Page 1

THE PROBLEM

With the increased awareness of global warming, and the ever-rising price of electricity, the University of Washington faces a daunting challenge to meet an increasing power demand on campus while cutting down on emissions of greenhouse gases. The natural gas burning plant that currently serves the school is part of this problem, as natural gas combustion is the second largest source of CO2 emissions worldwide. The figure below shows how while producing less than 10% of the UW’s power, this gas plant accounts for more than 40% of the school’s total carbon emissions.

COST ESTIMATE

Thin film roll with substrate callout [4]

HOW TFP WORKS

The figure above shows an expanded view of a thin film solar cell. The stacked layers are less than 500 microns thick, and form a semiconductor p-n junction between the two electrodes. Unlike traditional paneled solar cells, a non-silicon material such as cadmium telluride is used as the main semiconductor. The low production cost of these materials allows for several configurations, such as the solar shingles shown in the figure below.

UW’s sources of energy (left) and CO2 emissions (right) [1], [2]

THE SOLUTION

Widespread installation of a specific type of solar panel called Thin Film Photovoltaic (TFP) cells will help meet the UW’s energy demands while lowering its carbon emissions. TFP’s allow a cheap way to utilize solar power that can be applied to many different surfaces in order to increase power generation. Specific installation areas include the rooftops and even windows of university buildings.

The total estimated capital cost for the system is $1.5 million. These costs include installation, materials, and support equipment (such as DC to AC converters) necessary for this project. The payback period for the system is about 5 years. Additionally, there are other incentives, such as tax benefits, net energy billing, and renewable energy credits that will add to the savings provided by this system, and thus the system will pay for itself even sooner than 5 years. Once funds are released, the complete installation on the Seattle campus will take only three months. The table below shows conservative estimates based on covering 5% of the total campus area. Area of UW 

5%

Annual Output (kWh/6^2) 

5

% of UW Demand 

2.37%

Savings

$355,000  

CO2 offset (metric tons/yr) 

210

CONCLUSION

Organic thin film solar shingles [5]

INSTALLATION Two possible places for thin-film solar panel installation on the UW campus are rooftops and windows. Installation on both rooftops and windows can be as simple as a peel-and-stick process. The size of panels are customized for several types of rooftops: metal, flat, and shingled roofs. Meanwhile, research is being conducted to explore more thin-film solar panel alternatives such as spray-on panels and pre-fabricated solar windows for window installation.

The UW has been a leader in sustainability because of its sense of env ironmental responsibility. Incorporating solar into the schools energy portfolio will continue this trend. The main benefits of this project are: o  210 metric tons/year reduction in CO2 o  System pays for itself within 5 years o  Continued electricity savings of $355k/year over the lifetime of the system o  Sets the example for other schools to follow o  Uses environmentally friendly materials Should you have any questions concerning this project, feel free to email us at jgward@uw.edu REFERENCES

[1] The Source of Our Power – University of Washington, available at: http:// f2.washington.edu/cpo/sites/default/.../uw-energy-power-sources.pdf [2] 2005 Inventory of Greenhouse Gas Emissions Ascribably to the University of Washington, available at: http://www.washington.edu/facilities/files/documents/ UW_GHG_Inventory_2005_Final_PDF.pdf [3] Tesco Plan Worlds Largest Solar Roof, available at: http://www.reuk.co.uk/ Tesco-Plan-Worlds-Largest-Solar-Roof.htm [4] Seafarers: Charge Your Cell Phone with Solar Necktie, available at: http:// www.marinebuzz.com/2008/10/05/seafarers-charge-your-cell-phones-with-solarnecktie/ [5] My Solar Roof, available at: http://www.geology.wisc.edu/~jmbahr/roof.html [6] Seethrough Solar at MIT, available at: http://natureofbusiness.fm/news

Technicians installing thin film solar on a skyscraper [3]

Tinted thin film solar window coverings [6]

Solar Caps Proposal Poster  

A poster describing a proposal to cover rooftops and windows on the University of Washington's Seattle campus with a thin film solar

Read more
Read more
Similar to
Popular now
Just for you