By Jonathan Marshall
Alcatraz, the gloomy and infamous former prison known as “The Rock,” now has a new claim to fame as one of the National Park Service’s brightest showcases for clean energy.
The longtime home to Al Capone and “Machine Gun” Kelly in San Francisco Bay now houses 1,300 photovoltaic panels and a huge backup battery supply that have slashed the tourist site’s dependence on expensive and dirty diesel fuel. The solar installation is helping to clean the air, reduce corrosion, and save taxpayers money to boot.
Completed with $3.6 million in funding from the American Reinvestment and Recovery Act, and with design assistance from the Department of Energy’s National Renewable Energy Laboratory (NREL), the solar plant atop the main Cellhouse building generates 307 kilowatts of power at peak output.
When dense fog obscures the sun, a roomful of lead-acid batteries provides backup energy to power lights and appliances throughout the island. They are connected to inverters (which convert DC to AC power) and to diesel generators through a sophisticated micro-grid.
The island was once connected to PG&E’s power grid, but the cable was severed by a passing vessel’s anchor almost 50 years ago. The island was powered instead by a 210-kilowatt diesel generator, which required imports of 2,000 gallons of fuel each week. A 2008 study determined that attaching a new undersea cable would cost $2.5 million. It supported investment in solar panels, judging other renewable alternatives—wind and tidal power—to be far less cost-effective.
The unobtrusive solar installation now allows the landmark to slash its reliance on diesel generators by 60 percent. As a result, carbon dioxide emissions will be reduced by almost 750,000 pounds a year. And with less fuel to purchase and transport, the cost of electricity has dropped from 76 cents to 71 cents per kilowatt-hour.
The project dates back to the mid-1990s, but ran into critics’ complaints that designs were too visible and intruded too much on historic sites such as the New Industries Building, which employed hardened convicts in laundry and sewing services. Federal stimulus funding gave the project new life in 2009. Newer, high-efficiency solar cells permitted the entire plant to be placed out of sight over the Cellhouse building.
PG&E wasn’t involved in the Alcatraz installation, but it has long been a supporter of parks in Northern and Central California through donations and volunteer activity. On the solar front, PG&E has provided money-saving rebates to Pt. Reyes National Seashore, the Golden Gate National Parks Conservancy (Fort Mason), and Lassen Volcanic National Park, as well as several county and city parks from Mendocino to Kern Counties.
Email Jonathan Marshall at firstname.lastname@example.org.