Southern California Edison is Leading California's Charge to meet the nation's most ambitious renewable portfolio standard (RPS) targets: 20% by 2010 and even higher in years ahead. To satisfy these aggressive targets, Southern California Edison (SCE; Rosemead, California, U.S.) has taken the initiative to add a planned 250 MW of new photovoltaic (PV) resources to its system.

While PV is a recognized and well-understood renewable resource, its development and deployment on a massive scale is an emerging and evolving practice. Another challenge is the cost of PV. Through SCE's PV program, costs could be driven down to reach US$3.50/W.

The first 2.44-MW installation of the initiative has been built and is currently providing virtually greenhouse-gas-free power to the grid. The experience and knowledge gained from this installation will help accelerate the commercial viability of PV, a critical component to the green goals of SCE, the state of California and the U.S.

FONTANA ROOFTOP PROJECT

SCE's completed 2.44-MW Fontana rooftop project is the first of many 1-MW to 2-MW systems that, in aggregate, will comprise SCE's proposed Solar Photovoltaic Program (SPVP). SCE is seeking approval from the California Public Utilities Commission (CPUC) to build and own 250 MW of PV, installed in the sunny eastern area of SCE's service territory, primarily in 1-MW to 2-MW systems, on top of huge warehouse rooftops. If the opportunity were to arise, SCE would consider constructing PV on rooftops that could accommodate systems larger than 2 MW, or even on a few ground-mounted systems.

The renewable-resource generating units in SCE's SPVP will be close to customer load centers and connected directly to the utility's distribution grid, thereby avoiding the extra cost (capital facilities and electrical losses) of delivering remote green power to load centers. The Fontana site is one of three pilot projects SCE is building in advance of the CPUC's final decision on the full program.

In selecting sites, SCE looks for roofs that are less than five years old and greater than 300,000 sq ft (27,871 sq m) on buildings that have little on-site load and are owned by a company or real estate trust, preferably with a portfolio of candidate buildings.

From a grid standpoint, the location must be served by a primary distribution circuit with the electrical characteristics to receive the PV-generated power.

The Fontana project site fit these criteria. The host building's rooftop is 600,000 sq ft (55,742 sq m), has little on-site load and is owned by ProLogis, one of the world's largest owners and developers of warehouse and industrial space. ProLogis served as general contractor during the construction of the Fontana PV unit on this building.

The PV array was designed and engineered by First Solar Inc. (Tempe, Arizona, U.S.). The array uses First Solar's FS 272 modules — cadmium telluride (cad-tel) thin-film products. The equipment used to convert the PV array's DC output to AC for delivery to the grid was designed and built by Satcon Technology Corp. (Boston, Massachusetts, U.S.). The project used four of Satcon's 500-kW Generation II inverters. The aggregate 2-MW (AC) output is stepped up to 12.4-kV primary distribution voltage through SCE's standard distribution switchgear and transformer.

ProLogis applied for construction permits with the local permitting authority. However, no permitting fees were required for the Fontana site, because the permitting authority had zoned this area to encourage construction of renewable green power. Approval by the local fire authorities was a bit more challenging, as PV is a relatively new technology to them, and PV safety coordination procedures with the utility and PV labeling standards had not been definitively specified. In the end, satisfactory solutions were negotiated with the permitting and fire authorities.

Gregg Electric Inc. (Ontario, California) performed the construction under a participating labor agreement with the International Brotherhood of Electrical Workers Local 47. Construction of the 2.44-MW unit took 60 days to complete.

The facility was commissioned on Dec. 1, 2008, by California Gov. Arnold Schwarzenegger and Ted Craver, chairman and CEO of SCE's parent company, Edison International.