What is Geothermal Energy?
Geothermal heat is naturally generated deep below the earth’s surface. This heat is the world’s largest source of continuous renewable energy. With at least an order of magnitude more energy than coal, oil, and gas combined, geothermal can scale to accelerate the transition from fossil fuels to renewable energy.1 Equally important, geothermal projects supply renewable power around the clock, emits little or no greenhouse gases, and have the smallest footprint per unit of output than any alternative renewable energy technology.
Geothermal energy can be used in a variety of ways. The most prevalent application for high temperature geothermal is generating clean, renewable electric power. Other applications are being developed for hydrogen production, lithium extraction, and heat or power intensive industrial applications. Low temperature geothermal energy can be used for heating buildings, greenhouses, and other structures.
Paradoxically, geothermal energy is greatly underutilized, comprising only about 1% of the U.S. energy portfolio. The enormous disparity between the geothermal power potential and usage is due to the physical limitations of conventional geothermal power that constrain development to roughly 2% of heat resources that are found in highly permeable subsurface formations.2 Additionally, the industry is hobbled by a difficult business model characterized by long time frames and high risk as globally 22% of drilled wells are unproductive at the outset or over time.
U.S. Department of Energy3
Geothermal Energy Benefits
Renewable
Geothermal energy is renewable because its source is the heat which is naturally and continuously produced in the sub-surface of the earth.
Abundant
Geothermal energy is the world’s largest potential source of continuous renewable energy with at least an order of magnitude more than coal, oil and gas combined.3 It is estimated that 70% of overall geothermal resources are yet to be discovered.4
Continuous
Geothermal power plants are inherently “always on,” unlike intermittent solar and wind projects. Continuous energy is important for grid stability and applications that require on-demand usage.
Clean
Geothermal energy produces little greenhouse gases. Specifically, closed-loop geothermal has no greenhouse gas emissions and protects the quality of subsurface water.
Available
Geothermal resources can be found in many areas of the world, particularly along major tectonic plate boundaries where most volcanoes are located. The western U.S. (California, Alaska, Hawaii), the Caribbean, El Salvador, Mexico, the Caribbean, Costa Rica, Australia, Japan, Indonesia, New Zealand, Philippines, Turkey, and parts of Europe have working geothermal plants.
Small Footprint
Geothermal has a small footprint per unit of energy output. Specifically, closed-loop geothermal has the smallest footprint per unit of energy output than any alternative renewable energy.