OLD LYME, Conn. -- Want to save money on heating your home? Try going geothermal.

An Old Lyme family has found a way to harness geothermal energy and save money on heating its home in the winter and cooling it in the summer, Hartford television news station WFSB reported.

Family Trades Oil Furnace For Energy From Earth

Jonathan and Linda Hamilton said their home is green. Last spring, they replaced their aging hot-air, oil-fired furnace and air-conditioner units with a geothermal heat-pump system, cutting their electric bill and helping the environment.

Geothermal technology takes advantage of the natural, constant 55-degree temperature of the Earth below the frost line.

At the Hamiltons' house, a heat pump transfers heat stored in the Earth or in groundwater into a building during the winter, they said. During the summer, they said, the pump transfers it out of the building and back into the ground.

A series of pipes, commonly called a "loop," is buried vertically or horizontally in the ground near the building to be conditioned. The loop circulates a mixture of water and antifreeze that absorbs heat from, or relinquishes heat to, the surrounding soil.

"The oil tank is gone. Gone!" Linda said. "Kind of hard to believe isn't it? It's fabulous."

"We used roughly 700 gallons last year, roughly $4 a gallon," she said. "That's $2,800 right there. Our electric bills have gone, usage has gone down 30 percent. We've seen a 20 percent decrease in our electric bill, and we have 80 gallons of hot water with our new system where we only had 40 gallons last year. So, do the math."

The Hamiltons said they're saving a lot of money now with their geothermal system. Without paying for oil, they said they’re saving about $300 per month.

They said they're also saving about $40 per month on electricity.

"I suppose the proof in the pudding will be this December and January," Jonathan said. "We're anticipating a very cozy winter in our house."

When asked about the drawbacks of the system, Linda said, "I haven't found one yet. Honestly, I have not found a drawback yet. Our electric bills have gone down."

The Hamiltons said the geothermal system was a little more expensive than replacing their furnace and air conditioner, but it came with utility company rebates per the size of the unit.

The cost to replace the furnace and air-conditioning unit would be $12,000 for a new furnace and $8,000 for a new air conditioner, totaling $20,000.

The cost of the geothermal system included $9,000 for drilling and $14,000 for the heat pump, totaling $23,000. However, the Hamiltons said the geothermal system came with $2,000 to $3,000 in rebates.

"So, comparing the price of the geothermal system to a new oil system, it was almost even," Linda said. "We paid $1,000 or $1,500 more for the geothermal system."