What is geothermal energy?
Geothermal energy is energy that is harvested from heat within the Earth. The majority of this heat comes from the decay of radioactive isotopes beneath the Earth's surface, especially potassium-40 and thorium-232. Relevantly, if this heat comes into contact with water, the steam generated can be used to produce electricity. Places with large and easily accessible bodies of geothermally heated water are those most suited for the energy type: Iceland is known for using its volcanic landscape to great effect. Otherwise, more effort is needed, as drilling towards heat sources will be necessary. Due to the consistency of heating processes within the Earth, geothermal is quite reliable.
Heat pumps
Smaller pockets of geothermal energy are not always useful for the generation of electricity. However, such pockets are commonly found within a few hundred feet under the Earth's surface. We may use this low-temperature energy to heat homes and use in industrial processes. By creating an underground loop system, warming air as it moves through, a building may no longer need to use much if any grid energy for heating. The Environmental Protection Agency states that geothermal heating is the most energy efficient and environmentally safe heating system currently available. When the University of Indiana swapped coal boilers for heat pumps, for example, they saved $2 million per year on energy costs.
Geothermal energy production by nation
Rows of data: 3
| Country | Continent | Production (gigawatts) |
|---|---|---|
| United States | North America | 3.7 |
| Indonesia | Asia | 2.3 |
| Philippines | Asia | 1.9 |
| Turkey | Asia | 1.7 |
| New Zealand | Oceania | 1 |