, Answer Drives proposes a water-cooled version of the inverter station.

The strength of the company lies in working together with customers to develop innovative solutions that really fit the customer’s business and plant goals, allowing them to achieve a rapid return on investment.

In addition to offering state-of-the-art technology, as part of Ansaldo Sistemi Industriali, Answer Drives also offers customers the guarantee that they will receive the support they need for the entire life-cycle of the plant.

Answer Drives Srl operates in the solar industry with the total dedication and customer orientation that are a result of the know-how and experience inherited from Ansaldo Sistemi Industriali SpA.

Bonfiglioli’s worldwide presence

Bonfiglioli is an international group that has been producing complete solutions for industry and renewable energy for over 50 years. Bonfiglioli inverters and PV components are developed and made 100% by the Bonfiglioli Vectron center of excellence in Germany. All products are carefully assembled and tested to deliver superior quality and lasting efficiency.

Thanks to Bonfiglioli’s global network and excellent solutions, prestigious EPCs and IPPs have trusted the group to supply inverters for large PV fields in Europe, Asia and the USA. Bonfiglioli supplied inverters for the world’s then largest photovoltaic field (51 MW) in 2008 in Spain and for Europe’s largest field (70 MW) in 2010 in Italy. Its long history and international presence (covering India, China and the USA as well as Europe) makes Bonfiglioli a reliable and bankable investor. In 2011, Bonfiglioli contributed to the start-up of major installations in emerging markets, led by India and China.

Bonfiglioli solutions for solar energy

Bonfiglioli’s products for the PV sector include inverters for all applications, from compact, 30 kW devices to modular, turnkey, 1.6 MW solutions for indoor and outdoor installation.

The latest addition to the range, the RPS TL Modular Outdoor Series, offers superb weather resistance and flexible installability. Its all-new, modular design and the availability of 440 kWp, 660 kWp, 880 kWp and 1,110 kWp transformer cabins allow installations to be segmented as needed.

Bonfiglioli Riduttori S.p.A. Address: Via Giovanni XXIII, 7/A 40012 Lippo di Calderara di Reno – Bologna · Italy Phone: +39 0516473111 Fax: +39 0516473126 Email: photovoltaic@bonfiglioli.com Web: www.bonfiglioli.com Year founded: 1956 Employees: 2,800

Bonfiglioli inverters come with a warranty of up to 20 years, and can be controlled via the web from anywhere in the world.

Worldwide service ensures that customers enjoy rapid assistance by specialist personnel and means that Bonfiglioli solutions are specific, effective and long lasting.

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Business areas: PV generators, inverters, MLPM, connection technology, monitoring/supervision, power plant control

Shanghai Chint Power Systems Co., Ltd.

Danfoss Solar Inverters

One-Stop Solutions for PV Systems Shanghai Chint Power Systems, a solar power system solution provider, provides reliable, green and high efficiency PV inverters and electrical power solutions ranging from 1.5 kW to 1 MW. Our inverters reach a top efficiency of up to 98.5%.

Danfoss Solar Inverters – Smart Solutions We supply reliable, flexible and user friendly inverter solutions for residential, commercial and large-scale applications worldwide.

10 MW East Railway Station PV system in Hangzhou China. The Chint Group provided the overall solution.

Business areas: inverters, monitoring/supervision, software/IT

The TLX Pro series offers control of up to 100 inverters from a single selfdesignated inverter.

TLX Pro powers 80+ MW facility in Eggebek, Germany; one of the largest PV plants in the world

The inverter family from 1.5 kW to 500 kW

Shanghai Chint Power Systems Co.,LTD. Address: Block 4, 855 Wenhe Road Songjiang District, Shanghai 201614, China Phone: +86 21 37791222 Fax: +86 21 37791222-6003 Email: sales.cps@chint.com Web: www.chintpower.com Year founded: 2009 Employees: 260

PV system total solution provider including modules, inverters, system accessories, transformer etc.

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Shanghai Chint Power Systems is a solar power system solution provider. An international management team, global experience in research and development, strong financial support from the Chint Group and 27 years of manufacturing experience have made Chint Power Systems a well-known brand in the field of renewable energy.

in process in manufacturing and field tracking of operation. Product reliability is one of Chint Power’s highest goals.

Performance coupled with design March 2011. The CPS SC Series inverter won the German “red dot” top industrial design award, and thus became the first red dot award winner among inverter manufacturers in China. In the same year, CPS SC20KTL-O achieved two A grades in PHOTON’s lab test, with the report being published in the Nov 2011 issue of Photon international. The report praised the device as “… one of the top 10 inverters tested so far”.

One-stop solution Chint creates an enormous variety of electrical generation components including PV panels, inverters, switchgear, power transmission and distribution equipment, instruments and meters, and many more.

Chint Power Systems’ easy access to the entire Chint Group product portfolio al- Quality assurance worldwide lows us to provide and support tailored Chint Power System’s inverters are certiand complete systems solutions. fied by the German TÜV/VDE, the Italian ENEL2010, the Spanish RD1663, the British High reliability G59/G83, the Belgian C10/11, the North The high reliability of Chint Power pro- American CSA/ETL/FCC and the Chinese ducts is achieved by controlling every step Golden Sun standards, etc. of the product life-cycle. Chint Power Systems strictly follows the DFR (design for reliability) for component qualification, derating of components, reliability testing, and MTBF estimation in the design phase. Product reliability at the customer’s site is ensured by applying the burn-

Danfoss is a global company with over 40 years of experience in power electronics.

Danfoss Solar Inverters develops and manufactures a comprehensive range of gridconnectable, photovoltaic inverters for all PV applications, and is represented in more than 20 countries worldwide. The Danfoss inverter range (from 1.8 to 15 kW) provides the smart solutions needed to develop your PV set up.

Commercial solutions Designed to achieve the layout flexibility needed to maximize the energy yield of the area available – especially when encountering complex roofing challenges.

· The TLX series 3-phase transformerless inverter range from 6 to 15 kW. · The ULX series 1-phase transformerbased inverter range from 1.8 to 5.4 kW.

SmartTechnology With a powerful new suite of tools, including EnergySmart, DesignSmart, TrackSmart and ControlSmart, achieving maximum yield from your solar setup has never been easier. From planning and installation to trouble-shooting and service – in addition to having one of the industry’s most experienced solar support teams, Danfoss offers clean and efficient solar energy solutions for all applications.

Large-scale solutions Designed to reduce the effect of shading, allowing for more PV per m2, and closer placing of module rows.

Solutions for all PV system ranges Planning a PV system that reliably delivers maximum yield at minimum cost is possible with a Danfoss solar inverter solution. Whether you are designing a residential, commercial or large-scale power plant, a fully optimized system will raise the energy yield while lowering system costs. For a comprehensive overview of our products and services, please visit us at www.danfoss.com/solar.

Residential solutions The TLX Pro series offers inverter & webserver in one solution. Just one inverter is needed for installations up to 17 kWp.

Danfoss Solar Inverters A/S

Address: Ulsnaes 1

6300 Graasten · Denmark

Phone: +45 7488 1300

Email: solar-inverters@danfoss.com Web: www.danfoss.com/solar Year founded: 1933

Employees: 23,000 (worldwide)

Weighing only 35 kg, the TLX Pro inverter is easy to install and configure.

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Business area: lightning and overvoltage protection

Business areas: inverters, monitoring/supervision

DEHN + SÖHNE GmbH + Co. KG.

Diehl AKO

DEHN – Global Specialist in Lightning and Surge Protection Located in the Nuremberg Metropolitan Region, DEHN + SÖHNE is a globally active family-owned company specialized in the field of surge protection, lightning protection/earthing and safety equipment.

PLATINUM® – The Premium Brand for Solar Inverter Technology Diehl AKO, a company of the Diehl Group, is one of the world’s leading electronics companies. A long tradition and a guaranteed production volume in Germany alone of more than 20,000 electronics a day form the basis of an outstanding inverter technology. With conversion efficiencies of more than 98% PLATINUM inverters are among the best of their type.

Lightning protection systems and surge arresters to protect your investment

Manufacturing plant of PLATINUM inverters

DEHN + SÖHNE Neumarkt – headquarters and manufacturing plant

Diehl AKO headquarters in Wangen im Allgäu

Technologies for photovoltaic power generation made in Germany set the global trend. It is therefore no surprise that the most innovative products with regard to the safety of PV installations come from Germany.

DEHN + SÖHNE GmbH + Co. KG. Address: Hans-Dehn-Straße 1, Postfach 1640, 92306 Neumarkt · Germany Phone: +49 (0)9181 906-0 Fax: +49 (0)9181 906-1100 Email: info@dehn.de Web: www.dehn.de Year founded: 1910

Employees: 1,460 (DEHN Group)

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DEHN + SÖHNE is a leading provider of lightning and surge protection for PV systems.

For more than two decades DEHN + SÖHNE Test laboratory with globally unique performance parameters has been setting trends in this area of protection technology worldwide. From kilowatts to megawatts, DEHN + SÖHNE pro- of damage caused to protective devices tects your investment against faults and by installation or insulation faults in the PV circuit. It clearly reduces the danger of damage caused by lightning and surges. fire occurring as a result of an overloaded Based on decades of experience in apply- arrester, by putting it into a safe electrical ing surge protective devices in PV systems, state without disturbing the operating the DEHNguard® M YPV SCI surge arrester state of the PV installation. embodies the continuing progress and revDEHN + SÖHNE offers olution in device and system security. innovative lightning and surge protection products, protection concepts tailored to The proven DEHN + SÖHNE technology for fault-resistant Y protective circuits, and customer needs as well as engineering and patented combined disconnecting and testing services in the company’s impulse short-circuiting devices with Thermo Dy- current laboratory. Finding and taking new namic Control and an additional backup paths in lightning and surge protection has fuse, allow for safe and easy replacing of been the focus of the lightning and surge the protection modules in case of overload protection specialist DEHN + SÖHNE for without disconnection from supply. This more than 100 years. synergy of technologies reduces the risk

In addition to a wide range of string inverters with power ratings between 2 kW and 22 kW, the PLATINUM product portfolio includes smart devices for monitoring photovoltaic systems. The WebMaster Home is an excellent example of a smart energy regulation device. The convenient energy management solution visualizes and controls any number of consumers, and enables self-consumption to take place at optimum times of day.

