Geothermal Heating

There are two basic kinds of geothermal energy available that determine where you'll be able to use it. Therefore, you must ask yourself, "Where is geothermal energy available?" before you can decide how you'll utilize geothermal benefits. Because there are far greater energy input considerations when actually generating electrical power from geothermal energy and it is less available, passive geothermal finds a much more widespread use in North America and elsewhere.

The first and somewhat less common type of energy is that used to actually spin turbines and create electrical power. This requires you to be on a geothermically active site. Passive geothermal is a means of heating and cooling using the steady 45-50F (8-10C) of the Earth to moderate the temperature of an aboveground home, as most are. If you live in a seismically stable region such as the vast middle and eastern sections of North America, passive geothermal is your only, though lucrative, option.

Sites of active geothermal energy production tend to be dramatic landscapes, near mountains that are being pushed up where continental plates meet. This means that geothermal power generation is often found near coastal areas, but rarely on them. Places that have geysers and lots of bare rock around are more likely candidates. Areas with mineral springs are also very likely to have a heated spring nearby. Most people have no idea when you ask them, "Where is geothermal available nearby?" even if they know where the signs of geothermal activity are found.

For use with industrial power generation, however, the water coming out has to be superheated. Because they're under intense pressure, water boils at a much higher temperature. Some springs have steam escaping at over 700F (370C) at the fantastic velocities that are required to spin industrial turbines. Such vents often run out much quicker than those that are allowed to come out of naturally occurring vents, such as the geysers one finds in Yellowstone Park that have been spewing hot water for thousands of years.

Passive geothermal can be used anywhere you have the ability to bury a pipe in either the ground below or a nearby pond or lake. In one system, a given quantity of water of glycol is circulated in a closed run of several hundred feet of pipe. In a pond or lake system, the water (often under many inches of ice) is pumped in and circulated into the house, then back out to the pond again.

The best use of geothermal energy depends on the type of energy the earth around you is producing. It may simply be the heat of mass (the whole planet being a mostly contiguous, very heavy thing) that you have to take advantage of, but even though it doesn't gush or steam, this can prove to be a very powerful part of a non-polluting, "renewable" system.

Geothermal Heating |