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Fossil Fuel Dependency Falls from 100% to 56% on Alcatraz Island



  • U.S. National Park Service
  • American Recovery and Reinvestment Act

Key Partners

  • National Park Service Golden Gate National Recreation Area
  • National Park Service Denver Services Center
  • Princeton Power Inc.
  • University of Washington
  • Lawrence Berkeley National Laboratory
  • U.S. DOE Federal Energy Management Program

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U.S. Virgin Islands


Andy Walker, 303-384-7531

An aerial photograph of solar panels on the Cellhouse building on Alcatraz Island

With the help of the National Renewable Energy Laboratory (NREL), U.S. Department of Energy (DOE), and National Park Service, solar photovoltaic panels are powering lights and appliances that have been powered by either coal or diesel fuel ferried across the San Francisco Bay. The island's solar panels produced over 325,000 kilowatt-hours of electricity in 2013, decreasing diesel generator use from 100% to 56%. And as an added benefit, the solar installation is reducing carbon dioxide emissions on the island by approximately 325 metric tons of CO2 per year.

NREL's involvement in the Alcatraz project began in 1995, when the DOE's Federal Energy Management Program enlisted NREL to monitor the strength of the sun at the island, conduct a feasibility study, and model what a solar installation would look like from up close and from across the bay.

Assistance by NREL and DOE's Federal Energy Management Program included measuring loads and the strength of the sun on the roof of the main cellhouse building for 14 months; conducting a feasibility study using the HOMER model; and rendering what a solar installation would look like from up close and across the bay. Later, when the project was funded by ARRA funds, engineers at NREL worked with the National Park Service to review the design and installation of the system, which included 305 kilowatt (kW) photovoltaic array atop the roof of the cellhouse. Surplus electricity generated by the solar panels at peak is sent to a 2-megawatt-hour valve-regulated lead-acid battery system, which was installed next to the island's new power plant.

Additional Information

Learn more about NREL's Federal Agency Technical Assistance, Technical Assistance for Islands and Solar Deployment and Market Transformation capabilities.