Thanks to the patented DIVE® technology, PLATINUM inverters have a peak efficiency of 98% and are manufactured to the highest level of industrial quality. All inverters undergo an intensive, six-stage quality control test before leaving the factory.

PLATINUM inverters are therefore extremely robust and highly reliable. These characteristics, alongside an especially low failure rate make the PLATINUM products completely solid system components. As a result, Diehl AKO offers a 10-year warranty off works for the majority of its PLATINUM products and there is an option to extend the warranty up to 20 years. All PLATINUM inverters are also CE compliant and meet the corresponding appropriate standards.

Training sessions on all PLATINUM products are regularly held for distributors, sales representatives and installers in the training center at the company’s headquarters in Wangen im Allgäu. Furthermore, the PLATINUM service experts offer advice on designing and starting up monitoring solutions, as well as giving general support. They also quickly and competently help find solutions to complex situations over the phone or by sending a sales representative directly to the client on-site.

Diehl AKO Stiftung & Co. KG Address: Pfannerstraße 75 88239 Wangen · Germany Phone: +49 (0)7522 73-700 Fax: +49 (0)7522 73-710 Email: platinum@diehl-controls.com Web: www.diehl.com/photovoltaics Year founded: AKO founded 1945, Diehl AKO since 1994 Employees: 2,800 (worldwide)

The new PLATINUM R3 constantly evolving with peak efficiency

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Business areas: inverters, connection technology, monitoring/supervision

Business area: inverters

Emerson Solar Europe

Enphase Energy

Ten Mission-Critical Reasons to Bank on Emerson’s PV Inverters

Enphase Energy Enphase Energy has pioneered a new approach to managing solar power that makes solar systems smarter and more efficient.

The Enphase System consists of the Enphase Microinverter, Envoy Communications Gateway™ and Enlighten Software.

Emerson 1 MWp grid-tie inverter

A 660 kW site, utilizing almost 2,000 Enphase Microinverters across 99 dual axis trackers

Emerson’s multi-million euro UK R&D center

58 MWp solar plant, Avenal, California

1. The resources to deliver on our promises Emerson is a Fortune 500® corporation with outstanding bankability in the eyes of the financial community.

Emerson Solar Europe (HQ) Address: The Gro Newtown Powys SY16 3BE · United Kingdom Phone: +44 (0)1686 612900 Email: solar@emerson.com Web: www.emersonpvsolutions.com Emerson Solar Asia Address: 117 B Developed Plot Ind. Estate, Perungudi, Chennai, 600 096 · India Phone: +91 (0)44 2496-1123 Emerson Solar Americas Address: 7078 Shady Oak Road Eden Prairie, 55344 Minnesota · USA Phone: +1 952 995-8000 Employees: 127,000 (worldwide)

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6. Wherever you are, so are we Emerson employs more than 140,000 people, of which the majority are located within engineering centers around the world, providing project engineering and support for our energy conversion products.

2. Designed for long life Emerson uses standard mass-produced inverter modules that are used in both indus- 7. As much or as little as you need trial and PV applications. The modules have Emerson can provide as much or as little of a stable design that is proven to be robust. the PV inverter system as you need, from a single inverter to a complete solution in3. Higher efficiency, more of the time corporating string connection boxes, transEmerson PV inverters are efficient (> 98% formers, shelters, medium voltage switches Euro η), and because of our unique modular and SCADAs. inverter solution, we switch on sooner and off later, efficiently generating more energy 8. Complete peace of mind with lower irradiance levels than single in- Extended warranties and service contracts verter solutions. of up to 20 years are available to ensure the highest energy yield is maintained 4. Energized to meet your deadlines over the lifetime of the plant.

Emerson understands the time pressures associated with PV plant installations; our 9. Ready for PV industry growth project management teams work tirelessly Emerson is geared up to mass produce to ensure you meet your start-up deadlines. standard modules with high availability to support the growth of the PV industry.

5. Tolerant to faults Emerson inverters are fault-tolerant: In the 10. In service around the world event that an inverter module trips, the in- Emerson inverters and PV solutions are truly active module is automatically isolated so global in coverage. Large-scale projects like that the system can continue generating. our recent 58 MW DC solution in California System redundancy can also be specified. are being developed around the world.

Enphase Energy delivers microinverter technology for the solar industry that increases energy production, simplifies design and installation, improves system uptime and reliability, reduces fire safety risk and provides a platform for intelligent energy management.

and we bring a system-based, high technology approach to solar energy generation leveraging our design expertise across power electronics, semiconductors, networking, and embedded and web-based software technologies.

To date, the solar industry has relied on a traditional central inverter approach that has remained largely unchanged for the past two decades.

We have grown rapidly since our first commercial shipment in mid-2008, which amounted to more than 1.6 MW, representing over an estimated 40,000 solar installations.

We have built a semi-conductor-based microinverter system from the ground up that converts direct current (DC) electricity to alternating current (AC) electricity at the individual solar module level,

Given the significant advantages over traditional central inverters, we believe that microinverter solutions will become the standard for residential and commercial solar applications.

Enphase Energy Address: 201 1st Street Petaluma, California, 94952 · USA Phone: +1 877 797-4743 Email: info@enphaseenergy.com Web: www.enphase.com Year founded: 2006 Employees: 300

Enphase employs over 300 people in the USA, Italy, France, New Zealand and China.

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Fronius production site at Sattledt, Austria

Business area: inverters

Companies: xxx

Fronius Deutschland GmbH A Leader in Quality and Sustainability State-of-the-art technology in high-performance electronics, the use of high-capacity processors and the interconnection of stand-alone devices are the key to success for Fronius.

Assembly of the Fronius IG Plus inverters – optimal product quality ensured by highly sensitive screening tests

Fronius Deutschland GmbH

Address: Am Stockgraben 3

36119 Neuhof-Dorfborn · Germany

Phone: +49 (0)6655 91694-0 Fax: +49 (0)6655 91694-50

Email: pv-sales-germany@fronius.com Web: www.fronius.de Year founded: 1993 Employees: 220

Fronius IG Plus: reliable and multifunctionally applicable allround inverter

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Fronius PV inverters are tested under extreme conditions to meet quality requirements.

After a qualification training, Fronius Service Partners are able to replace PC boards by themselves.

Fronius, with its headquarters based in Austria, has been researching new technologies for converting electrical energy since 1945. That’s more than 60 years of experience, progress and continuous innovation. Fronius’ Solar Electronics division has been involved in photovoltaics since 1992 and sells its products through a global network of sales partners.

Producing and selling quality As a quality leader, Fronius’ Solar Electronics division develops and produces highperformance inverters for mains-connected solar power systems from 1 kW upwards.

The product range is complemented by an extensive range of components for professional system monitoring, data visualization and analysis – all available as standalone product add-ons.

In addition to its Solar Electronics division, Fronius is internationally successful in the fields of battery charging systems and welding technology. Outstanding products and services, such as the Fronius IG Plus series of inverters and the unique Fronius Service Partner program, make Fronius Solar Electronics a quality leader in the global market.

Living sustainably At Fronius, we live sustainably. Using renewable energy and protecting resources are important parts of the Fronius corporate culture. The company’s own photovoltaic system (PV system) in Sattledt lives up to this philosophy: It is one of the largest systems in Austria and has an output of 615 kWp (kilowatt peak) and a module area The German subsidiary – Fronius Deutsch- of 3,823 m2. Most of the power demand of land GmbH – was founded in 1993. Since the Fronius production and logistics site in 2006, its headquarters has been based in Sattledt is met by the site’s own PV system.

Neuhof, located in the middle of Germany.

There, all three divisions, Solar Electronics, Innovative products and new technologies Battery Charging Systems and Welding Efficient, reliable, high power inverters form Technology, are consolidated under one roof. the heart of any PV system. In the development of PV inverters, Fronius has thought out new technologies, searched for innovative solutions, and has found completely new answers. The result: highly functional

mains-connected inverters, which interact Reliability, efficiency and power optimally with all solar modules.

Fronius inverters are characterized by their extremely reliable, efficient and powerful Unique system design with the Fronius nature. Fronius uses the latest production MIXTM concept and testing methods to ensure that its Fronius’ flair for innovation is also reflected products are of the highest quality before in the innovative MIX™ concept, which they are shipped worldwide. obtains the maximum amount of energy from the sun to guarantee high yields, Fronius also places a great deal of emphasis even when the insolation level is low. This on user-friendliness and outstanding cusconcept is also a central part of the Fronius tomer service. The unique concept of conCL central inverter launched in 2010, which necting several devices makes installation contains up to 15 identical power stage sets. considerably easier. As evidence of this These power stage sets are switched on and concept, the connections and power stage off depending on the level of insolation and set compartments are fitted separately, alnumber of operating hours. This optimizes lowing the inverters to be installed quickly utilization levels and ensures maximum and easily. yield, especially under partial loads.

