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Between Hot Rocks and Hard Places
The Slow Climb of Conventional Geothermal in a Rapid Renewable Age
Conventional geothermal electrical generation, where conditions are right, is an excellent form of renewable generation. It keeps chugging along day and night, offering firmed power with some of the highest capacity factors in the business and very low emissions per MWh. Yet, despite its many advantages, geothermal often gets left out of the clean energy conversation. Let’s dig into this a bit.
As a note, this is one in a series of articles on geothermal. The scope of the series is outlined in the introductory piece. If your interest area or concern isn’t reflected in the introductory piece, please leave a comment.
Geothermal power plants don’t rely on burning fuel. Instead, they tap into the Earth’s natural heat to generate steam, which then spins a turbine to produce electricity. Simple in theory, but not all geothermal plants are created equal.
The most common design is the flash steam plant, which pulls up high-pressure hot water from underground reservoirs. As the pressure drops, some of the water “flashes” into steam, which is then routed through a turbine to generate electricity. If there’s still enough heat left after the first flash, the remaining water can be flashed again in a double-flash…