By Dan Shapley
If you thought geothermal heating is something for Icelandic progressives sitting atop unique geologic features, think again. Geothermal is the misleading shorthand for a ground-source heat pump, which is available for both heating and cooling virtually anywhere in the United States. The systems harness the stable subsurface temperature of the earth by channeling water between interior pipes and deep wells. The deep temperature is cooler than summer air and warmer than winter air, so it helps moderate the temperature of any structure. Homeowners then pay less, and use less energy, to heat or cool interiors. As homeowners and communities search for energy-saving measures, the use of geothermal power is becoming more widespread. Many states offer subsidies for those who want to invest in the technology. That helps, since like many energy-efficiency improvements, short-term investments pay off only over time.