The Fronius Service Partner program Fronius also provides Fronius DATCOM, a The Fronius Service Partner program has set user-friendly data communications sys- itself the task of training installers to betem for individual PV system monitor- come passionate photovoltaics experts. The ing. The hardware components are quick program focuses on replacing PC boards. Foland easy to install, the software easy to lowing training, installers are able to replace operate. Because of its modular design, PC boards and other components of the PV Fronius DATCOM can be upgraded at any system quickly and easily without the need time. Customized monitoring solutions, to change the entire inverter. In addition, the from basic equipment to complete system Fronius Service Partner is supported by promanagement, can be installed easily. fessional sales and marketing services.

This partnership focuses on cooperation as a means to achieving success, in order to

deliver on reliability and quality as some of the most important purchasing criteria.

Fronius and the Fronius Service Partners know each other personally and maintain a cooperative relationship of mutual benefit.

Fronius CL: A modular system ensures maximum yield.

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Business areas: PV generators, inverters, monitoring/supervision, connection technology, software/IT, storage technologies

Business area: monitoring/supervision

KACO new energy GmbH

meteocontrol

The Right Inverters for Any Solar System Founded in 1998, KACO new energy is one of the most experienced and largest manufacturers of solar inverters in the world. The company’s vision is a power supply that comes from 100% renewable sources.

Independent Consulting and Intelligent Solutions for Your PV Project

A symbol for the energy turnaround: Industrial wasteland in Muldenstein, Germany, becomes an 11.2 MW solar park.

VIRTUAL CONTROL CENTER

METEOROLOGICAL DATA

PUBLIC NETWORK

DATA STATION

MODULE STRINGS 1 – 3

MODULE STRINGS 4 – 6

MODULE STRINGS 7 – 9 INVERTER

INTERNET

RIPPLE CONTROL RECEIVER

IRRADIATION

GENERATOR CONNECTION BOX

TEMPERATURE

METEOCONTROL SERVER

With large-scale systems or PV power plants in particular, monitoring must be optimally coordinated

ACTIVE AND REACTIVE POWER CONTROL

WIND

METEOROLOGICAL STATION

NETWORK PROVIDER

Powador 39.0 TL3: extremely flexible solution for decentralized PV systems up into the megawatt range

KACO new energy GmbH Address: Carl-Zeiss-Straße 1 74172 Neckarsulm · Germany Phone: +49 (0)7132 3818-0 Fax: +49 (0)7132 3818-703 Email: info@kaco-newenergy.de Web: www.kaco-newenergy.de Year founded: 1998 Employees: 850

Taking responsibility for a sustainable world: carbon-neutral production at KACO new energy in Neckarsulm, Germany

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The Powador product line from KACO new energy features solar inverters for every module type and system size – from singlefamily homes to megawatt solar parks.

The inverters are complex energy and grid managers that combine a wide range of functions in a very small unit. They form the heart of the PV system and make a substantial contribution to the control of renewable energies in the power supply system.

The latest developments include the learning energy storage and management system Powador-gridsave and the integrated solution Powador-microGrid for electrifying areas that are located far from the grid. A comprehensive range of equipment for monitoring PV systems completes the portfolio. KACO new energy has produced over four gigawatts of inverters since 1999.

Excellent service and exceptionally high quality standards form the basis of the company’s success. After all, sustainable yields and a quick return on investment are not possible without durable inverters. KACO new energy was the first manufacturer to offer a standard warranty lasting seven years.

A wide range of inverters for flexible system planning Thanks to an extensive product portfolio, you can find exactly what you need (the kW values refer to the maximum recommended generator power): · transformerless single-phase inverters from 3.2 to 9.6 kW · galvanically isolated single-phase inverters from 2 to 6 kW · transformerless three-phase inverters from 10 to 18 kW · transformerless three-phase inverters from 30 to 72 kW for residential as well as commercial use · galvanically isolated three-phase inverters with 16 and 18 kW · central inverters from 120 to 600 kW, respective stations upon request Country-specific settings allow the units to be used in all of the world’s important solar markets.

meteocontrol is a technological leader and has been one of the most innovative service providers in the solar energy sector for more than 30 years.

Dates and facts The company’s headquarters is in Augsburg, Germany; further offices are located in Moers, Germany, Milan, Italy, Madrid, Spain, and Lyon, France. Its sister company, meteocontrol North America, was set up in 2010 for the North American market. 100 employees now work at these sites.

Independent consulting The construction and operation of solar systems relies on high investments. The competence and experience of independent experts are indispensable in securing these investments and minimizing risks.

As a consultant and technical service provider, meteocontrol supports solar projects with technologically leading solutions throughout the entire project life-cycle, such as reliable forecasts which incorporate all relevant parameters and form the basis for sound and solid planning. An extensive range of services enables implementation and allows meteocontrol to ensure proper, planned commissioning for large-scale projects.

Competence in energy and weather meteocontrol is able to draw on the most modern information technology and years of experience in monitoring renewable systems: 24,000 solar systems with a total power of over 4.3 GWp are currently monitored. With a global market share of over 10% in professionally monitored systems, meteocontrol is a global market leader in this segment. meteocontrol’s product portfolio now offers monitoring solutions for every operation size – from private systems through to solar power plants.

The recording and analysis of highly valid solarization data from satellite measurements enables precise energy forecasts for PV systems. These solar power forecasts allow energy suppliers and network operators to precisely plan their network loads and solar share of the energy mix.

meteocontrol GmbH Address: Spicherer Straße 48 86157 Augsburg · Germany Phone: +49 (0)821 34666-0 Fax: +49 (0)821 34666-11 Email: info@meteocontrol.de Web: www.meteocontrol.de Year founded: 1976 Employees: 100

Intuitive and appealing design – the datalogger for monitoring your private PV system

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Business area: connection technology

Business area: inverters

KOSTAL KOSTAL – Intelligent Photovoltaic Solutions for Every Requirement As part of the KOSTAL group – a family-owned and internationally active company from Germany with 100 years of tradition – KOSTAL Industrial Electronics and its sales company KOSTAL Solar Electric for solar inverters offer comprehensive solutions in the field of photovoltaics. In this sector KOSTAL focusses on solar module connection technology and “PIKO” inverters.

PIKO Data Communicator

One PIKO for up to 30 countries

Fully automatable PV junction box SAMKO 100 04

Smart connections.

KOSTAL Industrie Elektrik GmbH (KOSTAL Industrial Electronics) Address: Lange Eck 11 58099 Hagen · Germany Phone: +49 (0)2331 8040-4800 Fax: +49 (0)2331 8040-4811 Email: info-industrie@kostal.com Web: www.kostal.com/industrie Year founded: 1995

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Hagen/Westphalia – home of KOSTAL Industrial Electronics

KOSTAL Industrial Electronics and KOSTAL Solar Electric – simply a smart connection The KOSTAL “Smart connections.” philosophy is based on four competitive advantages: KOSTAL family, real partnership, quality-offensive thinking and future programs. The interaction of these factors brings about smart connections between KOSTAL and its partners, as well as between the products and the product benefits.

These connections are designed to obtain success in the long run.

PV plug connector KSK 4

PV junction boxes – smart connections for solar modules KOSTAL Industrial Electronics is able to draw on the extensive experience in the development and production of solar module connection technology that it has been garnering since 1998. Taking into account the different customer requirements, the company has established a comprehensive portfolio of customer-specific and universally usable solutions. This wide array of products ranges from standard solutions to automatable options.

KOSTAL has developed innovative concepts for solar module connection technology, such as leadframe technology, and these have become firmly established in the market. To round off the product range, KOSTAL now offers PV plug connectors – a reliable solution for the whole PV system.

PV module connection technology from KOSTAL is always a smart connection – today, tomorrow and in the future.

The KOSTAL team – a strong partner

PIKO inverters: flexible, communicative, practical KOSTAL Solar Electric offers an extensive range of PIKO products in various power classes through to central inverters, with the emphasis on three-phase feed concepts even in the lower power classes. The high input voltage range and the independent MPP trackers in all of the PIKO inverters provide maximum flexibility in the field of application and simple handling.

All inverters in the KOSTAL PIKO range include a comprehensive communication system. Each PIKO has an integrated data logger which stores the data of the PV system for up to a year. Further communication options range from the provision and monitoring of all important data – with the aid of integrated interfaces – to the control of external devices. The PV system

can be monitored both locally and remotely using the PIKO Data Communicator for monitoring via digital picture frames, the web server, the PIKO Master Control, and the PIKO Solar Portal.

KOSTAL Solar Electric is expanding, and is pursuing a clear strategy with the focus on prime markets via local distribution companies. With subsidiaries in Spain, Italy, France and Greece, KOSTAL offers sales, service and training on site in the local language.

The KOSTAL seminars provide customers and partners with new perspectives by providing the latest information on gained experience and new developments. A proactive exchange of knowledge and information allows customers and partners to quickly and directly keep up-to-date with the latest developments.

KOSTAL Solar Electric GmbH Address: Hanferstraße 6 79108 Freiburg i. Br. · Germany Phone: +49 (0)761 47744-100 Fax: +49 (0)761 47744-111 Email: info-solar@kostal.com Web: www.kostal-solar-electric.com Year founded: 2006

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Business area: connection technology

Multi-Contact AG

Phoenix Contact GmbH & Co. KG

Efficient MC3 & MC4 PV Connectors. Rely on the Original!

In 2012, Multi-Contact celebrates its 50th anniversary. Founded in 1962 in Basle, Switzerland, the former family business has grown into one of the leading manufacturers of PV connector systems worldwide.

