Geothermal for Power Generation

Michelle Heath April 9, 2021

Geothermal Series:

For Heat | For Power

Geothermal power plants convert heat to electricity by using hot water below the earth’s surface to rotate turbines and start a generator that produces electricity.

Direct Use – 284 TWh – Heating and heat pumps.

Indirect Use – 92 TWh – Converting the heat power to electricity prior to utilization.

Unlike other renewables such as wind and solar, geothermal is available 24 hours a day.

The global market for geothermal electric power plants is expected to grow from $US 1.4 billion in 2019 to $US1.7 billion by 2025.

Installed geothermal indirect-use capacity is gradually increasing, globally reaching 15.6 gigawatts in 2020, 24% of which is in the United States.

Estimated growth of geothermal electricity generation in 2019 was 3%. According to the IEA, to reach their Sustainable Development Scenario projections would require a 11% annual increase in geothermal power generation.

A study on emissions published by the World Bank showed that while the average geothermal plant produces less emissions than traditional fossil fuels (122 gCO2/kWh), many produce more (up to 1,300 gCO2/kWh), depending on the reservoir being exploited.

The long-term environmental impacts will depend on the new reservoirs exploited and their levels of greenhouse gas concentrations as well as assurance that the effects of geothermal exploration and development are mitigated.

Abbreviations:

EIA – U.S. Energy Information Administration

IRENA – International Renewable Energy Agency

CAGR – compound annual growth rate

LCOE – levelized cost of energy

GWh – Gigawatt hours; unit of energy representing one billion watt hours or one million kilowatt hours; 1 GWh = 1000 MWh

MWt – Megawatts thermal; power input equal to a million watts

TJ – Terajoule; unit of energy equal to a trillion joules

Sources:

http://www.history.alberta.ca/energyheritage/energy/alternative-energy/geothermal-energy/geothermal-energy-throughout-the-ages.aspx

https://www.geothermal-energy.org/pdf/IGAstandard/WGC/2020/01018.pdf

https://www.wbdg.org/resources/geothermal-energy-direct-use