What does “geothermal” mean?
“Geo” means “earth” and “thermal” refers to heat, so essentially we are talking about the heat of the earth. In most places the underground (below 4-6 feet) temperature remains consistent all year long. This is why some animals like to live in burrows under the ground – it helps to keep them cooler in the summer and warmer in the winter. Depending on latitude, ground temperatures range from 45°F (7°C) to 75°F (21°C). The kind of geothermal energy that individual homes and businesses use takes advantage of this fact.
NOTE: Some places, particularly where volcanoes occur or on the Pacific “Ring of Fire” (at the edge of continents) may have hot springs, steam vents (fumaroles), and geysers that can be a source of very hot (up to 500° F (260°C)) water or steam. This can be harnessed to generate electricity, often for many people via a geothermal power plant. While this exciting source of power is already being used in various places around the world, it is not applicable to individual dwellings.