Comprehensive Solutions for Optimized PV Operation Phoenix Contact is the global market leader in components, systems and solutions for electrical engineering, electronics and automation.

An automation specialist, the company has become internationally established as a trusted partner to the PV manufacturing industry.

Multi-Contact’s competence center for photovoltaics in Essen, Germany

Business areas: connection technology, LOP, monitoring/supervision, software/IT

Solarcheck measuring modules measure current in up to eight strings as well as voltage.

Type of MC Multilam, based on the torsion spring principle

Sunclix enables uniform, cost-effective cabling from module to inverter.

PV connector MC4PLUS, designed for use in high volume cable assemblies

Multi-Contact AG

Address: Stockbrunnenrain 8–12

4123 Allschwil · Switzerland

Phone: +41 (0)61 306 55-55 Fax: +41 (0)61 306 55-56

Email: basel@multi-contact.com Web: www.multi-contact.com Year founded: 1962

Multi-Contact is a true pioneer in PV connectivity: In 1996, the company introduced the MC3, the world’s first PV connector in series production, followed by the MC4 in 2002. Since then, MC has developed a broad range of products for the PV industry, such as connectors, solar cables and junction boxes, providing complete cabling solutions from the panel to the inverter. The MC Multilam Technology ensures low contact resistance, minimal power loss, high corrosion resistance and long product life. Always aiming for the optimum approach, Multi-Contact specializes in customized solutions.

Multi-Contact’s new MC4PLUS connector comes pre-assembled with solar cables in cross sections of 1.5 mm2, 2.5 mm2, 4 mm2 and 6 mm2. The snap-in lock can only be opened with a special tool, ensuring maximum safety for the connection.

The MC4PLUS is IP65 and IP67 rated and is recognized by TÜV (1000/1500 V) and UL (600/1000 V). It has been designed for use in high volume cable assemblies. Today it is the first PV connector globally which fulfills this new requirement.

The Westlake junction box (PV-JB/WL) is available in 10A and 12A models and has been designed for use with connectors in the MC4 and MC3 series. It conforms to In an effort to limit both costs and time, protection category IP65 and is both TÜV the PV industry is calling for efficient, easy- and UL certified. The flat design of the box enables it to be installed directly underto-install solutions.

Multi-Contact answers this demand neath the module frame. without compromising quality by offering optimally harmonized products that are ready for use.

PV-JB/WL junction box for crystalline modules

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The family firm employs 12,300 staff worldwide and in 2011 generated sales of 1.52 billion euros. It has headquarters located in Blomberg (North Rhine-Westphalia) and Bad Pyrmont (Lower Saxony), with a total of seven companies belonging to the Phoenix Contact Group within Germany. In addition to its seven production sites, the international group has almost 50 sales branches as well as 30 representations throughout Europe and overseas. Within Germany, Phoenix Contact is represented by a nationwide network of approximately 80 sales engineers.

Protecting PV installations against lightning and power surges increases their availability, and is therefore a key aspect when planning new projects. Automated monitoring using small control systems provides users with a detailed overview of the output achieved by their plant at any given time. Special string measuring modules determine the quantities of solar power produced and forward this data to operators across the world via the GPRS network.

The portfolio of services is rounded off by a team of experienced specialists, With a product range that extends from which supports users around the world distribution and field connection points in all matters concerning the use of Phoewith special plug connector systems, nix Contact products. through PV measuring modules and signal transducers to automation technology – including comprehensive protection against lightning and power surges – the specialist automation company provides capable, reliable equipment for both PV generators and other systems. Products drawn from its comprehensive portfolio are used to realize all-inclusive solutions for optimized PV system operation.

Phoenix Contact GmbH & Co. KG Address: Flachsmarktstraße 8 32825 Blomberg · Germany Phone: +49 (0)5235-300 Fax: +49 (0)5235 341-200 Email: info@phoenixcontact.com Web: www.phoenixcontact.com Year founded: 1923

Sales volume: 1.52 billion euros

Employees: 12,300 (worldwide)

Each with two varistor arresters, surge protection devices offer dual resistance against failures.

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Business areas: inverters, monitoring/supervision

REFUsol GmbH

Santon Switchgear

High-Efficiency Inverters and Accessories for PV Installations REFUsol is a leading manufacturer of solar inverters.

With over 47 years of experience in power electronics, REFUsol is one of the top providers of solar inverters globally and one of the fastest growing companies in this field.

We Develop Switchgear Your Business Can Rely On With over 80 years of experience in developing DC switchgear, Santon Switchgear is an expert in the field of electromechanical safety switchgear for isolating PV installations.

Business areas: housing, LOP, connection technology

A small selection of loose switches, boxed switches and remotely operated switches

REFUsol central inverter at 70 MW PV plant in Germany

REFUsol string inverters at 4.6 MW PV installation in Belgium REFUsol training center in Metzingen

REFUsol GmbH

Address: Uracher Straße 91

72555 Metzingen · Germany

Phone: +49 (0)7123 969-0 Fax: +49 (0)7123 969-165 Email: info@refusol.com Web: www.refusol.com Year founded: 1965 Employees: 160

Our products As a central component in photovoltaic installations, solar inverters play a key role in energy conversion, ensuring profitability. Through our ongoing commitment to technical innovation, our inverters are leading the market when it comes to technology and efficiency, communication and monitoring as well as easy installation and scalability. Whether sold under the REFUsol brand or via an OEM, REFUsol products are ranked top in Photon efficiency factor tests.

Our company Our goal is to maximize the yield of our customers’ photovoltaic installations through our award-winning and cost-effective inverters – starting from small roof installations to larger solar power plants.

REFUsol is headquartered in Metzingen, Germany, and has international offices in Europe, Asia including China and India, and the USA, as well as sales and service partners in key strategic photovoltaic mar- Our high-quality product portfolio inkets around the world. cludes string, central and large inverters with a power range of 3.6 kW to 1.3 MW. Creative freedom and a passion for inno- Available globally, the range can be used vation are among our key corporate prin- in family homes as well as in large-scale ciples. REFUsol allows for creative space solar parks and is suitable for operation to drive superior engineering and our em- in extreme geographical and climaticallyployees are passionate about our products challenging environments, in an economic and the solar industry in general. and efficient way.

Using the right DC switchgear provides safety, whilst at the same time also contributing to increasing the lifetime of an installation. People working with DC current know the potential dangers of flame arcs and the damage they can do to an installation. Santon Switchgear is specialized in developing DC switchgear which can switch off DC current and isolate PV installations.

Proven DC switchgear Santon DC switches have been used in many industries all over the world for over 80 years and are known for their durability. With an extensive standard range and the ability to develop switchgear in line with its customers’ demands, Santon Switchgear is the perfect DC switchgear supplier for both installers and OEMs active within the renewable energy market.

Ready-to-install boxed switches The demand for boxed switches has grown over the last couple of years, both for residential and professional use.

Used materials need to be ready to use and easy to install in order to save time and costs. With products from 16 A – 1000 A and up to 1000 V DC and six poles, Santon offers a range which meets most of the market’s demands.

Standard boxed configurations include surge arrestors and spring terminals, and these will be expanded by an arc detection unit in early June 2012.

Santon GmbH Address: Bilsteinstraße 3 36041 Fulda · Germany Phone: +49 (0)661 952-9898 Fax: +49 (0)180 118-4199* Email: dach@santonswitchgear.com Web: www.santonswitchgear.com *3,9 cents/min from German landlines Year founded: around 1900

Customer specific solutions Developing solutions which meet specific demands is one of Santon Switchgear’s core competencies. Together with its cusThe ideal switch for OEMs tomers, Santon Switchgear develops soluWith a range from 16 A up to 1000 A and tions their businesses can rely on.

1000 V DC, Santon offers a wide selection of loose switches which meet the most Visit www.santonswitchgear.com for more common international standards. The information. modular design of the switches results in an endless variety of configurations, as The new well as very compact switches in relation Santon Arc to their performance. Santon switches are Detection Unit.

Available from therefore ideal for OEMs to work with.

June 2012

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Business areas: inverters, monitoring/supervision

Companies: xxx

RPS S.p.A. – AROS Solar Technology Division Italian Technological Expertise AROS Solar Technology is the expression of deeply rooted experience spanning more than 30 years in the power electronics industry.

AROS Solar Technology headquarters in Legnago (VR)

8.6 MW solar park in Sevilla, Spain (86 Sirio K100 units)

RPS S.p.A. AROS Solar Technology Division

Address: Via Somalia, 20

20032 Cormano · Italy

Phone: +39 02 663271 Fax: +39 02 6152049

Email: marketing@aros-solar.com Web: www.aros-solar.com Year founded: 1935

Employees: 600 (worldwide)

AROS Solar Technology is the solar division of RPS S.p.A., one of the companies belonging to the Riello Elettronica Group, a holding company since 1986, which works in the fields of energy, automation and security. The AROS Solar Technology division is the expression of deeply rooted experience spanning more than 30 years in the power electronics industry. The strength of always chasing the highest production standards and constantly anticipating market demands, together with sensitivity to saving energy and environmental protection, have allowed the company to apply its know-how to electronic energy management by developing systems for photovoltaic applications.

2006, in fact, saw the company’s debut in the renewable energy field with the introduction of its first range of inverters, immediately achieving excellent results and increasing its presence in the reference market. Over time, the range has been expanded and, thanks to recent corporate changes that have allowed efforts and investments to be concentrated solely on the photovoltaic sector, AROS Solar Technology can today offer a wide range of inverters that are increasingly complete and competitive, with power outputs ranging from 1.5 kW to 500 kW, in addition to complete monitoring solutions for all requirements, from small residential systems to solar power plants with capacities of several MW. At present the company employs about 600 people worldwide and has subsidiaries in Germany, Spain, France, the UK, China, India, Singapore and Australia.

