You don't have to have a new home to consider going green. Even homes built in the 1800's can become more energy efficient.  Mike and Peggy Lewis know all about that. Their Mendon home was built in the 1800's and now with the help of new technology they are going "green".

"It's based on natural energy and it's coming from the earth and we won't be as dependent on oil, oil not being delivered. It's congruent with our lifestyle of being natural and organic," says Lewis.

Gleason geothermal is capturing the heat in the ground and using it to heat this home.

"We put lots and lots of pipe in the ground and extract heat from the ground because it's already there. We're just extracting it from the ground and moving it into the house," says Matt Gleason.

It's easiest to do this on a new build. But older homes can be retrofitted too. "Our house is drafty and they have to put more ducts in. And they have to go around the old beams and it's tricky," says Lewis.

In fact, homes like this tend to reap more of the benefits. "These house, because they're older and kind of cobbled together, tend to leak more energy. So an efficient source of heating and cooling you'll see a much better return on investment than a new home structure," says Gleason.

The Lewis's think this investment will pay for itself in five years. "This is like a no brainer. If you can figure out how to do this, it's unbelievably economically, smart," says Peggy Lewis.

And unlike solar and wind energy, geothermal can happen just about anywhere. "Sometimes there's no wind, no sun, but there's a lot of dirt," adds Mike Lewis.