Geothermal energy is an up-and-coming energy source that is gaining some mainstream popularity.
Geothermal is about as green as energy sources can be, while taking up a very small amount of area on the surface. This, combined with the fact that geothermal energy plants can produce energy 24/7, immediately gives it a big advantage over solar and wind, which tend to take up large areas of land and are weather dependant. There is some confusion about geothermal though, since there are several kinds.
Among the types of energy falling under the umbrella of “geothermal” are geothermal energy plants and ground source heat pumps. Both of these technologies take advantage of energy stored in the ground, but they do it in quite different ways.
The most obvious difference between the two systems (at first glance) would be the depth of drilling required.
Geothermal energy plants require digging down a long way with drilling equipment into the ground, until the temperature is hot enough to boil water.
Ground source heat pumps (on the other hand) are mostly installed in the top few hundred meters of the ground. Some heat pumps do not even require drilling down. They rely instead on having a large coil buried in a trench or placed in a nearby body of water.
These differences exist primarily because of what each of these types of systems is trying to achieve.
A geothermal energy plant needs to produce electricity. One of the easiest ways to manage that is to use a turbine, which requires steam to run. As a result, high temperatures (hot enough to make water boil underground in order to create the pressure of steam) are needed.
Comparatively, ground source heat pumps work by using the ground as a way to store and draw energy out. This reduces the energy consumption that is otherwise used to hear a home or water. This works because the temperature a few feet below the surface of the ground remains fairly constant, regardless of the outside temperature and weather.
This means that in the summer when it’s hot, instead of transferring energy to the hot air outside to try and cool your house or office down, you can use the cooler soil, effectively using the energy by drawing it from the ground. In winter, you can draw heat out of the soil, still at a constant temperature just a few feet down, and use it to heat your home.
Geothermal options, especially ground source heat pumps, are generally more effective than standard heating. Using electricity to run a heater to warm your home; it is ~100% efficient; that is to say nearly all of the energy consumed is transferred into thermal energy. Using a heat pump however, you are using energy to move energy up from the soil, and as a general rule of thumb (not so true across large temperature differences), you can move more energy per unit of energy consumed.
Essentially, geothermal heat pumps can reach several hundred percent efficiency, which has been shown to reduce energy bills on heating in a large way.
Look into Geothermal if you are looking for a way to reduce your electricity bills, or if you are building your home new. The payoff periods can be shorter than you may think.
Geothermal is not only a green source of energy, but is also economically viable as well!