Reliability and innovative technology The TL range of inverters guarantees very high quality power, operational flexibility and high conversion efficiency (up to 97%) thanks to its “transformerless” technology.

The absence of transformers allows reductions in dimensions and weight while the elimination of parts subject to mechanical wear increases reliability over time.

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For larger systems, AROS Solar Technology also offers a wide range of centralized inverters, from 12 to 500 kW. A whole series of measures, including the search algorithm for the maximum power point (MPPT), the standby function in the absence of sunlight, the use of fans at a controlled speed and the generous sizing of the transformer, enable high conversion efficiency and guarantee maximum yield.

To further increase the overall performance of the conversion system, reducing installation costs, particularly in large systems, AROS Solar Technology offers the Sirio Central Station (SCS). Thanks to this solution, Sirio inverters are connected to a single, medium voltage transformer and housed in vibrated reinforced concrete cabins, ensuring a longer life, better heat insulation and excellent resistance to weather and adverse environmental conditions.

SIRIO central inverters

SCS solutions have recently gained a new addition in the 1 MW Sirio Central Station which, by combining two Sirio HV-MT 500 kW models and a 1,000 kVA transformer in a single cabin on a surface area of just over 13 m2, makes it possible to optimize space and achieve a unique level of compactness for this level of power, which translates into substantial cost reductions.

The two Research & Development centers in Legnago and Cormano mean it is always possible to pursue the highest standards of production: The most advanced technologies make it possible to design inverters that interact intelligently with users, providing higher levels of performance and efficiency with low running costs and a more functional design, minimizing maintenance and integrating smoothly with the installation environments.

These products are destined to maintain and increase the reliability that has made AROS Solar Technology one of the Italian leaders in the field and enabled it to achieve DNV quality system certification (UNI EN ISO 9001/2008).

SIRIO EVO transformerless inverters

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Business areas: inverters, connection technology, housing, charge regulators, monitoring/supervision

Schneider Electric

SIEL S.p.A.

The Global Specialist in Energy Management Schneider Electric provides complete solutions from panel DC output to grid connection, including monitoring, supervision, servicing and maintenance for large PV power plants as well as for commercial and residential installations.

The International Energy Expert Customized project capability and continued product support – two key features of SIEL S.p.A.’s untiring international activity within the renewable energy field

78 MW power plant with saferay GmbH (Germany)

Business areas: inverters, monitoring/supervision, software/IT

SIEL’s headquarters in Trezzano Rosa, Milan

Solution for residential and small commercial buildings

Bagni di Tivoli’s installation

Schneider Electric offers the PV Box, a prewired equipment package for large PV power plants and large commercial rooftop solar installations.

Schneider Electric SA Address: 35 rue Joseph Monier 92506 Rueil-Malmaison · France Phone: +33 (1)14 1297-000 Fax: +33 (1)14 1297-100 Email:

renewableenergy@schneider-electric.com Web: www.schneider-electric.com Year founded: 1836

Sales volume: 22.4 billion euros (2011) Employees:

> 130,000

For the residential and commercial markets, Schneider Electric offers DC/AC kits and grid-connected, single-phase and three-phase inverters ranging from 2 kW to 30 kW. All inverters are easy to install and The PV Box is a complete solution for elec- service. Thanks to the company’s complete trical distribution, security, monitoring solutions, Schneider Electric is able to optiand control, available from one vendor. A mize the energy efficiency of installations.

PV Box includes solar inverters (ranging from 100 kW to 650 kW), DC combiner The Schneider Electric solution for offboxes, step-up transformers and a medi- grid and back-up installations includes um voltage switchgear housed in a prefab- inverter/chargers, charge controllers (with ricated building to allow quick field wiring or without MPPT tracking), DC/AC breakfrom both the solar arrays and the utility ers and related accessories. The inverter/ grid connection point. Other items can be charger has unsurpassed surge capacity to added to the package, including climate prevent drops during power surges. It can controls, security equipment, monitor- be configured for single and three-phase ing equipment and power metering, with installations up to 36 kW and allows dual operation and maintenance offerings also AC inputs for the grid and a generator. available.

For more information about Schneider Electric, please visit www.schneider-electric.com

Solution for large commercial and PV power plants

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The Italian company SIEL S.p.A. works inter- SIEL’s offering is able to satisfy every renationally in power protection and renew- quest in terms of power and usage, and is able energies supported by a range of ongoing maintenance services such as installations teleSIEL has been one of the main international management, multiannual maintenance producers of certified ISO 9001-2000 emer- agreements, specialized consulting, a gency power supply systems for public free-call help desk and the fast provision and private mission-critical applications of original spare parts from the company’s in financial, industrial, telecommunication many world subsidiaries. and healthcare settings, data centers and other organizations since 1983.

SIEL cooperates in many international projects on a regular basis, with 1 GW of In 2000, SIEL successfully approached SIAC SOLEIL inverters all over the world, the market of PV and wind energy with from Europe to Asia and Oceania. The next the extensive production of single-phase opening of a new site in the USA and reinverters, high-power solar three-phase cent capital increases – from 520,000 to inverters and wind turbine inverters under 1,500,000 euros are further steps in SIEL’s the company brands of SIAC SOLEIL and expansion.

SIAC WIND WAVE. SIEL’s green energy mission involves every SIEL’s product portfolio includes PV invert- aspect of company life, through to the ers for stand-alone, grid-connected and adoption of governance and social responhybrid applications, namely single-phase sibility criteria. inverters from 1.5 to 6 kWp, three-phase BT inverters from 10 to 500 kWp, three- www.sielups.com phase TL inverters from 80 to 500 kWp, PS500 and PS1000 power stations and the SIAC SOLEIL 10TL; last year SIEL presented Mr Glauco Pensini, SUNSIEL, the new range of PV solar invertAdministrator (left) ers specifically conceived for the American and Mr Enrico Pensini, SIEL’s President (right) market.

SIEL S.p.A. Address: Via Primo Maggio, 25 20060 Trezzano Rosa (MI) · Italy Phone: +39 02 909861 Fax: +39 02 90968490 Email: info@sielups.com Web: www.sielups.com Year founded: 1983

Sales volume: 55 milion euros Employees: 110

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Business areas: inverters, planning and grid integration, monitoring/supervision, software/IT

Close to the airport: Thunder Bay is one of three large-scale PV power plants in Eastern Canada

Siemens AG Industry Sector, Industry Automation Address: Würzburger Straße 121 90766 Fürth · Germany Phone: +49 (0)911 750-0 Fax: +49 (0)911 750-2246 Email: sinvert.automation@siemens.com Web: www.siemens.de/sinvert Energy Sector, Solar & Hydro Division Address: Otto-Hahn-Ring 6, Gebäude 29, 5. Flur, 81739 München · Germany Phone: +49 0180 524 7000* Fax: +49 0180 524 24 71* Email: support.energy@siemens.com Web: www.siemens.com/pv

Siemens AG

Companies: xxx

Siemens Photovoltaic Solutions for Today and Tomorrow Siemens covers the entire PV value chain: from glass and silicon materials to module production, field installation, inverters, integrated automation systems and as a supplier of turnkey large-scale PV arrays.

We shape a green and sustainable environment for future generations Siemens is a global powerhouse in electronics and electrical engineering, operating in the fields of industry, energy and healthcare as well as providing infrastructure solutions, primarily for cities and metropolitan areas. For over 160 years, Siemens has stood for technological excellence, innovation, quality, reliability and internationality. The company is the world’s largest provider of environmental technologies. Around 40% of its total revenue stems from green products and solutions.

At the end of September 2011, Siemens had around 360,000 employees worldwide, based on continuing operations.

* 14 cents/min from German landlines, prices for cell phone networks may vary Year founded: 1836

Employees: 360, 000

The plant in Fontebella, Italy, has a size of 5 MWp.

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The solar park in Les Mées, France, 31 MWp, provides electricity for more than 12,000 households.

Utility-scale photovoltaic power plants Siemens is actively engaged in the fields of Engineering, Planning and Commissioning (EPC) utility-scale photovoltaic power plants. As a general contractor, Siemens provides its customers with large-scale rooftop and ground-mounted arrays. The focus here is on customized solutions and overall optimization of the photovoltaic plants, with the goal of achieving the lowest power generation costs with the greatest degree of safety, reliability and return.

For the turnkey installation of PV power plants, Siemens supplies in-house manufacturing components such as inverters, transformers and medium-voltage switchgears, and combines these with PV modules from bankable suppliers and products from local markets. In addition, Siemens also offers a unique layout planning system for utility-scale PV power plants in its portfolio: It combines specific plant requirements with Levelized Cost of Electricity (LCoE)-optimized concepts.

SINVERT PVM inverters are available in the range from 10 to 20 kW for small to medium-sized plants in the “commercial” market segment. The three-phase inverter series is characterized by its compact design, its robust quality and its long service life.

The first ground based multi MW PV plant in Israel: Ketura

Applying a contract model in which the Performance Ratio (PR) is anchored, the efficiency and defined performance data of a solar plant can be guaranteed over the entire life-cycle of the plant.

Maintenance and feasible solutions for solid financing are services that round out the Siemens portfolio. A selection of different service packages is available for the operational phase. Particularly worth mentioning is the performance ratio guarantee, which minimizes financial risk for the plant operator and investors. In conclusion, Siemens offers technically optimized plant designs with only best in class products to guarantee the highest plant performance while safeguarding the customers’ investments over the whole lifetime of the plant.

