WASHINGTON - Mike Tidwell's electric meter was spinning in reverse.
He was standing outside his Takoma Park, Md., house watching the metal disk count down. "I'm selling it to Pepco right now," he said one day recently.
Tidwell, an environmental activist concerned with climate change, has outfitted his home with energy-efficient appliances, a corn-burning stove and solar panels. Now, the two-story house sometimes produces more electricity than it needs and sends the surplus to Pepco's distribution system.
Homeowners alarmed about utility rates and greenhouse gases are seeking to slash their power use or produce their own energy from renewable sources. Among them, Tidwell and a handful of others have succeeded in creating homes that require only minimal energy from power plants and fossil fuels.
What they are doing - not going off the grid, but often going without its power - is not cheap or easy. But they want to prove it is not impossible.
"I'm not living in a cave and freezing to death," Tidwell said. "The point is, this is do-able."
Interest in such projects seems to be growing, albeit from very low levels. At Chesapeake Wind & Solar, a Jessup company that installs solar panels, business has doubled every year for the past three years. The company installed more than 100 sets last year in the mid-Atlantic region.
Some homeowners are making changes to avoid higher utility costs.
But often, the goal is to combat climate change. The average American house contributes more than twice as much greenhouse gas - pollutants that trap heat in the Earth's atmosphere - as the average car, according to the Environmental Protection Agency.
Tidwell said he started changing his house in 2001 after he had a "personal, spiritual, professional, emotional transformation" about global warming. Tidwell, who had been a freelance writer for publications, including The Washington Post, became an activist. His house, once an ordinary 1915 bungalow, has become perhaps the closest thing to a "zero-carbon" home in the area.
Tidwell and his then-wife started with a $7,500 home-equity loan. They replaced incandescent light bulbs with more costly compact fluorescent bulbs, which work in the same fixtures and provide the same light but use a third as much energy. They bought an EPA-designated "Energy Star" refrigerator, which cost $150 more but used less than a third as much power.
For heat, they replaced a natural-gas furnace with a $2,400 stove that burns corn kernels. Because corn consumes carbon dioxide as it grows, burning it doesn't release new greenhouse gases, he said. The corn, of a type used for animal feed, is grown in Mount Airy, Md., and brought to Takoma Park in a truck that burns soy-based biodiesel fuel. In town, the corn is stored in a 25-foot-tall silo owned by a community cooperative. In especially cold months, Tidwell has to get a load once a week.
One recent chilly day, there were flames eight inches high in the stove as kernels tumbled slowly down a tube and into the fire. A thermostat in the next room read 70 degrees.
"That is 100 percent corn," Tidwell said.
On his roof, Tidwell put an array of photovoltaic solar panels to produce electricity. He received grants to help pay for the panels and installed them himself, holding the cost to about $3,400. He also got a deal on panels that heat water: $1,000, or about half current prices, for a set pried off the roof of a departing Clinton administration official.
Even with those changes, Tidwell's house doesn't supply all its power. He still gets about half of his electricity from the grid and about 40 percent of his hot water from a backup natural-gas system. He pays about $200 extra a year to buy power generated by windmills - enough "clean energy," he said, to offset the fossil-fuel energy he uses for his house and car. The money goes to a kind of brokerage, which passes it on to the wind-power producer.
The lights in Tidwell's house, which he shares with his school-age son and a housemate, are kept off in daytime to save energy. All the heat comes from the stove, on the first floor. When the corn runs out, so does the heat. If he doesn't plan ahead, that can mean a late-night run to the silo. But Tidwell said he is proud that the place is so close to normal.
"There are people who say it cannot be done," said Tidwell, who holds open houses every two months to show other people what he is doing. "I've done it, and I've done it on a budget, and I have a great life."