CWE Price Zone Study TF – Study of existing cases and preparation of the qualitative analysis
3.1.10 Discussion points on loop flows Congestion analysis has a predominant inner German focus in the Frontier Economics/Consentec report.
Figure 7 Examples of loop flows due to power transfers within and between bidding areas (Figure 5 from the Frontier Economics/Consentec report) With regard to loop flows the following statements are made in the Frontier Economics/Consentec report: • The fact that power transfers inside a bidding area lead to loop flows is sometimes used as an argument for splitting up that area. However, the examples above (Figure 7) show that loop flows are created by internal as well as cross-border power transfers. • Hence, the magnitude of the loop flows due to internal transfer in Germany is independent of the question whether the direct flow through Germany leads to overloading of a line. Rather, internal congestion management measures such as redispatch and countertrading help limiting the loop flows because they induce counter flows in foreign networks (i.e. loop flows in opposite direction) as well. • To summarise, loop flows are technically inevitable, they occur irrespectively of the existence of congestion, and they need to be accepted according to EU law. Consequently, the occurrence of loop flows does not constitute a reason for altering the size of bidding areas. In the Frontier Economics/Consentec report loop flows and transit flows are compared as if they are actually ‘comparable’, which is not the case. In section 5.3.1, loop flows and transit flows will be touched upon more in depth, and it will be demonstrated that by splitting up a bidding area, loop flows can be altered into transit flows. Vice versa, by merging bidding areas, transit flows can be altered into loop flows.
3.2 APG case (Germany/Austria) 3.2.1 Reference to the report, to whom issued the case study, and to whom performed the case study The APG case (Germany/Austria) Case owner: APG Study report • Auswirkungen von Marktgebietszuschnitten auf das Höchstspannungsnetz der Austrian Power Grid AG und auf kritische Leitungen in Deutschland, Tschechien und Polen, 7 December 2011, RWTH Aachen University, IAEW (Institut für Elektrische Anlagen und Energiewirtschaft) (Report in German) • Impact of a German/Austrian market splitting on the transmission grid of Austrian Power Grid (APG) and critical lines in Germany, Poland and Czech Republic, 20 September 2011, RWTH Aachen University, IAEW
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