SINVERT – photovoltaic inverters from Siemens With their high level of availability and optimized efficiency, SINVERT inverters provide a reliable basis for operating a photovoltaic plant efficiently throughout its entire lifecycle. SIEMENS PV inverters, with their peak efficiency of > 98%, are available for a broad market spectrum (commercial and power plants). The functions and yield of the entire photovoltaic plant can be monitored and visualized in a user-friendly fashion using SINVERT WebMonitor or SIMATIC WinCC industrial software. Complimentary SINVERT Select layout software is available for determining the optimum configuration for a PV plant.

The SINVERT inverter family PVM and PVS

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Business areas: PV generators, connection technology, planning and grid integration, monitoring/supervision, power plant control, software/IT, communication services

SMA Solar Technology AG

Continuity since 1977 – 35 Years of Pioneering Spirit Monitoring, control and supervision of photovoltaic power plants – Secure your investment and optimize your profit with skytron’s monitoring solutions

Energy that Changes SMA Solar Technology works actively to shape the worldwide change of the energy system and is the only inverter manufacturer that has pre-designed solutions to meet the challenges of the future.

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Sunny Tripower 20000TL-HE: SMA is the first to reach 99% maximum efficiency for standard equipment.

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03

SMA Solar Academy: a training center with an off-grid energy supply using renewable energy sources

PVGuard® SUPERVISION PLATFORM

SUPERVISORY LEVEL

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04

skytron® energy GmbH

Business areas: inverters, monitoring/supervision, software/IT

ETHERNET PLANT NETWORK

skylog© LOCAL DATA LOGGER

skylog© outdoor LOCAL DATA LOGGER

skylog© LOCAL DATA LOGGER

ACQUISITION 02 DATA LEVEL

skylog© CANOPEN FIELDBUS

POWER GENERATION

01

SENSOR LEVEL

ArrayGuard® COMBINER BOX

FIELDBUS

StringGuard® CURRENT + VOLTAGE

skyCONNi PYRANO

skyCONNi TEMPERATURE

STRING INVERTER

POWER GENERATION

°F °C

skyCONNi WEATHER

skyCONNi TRACKING

skyCONNi RADIATION

ArrayGuard® StringGuard® skyCONNi®

01 SENSOR

02 DATA ACQUISITION

03 CONTROL

04 SUPERVISORY

Field data measurement / String current monitoring / String protection / Condition monitoring / DC distribution / Safety remote OFF

On-site logging of all plant, control and gridinjection data / Data preprocessing / Broadband data transmission to long-term data hosting / Condition monitoring

Closed-loop plant control / Network analysis with actual value feedback / Metering / Interfacing and protection

Control room for remote plant supervision / Alarm handling and notification / Remote service management / Plant performance analysis / Monthly reporting / Comparison with yield assessment report

skytron® energy GmbH

Address: Ernst-Augustin-Straße 12

12489 Berlin · Germany Phone: +49 (0)30 688 3159-0 Fax: +49 (0)30 688 3159-99 Email: info@skytron-energy.com Web: www.skytron-energy.com

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The merger of skytron® energy with Wuseltronik, a 1977 spin-off of Berlin Technical University, has evolved into three decades of unique expertise in the use of solar energy. It is not without reason that we pride ourselves in being “pioneers of energy”.

From string current monitoring in the generator field to supervisory control room services allowing remote supervision of photovoltaic installations – skytron’s solutions are independent of the module and inverter technology used.

Pioneering spirit, continuity and longstanding experience, all combined with our vision for trendsetting power plant technology – this is our motivating force, driving the development of our integrated monitoring and control system for photovoltaic power plants.

Our innovations are your benefit:

Today installed all over the world in utilityscale solar installations, skytron’s control system meets the criteria for grid stability and security. It ensures dynamic adjustment of the feed-in power in response to the grid operator’s demand.

· multi-site multi-vendor SCADA

· high-precision PV string current measurement · sensorics for ambient condition measurement · intelligent DC combiner boxes

· real-time high-resolution data logging

SMA’s innovative technologies make a crucial contribution to grid integration and energy management, the enhancement of self-consumption and system cost reduction. The market and technology leader offers solar inverters for any module type and power class, as well as grid-connected PV plants, island or backup systems worldwide. SMA monitoring systems complete this comprehensive range of products. One of the latest product innovations is the Sunny Tripower 20000TL-HE. With this device, SMA is the first manufacturer to reach a maximum efficiency of 99% for standard equipment. The inverter preferred for large-scale installations is the Sunny Central 800CP, which offers top performance while requiring little space.

With the worldwide change of the energy system, comprehensive energy management at the household level, the incorporation of solar radiation forecasts, and the use of local storage systems are gaining more and more importance, paving the way to the intelligent “smart grid” and the “smart home”. With the Sunny Home Manager, the collaboration with PV forecast services, and the advancement of the proven Sunny Backup system for a gridconnected storage solution, SMA provides solutions to these future challenges.

SMA is headquartered in Niestetal/Kassel, Germany, and is represented in 19 countries on four continents. Due to its flexible and scalable production, SMA is in a position to quickly respond to customer demands and promptly implement product innovations.

Moreover, SMA provides a unique service with 85 service hubs worldwide, serving our customers even in remote regions.

SMA Solar Technology AG Address: Sonnenallee 1 34266 Niestetal · Germany Phone: +49 (0)561 9522-0 Fax: +49 (0)561 9522-100 Email: info@SMA.de Web: www.SMA.de Year founded: 1981

Sales volume: 1.7 billion euros (2011)

Employees:

> 5,300

· life-cycle long-term plant data management and analysis · control room facilities · complete life-cycle O & M

Self-consumption: Sunny Home Manager provides intelligent energy management at the household level.

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Companies: xxx

SolarMax Swiss Quality by Sputnik Engineering With its SolarMax brand, Sputnik Engineering AG has focused on solar energy since 1991 and has been a pioneer in the industry ever since.

Founded in the Swiss town of Biel, the company develops, produces and sells grid-connected inverters for every solar system.

Swiss quality with high efficiency: SolarMax inverters set standards in terms of quality, reliability, and maximum yields.

Sputnik Engineering AG Address: Höheweg 85 2502 Biel/Bienne · Switzerland Phone: +41 32 346 56 00 Fax: +41 32 346 56 09 Email: info@solarmax.com Web: www.solarmax.com Year founded: 1991

Employees: 360 (2011)

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High-quality products made in Switzerland have enabled SolarMax to grow from a start-up into one of Europe’s leading inverter manufacturers in an astonishingly short space of time. At present, the company has some 360 employees at its Swiss headquarters and at locations in Germany, Spain, Italy, France, China, Belgium, Great Britain, Greece, Bulgaria and the Czech Republic.

Thanks to technical know-how, broadly supported knowledge, and more than 20 years of experience in developing inverters SolarMax is able to produce high-quality products. SolarMax inverters are among the industry’s best, offering high efficiency, an intelligent cooling concept, an attractive, easily-mounted casing and a userfriendly graphics display. SolarMax has the right inverter for every application – from photovoltaic systems on single-family homes whose kilowatt output is modest, to the solar power plants whose output is measured in megawatts. Furthermore, the product family comprises a series of communication and monitoring solutions, as well as software tools developed for specific assignments. All inverters are extremely robust and absolutely reliable – and at a convincing price/performance ratio.

Each individual SolarMax inverter manufactured in Biel is put to the acid test upon completion, with a full load test of several hours, amongst others. This way, we are able to guarantee that each device meets the requirements for Swiss quality work.

Extendable service agreements ensure ideal planning security of up to 25 years.

This way we offer our customers quality and safety at the same time.

Service at its very best SolarMax customers who call the technical help line obtain advice from highly qualified technicians. The service team finds and eliminates errors by remote diagnosis or by sending a technician to the site. Retailers, wholesalers, electricians and operators of solar plants benefit from courses and training sessions designed by SolarMax for their own products and provided either at the company’s headquarters, at one of its branches, or directly at the customer’s premises. The SolarMax experts are always available for their customers with advice and support.

All requests are answered rapidly, frankly and directly, because SolarMax believes in solid customer service and long-term customer relations.

Coping with enormous challenges: The highest grid-connected solar power station in Europe on the Jungfraujoch in Switzerland runs with SolarMax inverters. (above)

Highly qualified technicians are on hand to advise SolarMax customers on the phone.

SolarMax offers system solutions for all requirements.

S series 2–5 kW

MT series 10–15 kW

C-/S series 20–35 kW

TS series 50–300 kW

TS-SV 330 kW

Power Station 330 kW – 1.3 MW

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Business areas: inverters, storage technology

Solutronic

Steca Elektronik GmbH

Inverters and Intelligent Systems for Greater Efficiency Solutronic is one of the leading suppliers of top-quality, cutting-edge, grid-connected inverters for photovoltaic installations and system solutions.

Steca Solar Electronics – Products and Solutions for an Ecological Future As a leading supplier of products for the solar electronics industry, Steca sets the international standard for the regulation and control of solar energy systems.

The management board, Michael, Dietmar and Peter Voigtsberger (from left)

SOLPLUS 55 inverter on the production line

SOL-Energymanager energy storage and management system

SOLUTRONIC AG Address: Küferstraße 18 73257 Köngen · Germany Phone: +49 (0)7024 96128-0 Fax: +49 (0)7024 96128-50 Email: info@solutronic.de Web: www.solutronic.de Year founded: 2004 Employees: 45

Steca PI-Set – parallel connection made easy: Steca Solarix PI inverters with outputs of up to 4,400 W

Solutronic inverters, which cover nominal AC power ratings from 1.5 to 12 kW, are software-controlled and therefore facilitate innovative monitoring and communications functions. Furthermore, they feature high efficiency levels of up to 98% and extremely low failure rates. Other key differentiators of SOLPLUS inverters are their great flexibility, extensive basic specs and, to reiterate, their intelligent communications options.

