PV in Your Home

If you are interested in incentives for PV systems for your home or business, please visit the: Go Solar California! Website.

Solar photovoltaic cells are small, square-shaped panel semiconductors manufactured in thin film layers from silicon and other conductive materials. When sunlight strikes the PV cell, chemical reactions release electrons, generating electric current. The small current from individual PV cells, which are installed in modules, power individual homes and businesses, or can be plugged into the bulk electricity grid.

Solar PV has come a long way since its early origins in the space program powering satellites and other extraterrestrial vehicles more than four decades ago. The technology has come down to earth and now is the first power supply choice for much of the developing world. They are also appearing on rooftops and years around our state to provide power during daylight hours.

There are two primary PV markets. Off-grid systems are used where the cost of a PV system is cheaper than stringing electrical power lines long distances from the local utility. Grid-connected PV systems usually cannot compete directly with the cost of utility-produced power. However, with the changing deregulated marketplace, many people are considering grid-connected PV systems. If the PV system provides more power than the home or business uses, additional electricity is fed back into the grid for other people to use. This effectively spins an electricity meter backward in what is known as "net metering."

Incentives are being offered to homeowners and small businesses by some states to help develop a more robust PV industry. For more about the current incentives and rebates, please visit the Go Solar California! website

From 1998 to 2006, solar/PV incentives for systems under 30 kilowatts were handled by the California Energy Commission's Emerging Renewables (Buy-down) Program. Larger systems were funded by the California Public Utilities Commission (CPUC) and the Self-Generation Program with the electric utilities.

From 1998 to October 31, 2006, nearly 175 megawatts of solar electric capacity was installed in California under the two programs.

Beginning January 1, 2007, all solar/PV rebates on existing homes and businesses will all be handled by the electric utilities under the California Solar Initiative at the direction of the CPUC. The Energy Commission will focus on solar on new home construction, along with rebates for small wind and fuel cell electricity systems.

Types of PV systems

Photovoltaics or solar cells can be purchased in two formats: as a stand-alone module that is attached to your roof or on a separate system, or using integrated roofing materials with dual functions -- that as a regular roofing shingle and as a solar cell making electricity.

Because they do not produce polluting air emissions or water effluents, solar PV systems are prime candidates for supplying electricity at locations where such environmental impacts are unacceptable; for example, in parks and places where preserving high levels of environmental quality is important.

Solar Products

There are many solar PV products on the market.

One of the more intriguing recent advances was just announced by Toshiba for the Graetzel cell, a new type of solar panel that consists primarily of titanium dioxide nanocrystals coated with a dye. The new cells could be manufactured by silk-screen printing technologies. At present, at least seven companies in Japan, Europe, and Australia are developing improved Graetzel cells that may end up gracing cell phones, laptops, and even windows in energy-efficient homes.

BP Solar panels quietly and beautifully transform atria, glass roofs, and roof lights into electricity generators. The most impressive products, nevertheless, are PowerWalls, which arrange solar cells in patterns framed by curtain walls erected with traditional glazing techniques.

Powerlight Corporation of Berkeley, California, has developed a unique mounting platform that integrates a variety of PV products into rooftops. A foam insulation reduces heating and air-conditioning costs. The light-weight solar PV modules also extend the life of the roof by protecting it from the damaging effects of weather.

The building-integrated products manufactured by Atlantis Energy of Grass Valley, California, offers custom glass PV laminates, which turn windows into micro-power plants.

How much does a PV system cost?

The cost of a PV system depends on the system's size, equipment options, and labor costs. Prices vary depending on other factors as well, such as the PV provider, whether or not your home is new, if the PV is integrated into the roofing materials or mounted on top of the existing roof, and the PV manufacturer. Small systems funded through California's Buy-Down Program have been averaging $7.00 / watt, after rebates.

Is the site a good place for a PV system?

The property should have clear, unobstructed access to the sun for most of the day and free from shade. The best orientation for a PV system is on a south-facing roof. If your location looks promising, a PV provider can trace the sun's path for you and determine whether your home or business would benefit from a PV system. Typically, composition shingle roofs are the easiest to work with.

Solar Access

State laws in California protect homeowner's access to the sun for solar systems. A portion of the Warren_Alquist Act -- Public Resources Code Section 25980-25986, the Solar Shade Control Act, states "...It is the policy of the state to promote all feasible means of energy conservation and all feasible uses of alternative energy supply sources. In particular, the state encourages the planting and maintenance of trees and shrubs to create shading, moderate outdoor temperatures, and provide various economic and aesthetic benefits. However, there are certain situations in which the need for widespread use of alternative energy devices, such as solar collectors, requires specific and limited controls on trees and shrubs."

If you have questions regarding this law, please check with your legal adviser, county building official, or your solar equipment installer.

More Information About PV Systems for Homes and Business

Download Buying a PV Solar Electric System - A CONSUMERS GUIDE. (29 pages, 388 kilobytes).

Download A Guide to Photovoltaic (PV) System Design and Installation. (40 pages, 365 kilobytes).