"Geothermal and Solar; One and the Same" (Green Build)
If you look at a comparison of energy inputs received by Earth (chart above), you can easily see the overwhelming presence of solar energy. Half of Earth’s incoming solar energy is absorbed by the Earth’s surface. When you look a little further, below the ground, you can see some seasonal variations for the first 50 feet, and then the temperature stabilizes and remains constant until we reach a depth at which the temperature starts increasing incrementally. This is the temperature increase that is the source for “hot-geothermal” resources, though it doesn’t have a real impact until about 1000’.
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