In tandem with its inverters, Solutronic also develops system solutions that enhance the efficiency of PV installations and utilize the electricity generated decentrally. As a result, the inverter no longer simply has the task of converting the direct current generated by the solar modules into alternating current for the grid, but must also ensure the effectiveness and efficient use of the power generated.

Here are two more new developments from Solutronic: Energy management with SOLPLUS inverters The latest SOLPLUS firmware makes it possible to manage the energy generated by the PV system intelligently without the need for additional, elaborate equipment.

An S0 meter measures in-house consumption levels and patterns, while the SOLPLUS+ evaluation software supplied for free provides the necessary graphics.

SOL-Energymanager energy storage and control system The SOL-Energymanager is a system designed specifically for households with an annual electricity requirement of up to 6,000 kWh and enables its owners to store and use their self-generated PV electricity effectively and economically. The device is a combination of a solar inverter, battery inverter, energy management system and a lithium-ion battery. The compact unit requires no complex, standalone pieces of equipment and is ready to use immediately after installation.

SOLPLUS 120 inverters in operation

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Business areas: inverters, storage technology, charge regulators, monitoring/supervision, software/IT, communication services

In the three market segments, PV grid connected, PV off grid and solar thermal, the Steca brand is synonymous with innovation and vision. Be it conception, development, production or marketing, we are committed to the highest quality standards. Our focus lies on made-to-measure solutions for the effective utilization of solar radiation. Furthermore, Steca continually examines the technologies it has Electronics made in Memmingen – Bavaria developed with a view to simple operation and, consequently, usability for the wide PV off grid Two billion people in rural areas still have base of the population – worldwide. no access to an electricity grid. Steca has set itself the target of improving the qualPV grid connected Together with our range of accessories, ity of life of these people. To this end, Steca StecaGrid inverters represent an innova- develops and manufactures top quality tive family of inverter solutions for grid products, which, thanks to their long lifeconnected solar power systems. Whether time, ensure extremely low costs. Today, being used in a small solar power system modern and professional electricity supfor a single family house, or an elaborate plies are necessary in every part of the combined solution for an industrial com- world. For these supplies, the focus is on plex, Steca grid-feeding inverters all have high industrial demands, flexibility, envione thing in common: They offer the high- ronmental sustainability and reliability. As est performance along with maximum an expanding company, Steca Elektronik will continue to bank on Germany and Baflexibility and ease of use. varia as an energy industry center: With a total of 650 employees, the company currently manufactures products for an ecological future on a production area of 29,000 m2.

Steca Elektronik GmbH Address: Mammostraße 1 87700 Memmingen · Germany Phone: +49 (0)8331 8558-0 Fax: +49 (0)8331 8558-132 Email: info@stecasolar.com Web: www.steca.com Year founded: 1976 Employees: 650

StecaGrid 3000 and StecaGrid 3600 have set a new world record in inverter efficiency.

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Business areas: inverters, charge regulators, planning and grid integration, monitoring/supervision, software/IT, communication services

Business areas: inverters, connection technology, storage technology, LOP, charge regulators, planning and grid integration, monitoring/supervision, power plant control, software/IT, communication services

Sungrow

Woodward IDS

The Largest PV Inverter Supplier in Asia In 2011, Sungrow Power Supply Co., LTD occupied around 40% of China’s PV inverter market share and had a cumulative installation capacity of 1.5 GW globally, with 400 MW installed in Europe.

Enhancing global quality of life and sustainability, by optimizing energy use through improved efficiency and lower emissions

3.6 MW PV plant, Milan, Italy

SOLO1000 solar inverter, 2MPPT with D-Booster technology

Sungrow manufacturing shop

Sungrow Headquarters Address: No.2, Tianhu Road, New and High Technology Industrial Development Zone, Hefei, Anhui · China 230088 Sungrow Business Hotline:

Phone: +86 551 532 7834/7845 Fax: +86 551 532 7856

Email: info@sungrow.cn

Web: www.sungrowpower.com

Sungrow France Address: 27, Avenue de l’Opera, 75001, Paris · France Phone: +33 17038 5270 Email: france@sungrowpower.com Web: www.sungrowpower.com Sungrow Germany

Address: Balanstraße 59

81541 München · Germany

Phone: +49 8962 8388 64

Email: germany@sungrowpower.com Web: www.sungrowpower.com

Established in 1997, Sungrow specializes in developing and manufacturing PV inverters and related equipment, as well as providing project consultation, system design, technical support, etc. After a successful IPO (November 7, 2011, Shenzhen, China), Sungrow became the leading public company in China’s renewable energy power supply industry. The +200 million USD capital raised by Sungrow makes a solid foundation for our future growth.

For the European market in 2012, we are preparing the SG10KTL/15KTL/20KTL/30KTL series for commercial applications, which meets both the requirements of the German BDEW Medium Voltage Directive and the VDE-AR-N 4105 Low Voltage Directive.

In addition to their embedded DC switches, double MPP trackers and weather-proof design (IP65) for tough working environments, the maximum efficiency of this series can reach 98%. Sungrow is also introducing the SG500MX and SG1000TS for its Sungrow is experienced in extreme power utility-scale PV inverter customers. grid situations and environmental conditions, and products in the SunAccess series Sungrow provides high-quality and lowhave showed excellent performance in the cost products as well as thorough and exworld’s highest PV plant located at an alti- cellent services, such as service hotlines tude of 4,300 m in Yangbajain, Tibet. Our and quick responses: Our dedicated team central inverters successfully passed multi- of engineers provides 24/7 support and ple LVRT tests, and have gained certification promptly responds to customers on all from TÜV and Enel-GUIDA. They are widely matters regarding installation, mainteused in Italy, France, Belgium, Germany, nance and trouble-shooting.

Australia, Canada, South Korea, etc.

Sungrow has already been identified as a Famous Trademark of China, and is listed in the Top 9 of Chinese Public Companies with the Greatest Potential by Forbes (2012).

Year founded: 1997

Sungrow worldwide: China, France, Germany, Canada…

Employees: approx. 800 SG1000TS, SG500MX, SG10~20KTL

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Innovative power electronics systems Woodward IDS, formerly known as Integral Drive Systems AG, is a leading provider of innovative power electronic systems, predominantly for utility- and commercial-scale photovoltaic power plants and wind turbines. Additionally, Woodward IDS offers power electronics solutions for power distribution, energy storage, and marine propulsion applications.

SOLO inverters feature a local color touch screen interface that provides a configurable display of electric power production, built-in diagnostic functions and data-logger readout of important data.

Strong global presence Woodward IDS is a subsidiary of Woodward, Inc., a financially strong, global organization that has been providing innovative technology to the energy markets Compact, high-efficiency inverter since 1870. With its outstanding reputatechnologies tion, global presence, and strong technoThe company’s “SOLO” series of solar in- logy background, Woodward is an ideal verters has been proven in hundreds of partner for long-term business relationphotovoltaic (PV) solar installations. SOLO ships. inverters are designed to maximize the power output from a solar array based Ready for the future on current switching, liquid cooling and Committed to quality and continuously maximum power point tracking (MPPT) developing new technologies – such as technologies. new inverter topologies that increase reliability and efficiency, and working SOLO inverters are available in output rat- with higher DC and AC voltages – ings of 100, 250, 500, and now 1,000 kW Woodward IDS offers a substantial cost using exclusive D-Booster technology (pat- advantage compared to conventional ent pending). All models are available for solutions. indoor (IP54) or outdoor (IP55) installation.

Extended-temperature-range (from – 25 °C to +55 °C) and high-altitude (up to 3,500 meters) configurations are available.

Woodward IDS Switzerland AG

Address: Hagenholzstraße 71

8050 Zurich · Switzerland

Phone: +41 445620600 Fax: +41 445620606

Email: Moreno.Bariffi@woodward.com Web: www.woodward.com Year founded: 1870

Sales volume: 1.7 billion USD Employees: 6,200

SOLO250 solar inverter with 3MPPT

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The Publishers

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Business area: communication services

Business area: communication services

Solarpraxis AG

Sunbeam GmbH

Engineering, Conferences and Publishing for Renewable Energies The Berlin-based company has been providing clients with expertise and professional services in the fields of engineering, conference organization and publishing since 1998.

Communications for the Renewable Energy Market Sunbeam offers technically oriented communication services perfectly tailored to the dynamic environment of the European renewables energy market.

Solarenergie in Deutschland Solar Energy in Germany

2011 2012 ■

Solarwärme Informationen für Vermieter

Drei Jahre Bundesverband Solarwirtschaft

engineering the solar age

Solar – so heizt man heute

Suppliers for Photovoltaics

The engineering department generates up-to-the-minute knowledge.

Solarpraxis’ conferences are valued industry platforms.

Year founded: 1998

Sales volume: > 5.9 million euros Employees: 60

Industry representatives are given the opportunity to share ideas, to follow and discuss the latest developments, and to meet representatives from politics, the press and the financial world.

Engineering The engineering department of Solarpraxis generates up-to-the-minute knowledge and processes it for your customers using a targeted and project-orientated approach, operating in areas such as expert opinion reports, training, technical hotlines, technical documentation and planning for solar installations.

