On going geothermal

There's a new development near us called Stanton Lake Estates that's promising geothermal heating for every home. I was skeptical that geothermal would work here, but after reading Malcolm Gladwell's post The Case for Geothermal I've come around.

One problem is the amount of land required to do a shallow geothermal system. From Gladwell's post:

For our installation we had 3 trenches each 300ft long, 5ft wide and 5ft deep. Each trench had four 4inch pvc pipes in it; 3600 ft in all.

That's about a quarter acre of land just for the trenches.

The alternative is drilling deep, which is the only thing that would work for a small house like mine. As the Wikipedia entry on geothermal heating explains:

Pipes are... buried in deep, vertically-drilled holes, often 200 ft (60 m) or greater below ground level. Water and antifreeze (or other transfer fluid) are circulated through the heat exchanger (heat pump) and back out through the loops continuously. Some closed loop systems bypass a portion of their working fluid with a thermostat to keep the source temperature stable.

The other problem is the up-front investment required. Based on the numbers I've seen it would probably cost between $20,000 and $30,000 to convert my home to geothermal. Ouch.

But oil sands development is expected to triple its demand for gas over the next 10 years, so it seems like a good bet that gas prices will remain high. Which means geothermal heating could be a smart investment.

(NextEnergy is Canadian company offering geothermal heating and cooling systems.)