FAQs
Below are frequently asked questions regarding the Solar Rooftop Program. If you have any additional questions that were not answered below, please contact Lorena Muñoz at solar.rooftop@sce.com.
- Describe SCE's new Photovoltaic installation plan.
- Why has the utility undertaken such a large Photovoltaic program?
- You mentioned the state's Million Solar Roofs program. Will SCE's new Photovoltaic project receive funding from that state program?
- Does SCE help administer the Million Solar Roofs program?
- Why is SCE installing most of its new Photovoltaic modules on commercial rooftops?
- I've seen a picture of your chairman announcing the new solar program on a warehouse roof in Fontana, CA. Is that where SCE plans to install its first panels?
- How much power would that one Fontana rooftop produce?
- Is this SCE's first foray into solar generation?
- How do photovoltaic panels produce electricity?
- What are the components of a photovoltaic generating system?
- What's the difference between Photovoltaic and other solar energy technologies?
- How long do Photovoltaic systems last?
- Describe SCE's new Photovoltaic installation plan.
On March 27, 2008 SCE launched a plan for the nation's largest installation of photovoltaic power generation modules. The utility plans to cover 65 million square feet of unused Southern California commercial rooftops with 250 megawatts of the latest photovoltaic (PV) technology — enough generating capacity to meet the needs of approximately 162,000 homes. This program is a revolutionary approach to solar in that SCE pays for the installation, maintenance and removal costs of the Photovoltaic power generation modules while leasing the rooftop space from the building owner. This model frees the building owner from the initial investment burden of solar power generation, provides an additional revenue stream for commercial property owners and improves SCE's power generation capabilities.
- Why has the utility undertaken such a large Photovoltaic program?
SCE believes this is the time for a major commitment to photovoltaic power generation, that the new program would produce significant benefits for its customers and California.
- New PV technologies have lowered the cost of installed PV generation, making investment more cost-effective at this time.
- SCE's goal is to reduce the installed cost of solar PV power from about $7.00 to $3.50 per kilowatt through economies of scale in purchasing and through innovations in technology.
- Lower costs will provide a boost to California's Million Solar Roofs initiative. SCE hopes its commitment to PV generation will help draw attention and added participation in the state program administered by utilities that provides financial incentives to home and small business owners who install the units (for details see www.sce.com/csi).
- The project increases SCE's renewable energy portfolio, already the largest in the nation.
- And the new PV program provides California with yet another tool to implement its ambitious climate change legislation — Assembly Bill 32.
- You mentioned the state's Million Solar Roofs program. Will SCE's new PV project receive funding from that state program?
The Million Solar Roofs program is also known as the California Solar Initiative (CSI). At this time, only customer-owned PV installations qualify for the state incentive. SCE's project would be owned by utility shareholders. More information on CSI can be found at www.sce.com/csi.
- Does SCE help administer the Million Solar Roofs program?
Yes. SCE is offering customers $996 million in incentives with the goal of helping them install 805 megawatts of new solar generation. Since the program's inception in January 2007, SCE has processed 2,200 applications from its customers that will lead to the installation of 105 megawatts of new solar generation within SCE's service territory.
- Why is SCE installing most of its new PV modules on commercial rooftops?
The unique approach developed by SCE — placing photovoltaic modules across millions of square feet of unused industrial building roofs in the Los Angeles basin addresses two problems common to major solar projects. Utility-scale solar plants require large parcels of land making it too costly to locate them close to population centers. However, placing solar facilities in remote areas requires the construction of new transmission lines to deliver their power to areas where it is needed, raising costs and delaying deployment of renewable technologies.
The SCE plan calls for placing solar modules on unused commercial rooftops in areas where power demand is growing. The panels would be connected directly to neighborhood power delivery circuits, eliminating the need for new, costly long-distance transmission lines.
- I've seen a picture of your chairman announcing the new solar program on a warehouse roof in Fontana, Calif. Is that where SCE plans to install its first panels?
Yes. The Inland Empire — San Bernardino and Riverside counties — was selected due to its increasing demand for electricity and its abundant sunshine. Locating some of SCE's new solar generating facilities here will help increase grid reliability for Inland Empire customers. This area's high solar index rating provides greater efficiency in producing solar power.
- How much power would that one Fontana rooftop produce?
We have installed 33,700 PV panels at that first location, using about 500,000 of that 600,000 square feet of roof space. That first site is capable of producing about 2 megawatts of power, or enough power to serve approximately 1,300 homes.
- Is this SCE's first foray into solar generation?
No. From the 1990s to the present, SCE has been involved in developing and bringing online innovative PV and concentrated solar projects that demonstrate the viability of solar power. The following are examples of the utility's involvement in advancing solar energy.
Solar Neighborhood Program — During the 1990s, SCE installed PV systems at schools and universities, such as the University of California, Irvine, and Cal Poly Pomona; civic centers; amusement parks, such as Pacific Park, Santa Monica Pier (see below), and Knott's Berry Farm.
Solar-Powered Ferris Wheel — The PV system designed, manufactured and installed by SCE at the Santa Monica Pier is the world's first solar-powered entertainment ride. An educational kiosk, located at the base of the Ferris wheel, informs the public about PV energy.
Glenmeade and Monterey Hills schools — Installation of PV systems in elementary schools provided possibilities for multiple uses. Solar technology was introduced to students while also generating electricity for the schools, in one instance, sheltering the outdoor lunch area.
Discovery Science Center — Working with the Department of Energy and the California Energy Commission, SCE installed more than 460 PV panels at the center dubbed the "amusement park of the mind." The panels converted sunlight into about 20 kilowatts of energy, saving the center approximately $8,000 annually on its electricity bill.
Solar Two — Starting in 1992, SCE led a consortium of U.S. utilities and high-tech industries with the Department of Energy, the California Public Utilities Commission and the California Energy Commission to construct, operate and maintain Solar Two, a $53-million, 10-MW concentrated solar tower collaborative research project in Daggett, CA.
Solar Two demonstrated the technical feasibility of using a molten salt receiver and a thermal storage system to store and deliver large-scale solar energy into the grid. The project served as the prototype for further U.S. and international development and commercialization efforts of power tower systems. The project supplied 10 megawatts of renewable power to SCE customers from 1996 to 1999.
- How do PV panels produce electricity?
Solar cells are made of materials that convert sunlight directly into electricity through a chemical reaction.
- A thin semiconductor wafer is treated to form an electric field – positive on one side and negative on the other side.
- When light strikes the cell, electrons are knocked loose from the atoms of the material creating the current.
- Wires are attached to the positive and negative sides to carry the electricity from the cell to the device to be powered.
- What are the components of a PV generating system?
A photovoltaic system consists of groups of PV panels, racks, inverters, combining boxes, wiring, and switch gear and transformer for a utility-grid-connected system.
- What's the difference between PV and other solar energy technologies?
There are four main types of solar energy technologies:
- PV systems, which convert sunlight directly to electricity by means of cells made of semiconductor materials.
- Concentrating solar power systems, which concentrate the sun's energy using reflective devices such as troughs or mirror panels to produce heat that is then used to generate electricity.
- Solar water heating systems, which contain a solar collector that faces the sun and either heats water directly or heats a "working fluid" that, in turn, is used to heat water.
- Transpired solar collectors, or "solar walls," which use solar energy to preheat ventilation air for a building.
- How long do PV systems last?
A PV system that is designed, installed, and maintained well will operate for more than 20 years. The most common problems with PV units occur because of poor or sloppy system installation, including failed connections, insufficient wire size, and components not rated for direct-current application.
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