Conferences Solarpraxis’ conferences are valued industry platforms, which offer decision-makers in the renewable energy industry opportunities for targeted networking and information exchange. They are well-established, close to the market and customer-oriented.

Using a combination of specialist presentations and topical panel discussions, they present practical knowledge relating to market development, financing and policies.

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Sunbeam combines high-quality communication services with expertise in technologies and markets in the field of renewables.

Solarpraxis communicates expertise and practical knowledge to professionals.

Solarpraxis AG Address: Zinnowitzer Straße 1 10115 Berlin · Germany Phone: +49 (0)30 7262 96-300 Fax: +49 (0)30 7262 96-309 Email: info@solarpraxis.de Web: www.solarpraxis.de

Publishing Solarpraxis AG offers a wide range of trade magazines and industry guides dedicated to renewable energies, and addressing professionals in the manufacturing and installation sector.

The B2B magazines “photovoltaik” (German edition, with Alfons W. Gentner Verlag) and “pv magazine” (global and Chinese edition) publish monthly or quarterly technology-focused reporting that covers the latest trends and market developments in the field of photovoltaics.

Generally in collaboration with the relevant technical associations, Solarpraxis AG publishes multilingual industry guides for various sectors of the renewable energy industry. These provide companies with the opportunity to present their products and services. An editorial section sets out the essential facts and figures relating to each sector plus the latest technological and economic developments.

Since 1998, Sunbeam has been providing in-depth market knowledge and excellent contacts with industry associations and the media. We offer our expertise in the following domain areas: Communications With over ten years of experience in renewable energy, Sunbeam has acquired expertise in all relevant technologies as well as an extensive media network in the field. The company has successfully conducted a variety of campaigns for governmental departments and offers a wide spectrum of services to corporate clients, ranging from PR concepts and consultancy to the complete management of all press contacts.

New media Sunbeam is one of the leading German agencies for information-oriented, accessible websites. The agency has won a prestigious BIENE award and ranks top in relevant listings for the content management system TYPO3. Two team members are also the authors of renowned specialist books on the design and implementation of web presentations.

Design Sunbeam values visual communications as a key success factor in the renewable energy market, and thus offers comprehensive expertise in presenting complex matters to technically oriented target groups. In our work for companies, associations and governmental departments we specialize in editorial design for periodical magazines, high quality brochures and extensive industry guides.

Added value Sunbeam operates through all media channels connected to public relations, new media and design. Clients benefit from our experience both in the management of individual formats and the creation of integrated marketing solutions.

Examples of this cross-media approach include our widely distributed press reports on solar, wind and bioenergy (“PresseTrend”) and various services for print to web and/or social media publishing.

Sunbeam GmbH Address: Zinnowitzer Straße 1 10115 Berlin · Germany Phone: +49 (0)30 72 62 96 - 300 Fax: +49 (0)30 72 62 96 - 309 Email: info@sunbeam-berlin.de Web: www.sunbeam-berlin.de Year founded: 1998

Sales volume: 1.4 million euros

Employees: 19

As full-service partner we support you managing your cross-media communications.

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Companies: xxx

Important Notice, Picture Credits, Legal Information, Sources IHS iSuppli — Important notice

This brochure, all parts thereof and the website are protected by copyright.

The reproduction, alteration and any other type of use of the brochure or parts thereof, except for purely private purposes, is prohibited except with the prior approval of Solarpraxis AG. This shall apply in particular to reproduction/copies, translations, microfilming and storage in electronic systems.

The citing of text by media representatives and political decision-makers is expressly desired and does not require prior approval, provided that the source of any text used is also cited.

“The Industry” sources

DGS Landesverband Berlin-Brandenburg: Leitfaden Photovoltaische Anlagen, 4. Auflage, Berlin 2010 Konrad Mertens: Photovoltaik, Carl Hanser Verlag, 1. Auflage, München 2011 photovoltaik 09/2011 photovoltaik 01/2012 Volker Quaschning: Regenerative Energiesysteme, Carl Hanser Verlag, 5. Auflage, München 2007

The illustrations printed in the company profiles were supplied by the respective companies. All other photos were created

by Tom Baerwald, with the exception of: Cover front small images, right REFUsol GmbH Cover back Siemens AG p. 8 Siemens AG p. 9 top PHOENIX CONTACT Deutschland GmbH p. 9 bottom left Danfoss GmbH p. 9 bottom left Steca Elektronik GmbH p. 10 SonnenPlus GmbH p. 11 Conergy Deutschland GmbH p. 14 Conergy Deutschland GmbH p. 15 small SMA Solar Technology AG p. 17 f. l. t. r. COLEXON Energy AG, Conergy Deutschland GmbH, Siemens AG p. 18 PHOENIX CONTACT Deutschland GmbH p. 19 Danfoss GmbH p. 20/21 f. l. t. r. Sputnik Engineering AG, SMA Solar Technology AG, Danfoss GmbH, REFUsol GmbH p. 22 REFUsol GmbH p. 24 large Sputnik Engineering AG p. 24 small SMA Solar Technology AG p. 25 top REFUsol GmbH p. 25 bottom right SMA Solar Technology AG p. 26 Siemens AG p. 27 bottom Danfoss GmbH p. 28 bottom COLEXON Energy AG p. 29 bottom right Gehrlicher Solar AG p. 31 top Suntech Power p. 31 bottom left Puget Sound Energy p. 31 bottom right USAF p. 32 top Puget Sound Energy p. 32 bottom Puget Sound Energy p. 33, p. 34 large Tom Baerwald/skytron® energy GmbH p. 34 small SMA Solar Technology AG p. 35 top Fronius International GmbH p. 35 bottom Tom Baerwald/skytron® energy GmbH p. 36/37 SonnenPlus GmbH p. 39 DEHN + SOEHNE GmbH + Co. KG p. 40 Michael Streib – Sachverständiger p. 41 top OBO BETTERMANN GmbH & Co. KG p. 41 bottom Weidmüller GmbH & Co. KG p. 42 Tom Baerwald/Globalsolar p. 43 top/bottom left Multi-Contact AG p. 43 bottom right Tom Baerwald/Globalsolar p. 44 top PHOENIX CONTACT GmbH & Co. KG p. 44 right Multi-Contact AG p. 45 Tom Baerwald/BAE Batterien GmbH p. 46 Tom Baerwald/BAE Batterien GmbH p. 47 top Tom Baerwald/BAE Batterien GmbH p. 47 bottom Fraunhofer-Institut für Chemische Technologie ICT p. 48 top voltwerk electronics GmbH p. 48 bottom Younicos AG p. 50 bottom right fotolia/© Alterfalter p. 51 top Hager Vertriebsgesellschaft mbH & Co. KG p. 51 bottom HUF HAUS GmbH u. Co. KG

Infographics and tables: © Solarpraxis AG unless otherwise stated

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The Global Leader in PV Market Research

Legal information Published by

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Covering the topics critical to your business:

Phone: + 49 (0)30 72 62 96 - 300 Fax: + 49 (0)30 72 62 96 - 309 Email: info@solarpraxis.de Web: www.solarpraxis.de

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Responsible under the German Press Act:

Karl-Heinz Remmers

© 2012 Solarpraxis AG Idea and concept

Solarpraxis AG Project management

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The texts and illustrations in this brochure were produced with the greatest possible care and to the best of the author’s knowledge. As errors cannot be ruled out and both texts and illustrations are subject to change, we draw your attention to the following: Solarpraxis AG gives no guarantee with regard to the timeliness, accuracy, completeness or quality of the information provided in this brochure.

Solarpraxis AG accepts no liability for damages, material or non-material, which are incurred through the use or non-use of the information provided or which are caused directly or indirectly by the use of erroneous and incomplete information, except where deliberate or grossly negligent culpability may be proven. Company entries are the sole responsibility of the respective company.

Picture credits

Solarpraxis AG/Dr Roland Ernst

To learn more:

www.isuppli.com/pv

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info@isuppli.com

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+49 89 2070260-61

Assistance to editorial department

Ute Bartels along with Jessyca Groß, Lena Kuhn, Sandra Steinmetz “The Industry” authors

Dr Detlef Koenemann, except

p. 31/32 (“A view on the United States”):

Ucilia Wang Ch. 2: Dr Henning Wicht/iSuppli “The Industry” technical proofreading

Christian Dürschner

“The Industry” translation

Übersetzungsbüro Peschel Layout & composition

Sunbeam GmbH/derMarkstein.de Photo editor & image processing

Tom Baerwald Infographics

Kay Neubert Website design by

Sunbeam GmbH Printed by

Druckhaus Berlin-Mitte GmbH Booklet website

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Solarpraxis Engineering Photovoltaics and Solar Thermal Services to give you a head start

Technical Due Diligences Acceptance Tests Quality Assurance Seminars / Seminar material

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Please contact Christian Steinberg, +49 (0)30 726 296-342, christian.steinberg@solarpraxis.de

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Companies: xxx

Companies: xxx

www.solarpraxis.com

PV Conferences 2012 Top marketing for your brand to the sector PV Project India 2012 September 2012, India PV Technology Conference – Maghreb 2012 September 2012, Casablanca, Morocco Quality for Photovoltaics 2012 6 September 2012, Berlin, Germany

June 13–15, 2012

Solar meets Glass – 3rd Industry Summit for Production, Logistics and Technology October 2012, Düsseldorf, Germany

The World’s Largest

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Messe München, Germany

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Solar Industry Summit – Middle East 2012 13 – 14 November 2012, Dubai, United Arab Emirates 13th Forum Solarpraxis 22 – 23 November 2012, Berlin, Germany PV Power Plants – USA 2012 28 – 29 November 2012, Phoenix, USA

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