Current Use: PV in the Home

A: The availability of federal tax credits for PV systems, additional credits in more than half the states and growing use of net metering, renewable portfolio standards and other financial incentive programs have stimulated tremendous interest in using photovoltaics (PV) in homes in the U.S.

It's hard not to find a reference to zero-energy homes in newspapers and magazines, with PV forming the heart of any system that has truly near- or completely zero energy use. Costs for a 4-kilowatt (kW) or 5-kW system that could power your whole home are still high, but even at current residential PV costs of $7 to $10 per watt, you can cut PV energy costs with the incentives to very close to today's conventional utility rates for smaller systems (caps on the credits generally keep them from full use on the larger systems).

But don't be discouraged if you can't afford a whole-house system. A smaller system of 2-kW, for example, could provide enough power to run about half the electric-powered appliances and lights in the typical home, including the refrigerator. That sized system has the capability of producing 7 to 8 kWh a day, so if you're a typical electric user of around 1,000 kWh month, the system could produce about 25 percent of your electric needs.

Even if you're not looking for a rooftop system for your home, there are other PV products available today that'll help save energy. The technological advances in garden and walkway lights now give you the choice of products that will provide the light you need for several hours or even all-night long. PV-powered roof ventilators will help lower attic temperatures and keep your house more comfortable while you use less air conditioning.

And if you live in a remote location or have a cabin or farm far from the power grid, it's usually cheaper to install a PV system rather than pay fees ranging from $5,000 to $20,000 per mile to run the power lines to your location. Many rural homes and farms use PV systems for water pumping, electric fence charging, outdoor lighting and other needs.

Don't forget that the more efficient you make your home, the more impact the PV system will have -- since efficiency measures lower the overall energy load. So thanks to the incentives, PV for home use may not be totally cost-efficient, but it's getting closer all the time and bringing with it environmental benefits as well.

-- Ken Sheinkopf