What is Geothermal?
Geothermal energy refers to the potential of using the Earth’s near constant temperature (45—58 degrees F) a few feet below the surface for heating and cooling applications. Animals and people have always known to burrow under ground or seek respite in caves to avoid uncomfortable weather. Vermonters commonly use root cellars for food storage- and go on vacation somewhere with hot springs during winter. Geothermal heat pumps (or ground source heat pumps) use this principle to transfer heat through water or other liquids from one space to another.
Geothermal electric plants, commonly located near hot spots and the edges of tectonic plates, that use steam to turn turbines are not included in the Atlas. There are two types of potential geothermal systems currently featured in the Atlas: open loop systems and closed loop systems. A potential open loop system is indicated by the location of an existing water well. With open loop systems, water is pumped or flows from a well and passes through a ground source heat pump (GSHP) system or heat exchanger. The water is then either returned to the well for reheating (Standing Column Well) or is disposed of (permits may be required if the water is primarily disposed of). With closed loop systems, a series of looped pipes are placed in the ground (horizontally or vertically) or even in a pond or water body. Water or other liquids in the looped pipes then pass through a ground source heat pump.