Copper Mountain Solar 1 Facility  |  Case Study

Flat Panel CdTe Thin Film Photovoltaic Solar Power Plant:  58 MW

  1. Built with First Solar CdTe thin film photovoltaic solar power technology and commissioned in 2010, the 58 MW Copper Mountain Solar 1 Facility was the largest operating solar PV power plant in the United States until the 2012 commissioning of the 100 MW Phase 1 of the Agua Caliente Solar Project.

  1. Located near the existing Sempra Energy El Dorado natural gas-fired power plant and transmission infrastructure, the 58 MW Copper Mountain Solar 1 Facility is efficiently integrated into the larger transmission grid, providing emission-free electricity to serve the needs of 20,000 California homes.  Unlike most power generation technologies, the Solar 1 photovoltaic solar power plant requires no water for operation or cooling.  Construction on the 468 acre site took place in slightly less than 12 months.  As of April 2012 the facility was the largest solar PV plant in the United States. 

  2. Following the successful completion of Solar 1, construction has begun on the Copper Mountain Solar 2 Facility 150 MW expansion.  92 MW is expected to be completed and online in January 2013.  The remaining 58 MW has a projected completion date of 2015. 

  3. The project was named “Solar Project of the Year” by Renewable Energy World as part of the 2011 Excellence in Renewable Energy Awards. 

  4. Technology

  5. The CdTe (cadmium telluride) thin film photovoltaic cell that is at the heart of the First Solar process is the most widely used thin film solar panel technology.  Other photovoltaic materials commonly used in thin film solar cells include amorphous silicon (a-Si) and copper indium gallium selenide (CIS or CIGS).  Although not as efficient as crystalline silicon photovoltaic panels, thin film technology continues to be less costly (although dropping silicon costs have changed this dynamic dramatically in the past year) and more adaptable to building integrated photovoltaic (BIPV) installations.

  6. As of mid-2012, the ten most efficient monocrystalline silicon solar cells range from 19.1% to 22.5%. The top ten polycrystalline cell efficiencies range from 15.24% to 16.0%.  By way of comparison, in early 2012, commercial panel conversion rate efficiencies for thin film industry leader First Solar had reached 12.4%

  7. Project Development

  8. Project developer First Solar is one of the largest solar panel manufacturers and solar project developers in the world.  The company was formed in 1999.  Among First Solar’s achievements:  

  9. In the current extraordinarily competitive market they are still the cost leader at less than $0.75 per watt.

  10. The were the first solar PV company to produce 1 GW in a single year and have over 5 GW installed to date.

  11. Set world records for CdTe PV cell (17.3%) and PV module (14.4%) efficiency certified by NREL.

  12. Developed the first comprehensive, pre-funded module collection and recycling program in the PV industry.

  13. Attained the smallest carbon footprint and fastest energy payback time of any PV technology.

  14. First Solar projects include over 5 GW installed and another 2.7 GW under construction or in development.  Among the noteworthy completed projects are the 80 MW Sarnia Solar Project, the 58 MW Copper Mountain Solar 1 facility, the 53 MW Lieberose Solar Park, and the 30 MW Cimarron Solar Facility.  Projects in development include the 550 MW Desert Sunlight Solar Farm. the 550 MW Topaz Solar Farm, the 290 MW Agua Caliente Solar Project, the 230 MW AV Solar Ranch One, and the 300 MW Stateline Solar Farm.

  15. The Copper Mountain facility was built by Sempra Generation, a subisidiary of Sempra Energy.  Sempra Energy operates and maintains a fleet of natural gas-fueled power plants, and develops solar and wind facilities that serve U.S. markets.  Sempra Energy, based in San Diego, is a Fortune 500 energy services holding company with 2009 revenues of more than $8 billion.  The companies’ 13,600 employees serve about 25 million consumers worldwide. 

  16. Sempra Energy is expanding its renewable energy portfolio throughout the Western U.S. The company expects to begin construction on the first phase of a 600 MW solar project in Arizona next year, and recently received approval to build a 200 MW solar farm in Kern County, Calif. The company also recently announced that it has become an equal partner with BP Wind Energy in the development of a 250 MW wind project in Colorado that is currently under construction.

  17. Levelized Cost of Energy

  18. In 2012, the U.S. Energy Information Administration’s Annual Energy Outlook (AEO2012) estimated that the best case scenario levelized cost of energy (LCOE) for a generic new commercial-scale photovoltaic solar power plant would be $0.1222/kWh.  This best case estimate would be for an installation in a solar resource-rich location (southwest U.S.) and does not differentiate between silicon and thin film technologies.  This figure is inclusive of all direct costs and does not include any incentives or subsidies.  The AEO2012 LCOE figure represents a rather remarkable one year 23% ($0.0365/kWh) drop from the AEO2011 projections.

  19. For more information on LCOE and how photovoltaic solar power generation costs match up, see:  Levelized Cost of Energy:  Renewable energy has achieved parity.

  20. Financing

  21. Financing for the project benefited from federal tax credits equal to 30% of the project cost ($42 million) and state tax abatements and reductions valued at $12 million.  The project did not receive any federal loan guarantees.

  22. References

  23. Renewable Energy World:  America’s Largest PV Power Plant is Now Live


  25. First Solar:  El Dorado and Copper Mountain Solar Projects


  27. Sempra Generation Press Release:  Sempra Generation completes largest U.S. photovoltaic solar power plant


  29. Wikipedia:  Copper Mountain Solar Facility


  31. Wikipedia:  List of Photovoltaic Power Stations


  33. SEIA (Solar Energy Industries Association):  Major Solar Projects Llst



  1. Boulder City, Nevada, United States

Project Status:

  1. Solar 1 (58 MW) commissioned:  December 2010

  2. Solar 2 (150 MW) completion:  2015 (projected) 

Rated Capacity:

  1. 58 MW

Annual Production:

  1. 124.0 GWh per year

Capacity Factor:

  1. 24.0% (solar resource:  2,303 kWh/m2/yr)

Carbon Offset:

  1. 35,000 metric tons per year


  1. Sempra Energy, Inc.


  1. First Solar, Inc.


  1. First Solar, Inc.

Generation Offtaker:

  1. Pacific Gas and Electric (PG&E).  20-year PPA

Generation Technology:

  1. 1,000,000  fixed-tilt (25 and 30 degree), ground-mount First Solar FS-272/275/277 CdTe thin film photovoltaic panels

Thermal Storage:

  1. N/A


  1. $141.0 million