Renewable power is frequently criticized for its unreliability, which some feel makes it difficult to use for base-load power generation. Of course, renewable systems usually face huge up-front costs, which makes their implementation difficult and which makes some argue against their use. Geothermal power may be able to jump start its presence in the renewable power field by overcoming one of its biggest expenses: the boring of holes into the earth.
Wind power and tidal power systems can be variable depending on the weather. Lull periods can limit the amount of power wind farms can generate, although regular shifting of coastal winds makes near shore and off-shore Solar energy is quite reliable, since the rising and setting of the sun is predictable and well understod, and solar power generation is increasingly less dependent on cloudless skies. Geothermal energy is the renewable energy option that is probably least susceptible to unpredictability.
One of the largest expenses in geothermal power systems is boring wells thousands of feet into the earth's crust. Now, several companies are looking at reusing existing and abandoned oil wells to serve as geothermal wells. Particularly in Texas, where there are more than half a million existing oil and gas wells, and underground temperatures and pressures are high enough to make geothermal energy extraction feasible, geothermal is getting a fresh look by a number of companies.
Deep oil wells are often far enough into the earth that they reach to areas with temperatures as high as 300 degrees F (about 150 degrees C), or even higher, which can be useful for geothermal uses. And we are proponents of recycling, even if it is finding a new use for the old fossil infrastructure for renewable power. "While each well only produces enough energy for a few hundred homes at best, connect several wells on a single acre and it can add up." A field of several wells also makes it cost effective to build the generating infrastructure that a geothermal power system would need.
image via Wikimedia Commons