Olympia’s Potential for Roof-Mounted Photovoltaics

by Nicholas Acorn and Spencer McLane-Higginson

Our Question:

• How much of Olympia’s electric demand can be met by rooftop-mounted solar photovoltaics (P.V.)?

….And could the implementation of P.V. be cost-effective when compared to the true cost of fossil fuels?

Motivation:

• Inspired by the Department of Energy’s Solar Cities program, which estimated the potential of solar P.V. for NYC.

• To test assumptions about P.V. in the Northwest.

• It is important to review the potential for renewable energy technologies like P.V. if we want to transition from using fossil fuels.

Do photovoltaics have potential in Olympia?

…It’s already here!

What factors decide the suitability of P.V. for a given area?

• Efficiency• Solar resource• Economics

http://inhabitat.com/solar-panel-roof-tiles/

www.NREL.gov

Economics• Astronomically high prices in the space race• In 1956 a one-watt cell costed $286

www.army.mil/article/37602/Early_Signal_Corps_satellite_programs_remembered

Hypotheses: Primary: Olympia has a potential roof-mounted P.V. resource that can

make a significant contribution to the city’s energy needs.

Alternative: Only parts of Olympia, like downtown, have enough potential to generate a significant amount of energy from roof-mounted P.V.

Another alternative: P.V. can generate a significant amount of energy but is more expensive than an alternative renewable energy resource.

Null: Olympia has a poor P.V. resource that cannot generate a significant amount of energy.

How do you estimate the power that could be produced if all of the rooftops in Olympia were

covered in solar modules?

-IMBY software developed by the National Renewable Energy Laboratory

Different areas call for different uses of IMBY

Compare to the true cost of fossil fuels• Each kWh from coal releases

about 2.3 lbs of CO2 (cdiac.ornl.gov/pns/faq.html).

• The IPCC found the mean social cost of carbon to be $40/tonne. That’s a little more than a penny/kWh of coal power.

• Transalta’s Centralia plant has a social cost of $450 million per year.

Contribution• Will have a better sense of the contribution

P.V. technology could make in the future• Will see how people’s assumptions hold up in

the face of in-depth analysis, and help to change those assumptions appropriately

Expected Outcomes

• Sunny areas with south-facing roofs will be the most economic.

• Wooded areas and roofs facing east, west or south will be less economically feasible.

• A significant fraction (~10%) of Olympia's power could be met by P.V. power.

Thank You!

• http://media.treehugger.com/assets/images/2011/10/solar-panel-sunset.jpg