San Francisco savors solar energy
Despite its reputation as a fog-shrouded city, San Francisco is acting to tap solar energy. It is the first U.S. city to approve issuance of bonds to finance renewable energy systems. Frustrated by a series of electrical brownouts and blackouts, San Francisco voters in November 2001 approved the issuance of $100 million of revenue bonds to finance renewable energy systems for municipal facilities, as well as to issue an unlimited amount of bonds for private residential and commercial facilities. Installation of solar panels on the roof of the Moscone Convention Center, now in progress, is the first tangible result of this initiative. Other targeted sites for the panels include administrative buildings, libraries, and fire stations.
Over the next five years, the city expects to add 10 megawattts of solar power to its electrical grid. Its long-term goal is to provide about 5% of peak electricity demand with solar-generated electricity.
Until the bond financing is in place, the projects will be funded by an allocation from the water and power department's $120 million of annual revenues, according to Fred Schwartz, manager of renewable and advanced generation with the San Francisco Public Utilities Commission.
A solar monitoring program has been established in 11 city districts, seven of which are showing "good solar irradiance," Schwartz reports. He expects to soon issue an RFP for the installation of solar panels on a city water pollution control plant and is eyeing the roof of a large water reservoir in the city's "best solar regime," where he envisions the future installation of as much as 800,000 sq. ft. of solar collectors.
The Moscone Center panels will be installed by PowerLite Corp., Berkeley, Calif., utilizing photovoltaic modules manufactured by Shell Solar and Sanyo Electric Co. The installation's peak output will be 675 kilowatts, and it is expected to generate about 825,000 kilowatt hours annually.
The integrated photovoltaic assembly is installed over an existing roof membrane. The photovoltaic modules use solar cells made of solid-state semiconductors to convert sunlight into direct current, which is then converted to alternating current.
Federal action may give further impetus to the financing of renewable energy systems. The U.S. House last month passed an energy bill that includes $30 million annually to help state and local governments incorporate renewable energy systems, including solar, into public buildings. It was unclear whether the Senate version of the bill will retain this provision.
San Francisco’s Moscone Convention Center will be the first beneficiary of the city’s program to incorporate renewable energy systems into its public buildings. This photo depicts the appearance of the center’s roof following the installation of 60,000 sq. ft. of solar panels.