Some homeowners chase down high-tech solar panels and efficient appliances to make their homes environmentally friendly. Others eschew the latest technology in favor of something far more basic: caves.
Geothermal heating and cooling systems work just as caves do: The temperature underground is more moderate than the air above. If it's 85 degrees outside, it's cool in the cave. If it's 25 degrees outside, the cave is still 50 to 60 degrees.
In a building heated and cooled by a geothermal system, a pump brings 55-degree ground water up into a heat pump. The heat pump extracts heat from the water and sends cooler water back down into the earth. In the summer, the process is reversed: The pump pulls hot air from the house and sends it down into the earth.
Because geothermal heat pumps are more efficient than air-to-air heat pumps, and because the ground water is closer to the desired indoor temperature than the air outside, geothermal heat pumps use less electricity and work better in cold climates than the original heat pumps did.
"The heat pump works in the same manner as a refrigerator does in a home. You're basically moving temperature from one place to another," said Anthony Ganio, president of Connecticut Wells in Bethlehem, Conn., a company that specializes in drilling wells for geothermal systems.
He said there has been increasing demand for geothermal systems in the last half-dozen years. About 60 percent of the jobs are residential.
But the generous tax credits that pay for 30 percent of a geothermal system's costs, funded by the stimulus bill, have not spurred a lot of work for his 16-person firm.
"I'd say we're doing about half the residential work we did last year. It's certainly slowed down," he said. "It's a direct result of the economy, especially the retrofit market. People have a hard time spending $40,000 to $60,000 on a complete upgrade of their heating system."
But once it's in the ground, there are substantial savings. Ganio said someone with a 6,000-square-foot home could expect to spend $280 for electricity year-round.
"You compare that to someone who's spending $350 to $500, even $700 a month to heat a building. It's two-thirds less energy costs," he said.
About 70 percent of the wells he drills are for new construction, and the rest are for retrofits. Most houses that convert already have ductwork; a geothermal system needs ductwork for air conditioning.
Marv Beloff, 81, chose geothermal for his new house on Beseck Lake in Middlefield, Conn., eight years ago, and he is pleased he did.
The 3,000-square-foot house uses a 1,350-foot closed-loop geothermal system. The system creates hot water that feeds pipes running under the floors, providing radiant heat.
"Essentially, our radiator is the floor," Beloff said. "We also have a blower, if the radiant heat is not enough."
Year-round, he and his wife keep the house around 70 to 72 degrees. "It costs us $5,000 a year to run everything," he said.
Installing geothermal costs an extra $20,000 because Connecticut Light & Power's clean energy fund covered the cost of drilling the wells.
"We are saving money," Beloff said. But that wasn't his primary reason for installing the system. It was his commitment to fighting global warming.
"I'm now on my third Prius," he said. "We should try not to pollute our atmosphere."
He likes that the furnace does not burn fossil fuels, though he knows the electricity that runs the pumps could contribute to global warming.
Builder Ron Gaudet is marketing a green community in Colchester, Conn., with 134 home sites on 425 acres. All the houses have geothermal heat and use solar panels to generate most of the electricity to operate the heat pumps. That combination -- and because the houses are built with extra insulation and high-quality windows -- means that a 2,400-square-foot house costs only $500 a year in utilities, he said.
The average price of a house sold at White Oak Farm was $475,000, he said, and homeowners get $20,000 to $30,000 in tax credits and payments from state and federal governments.
Gaudet said the 12 buyers so far -- 10 houses are complete -- definitely liked the alternative-energy aspect of the development.
"It's a big reason," he said. "It's not the main reason. They're looking at the long range. Nobody knows where the cost of home heating, oil and electricity is going over the next 10 to 15 years. Everybody agrees it's going to be higher than where it is now."
But for his first buyer, Mihir Patel, the alternative energy was the main reason. Patel, 36, and his wife, Kokila, moved to Colchester, even though it's farther from his work.
"We wanted to lower our carbon footprint and were also looking for ways to save on heating and cooling," Patel said. White Oak Farm was the only place in Connecticut that offered both solar panels and geothermal, Patel said.
For his nearly 2,300-square-foot house, Patel spends $30 to $60 a month for utilities in the summer and less than $200 in the winter, with just $70 of that on heating. It's higher in the winter because there's less solar energy to cover the electricity.
Patel said the federal incentives made the higher initial cost more palatable, and he said he's talking up the technology to his friends and acquaintances.
Bruce Robbin, president of the Eugene Steinberg Co. in Bloomfield, Conn., an HVAC specialist, said environmental, not financial, concerns motivate geothermal advocates. Robbin is installing a system at a West Hartford mansion right now, but other jobs his company has done have been for an office, school and church. There's only a 10 percent tax credit for commercial users.
"Really, all of the geothermal systems we've sold are for people who want the latest technology and want to be environmentally responsible," Robbin said. "The incentives do not really justify a payback that's short enough to want to do the job."
In the last year, geothermal accounted for 10 percent of his company's business. But now there are only two jobs for the company to bid on, and one is geothermal.
Business is down because of the recession, and his staff shrank from 35 to 30 people, he said.
Retrofits take only three weeks, including well-digging, and Ganio said the permits are not time-consuming to obtain.
Even though the systems are expensive, not all the homeowners have huge houses. "We've done homes that are 1,700-square-foot capes to 6,000-square-foot colonials," Ganio said. "I think it more has to do with the homeowner and how responsible they are with their carbon footprint."