Many want to reduce their electric bills. Some have environmental concerns; increasingly, consumers also are worried about the nation's reliance on foreign energy. Sensitivity has risen with the sharp upswing in oil prices, BP's Poulin says, though that affects gasoline prices more than electricity, which tends to be generated by coal or nuclear plants.
"People are starting to understand global energy issues - energy is going to be a commodity we will all have to pay more attention to," he says.
Still, Poulin acknowledges, the solar industry's growth so far is directly tied to government incentives. California is one of the nation's hottest markets: 4,500 homes put up solar panels last year because of its rebates. BP has teamed up with Home Depot there to sell solar systems directly in local stores.
More help could soon be on the way: Congress is considering an overhaul of the nation's energy policy that could result in the first federal tax credits for solar electricity in 23 years. The Senate approved sweeping incentives for renewable energy; the House chose more modest incentives. A conference committee has been chosen to work out the differences in the bills.
Costs falling sharply
Subsidies are critical, says Lowenthal, given the price tag. Solar systems have fallen sharply in cost; they're now half the price of a decade ago. The rooftop panels used to heat water, more commonplace than the electric ones, are even cheaper.
But equipping a home with solar electricity is still far from inexpensive. A 2.5-kilowatt system, the right size for an average home, costs about $20,000 - and rarely produces enough power to be independent.
"Most homeowners really can't afford to flip the cost on their own," Lowenthal says.
Few solar systems generate enough electricity to run an entire household. Most are tied into the local grid. Electric bills drop, sometimes steeply, but solar households usually have to continue to pay their local utility for power when their production is low.
Bill cut in half
The Yuhases put in a 3.2-kilowatt system. Two rows of shiny panels (manufactured by BP Solar) cover the southern part of their roof, facing the river. The system is neatly hidden from the road, attractive and working well, says Tom Yuhas. Still, it has cut their electric bill by only about 50 percent, and less on summer days when they run dehumidifiers and the pool.
Maryland has a "net metering" law that allows homeowners to effectively sell excess power generated by their solar panels back to their utilities. Usually, that occurs at midday, when demand at home is low but high at offices and stores.
However, the state does not allow a month-to-month carryover. That means the Yuhases can't conserve on sunny days in late fall to pay the bills during a winter snowstorm, when they will run an electric heat pump instead of their old oil furnace.
For Tom Yuhas, the best part has been his satisfaction at creating clean energy. He enjoys those sun-drenched days when he steps outside to check the electric meter. If the solar panels are generating enough energy, the dial will slowly spin backward.
"That's the neat part," he says.
It's one of the only signs his tranquil house on the water is now a power plant.