Geothermal energy—heat energy from the earth—has been used for cooking, bathing, and heating for thousands of years. In the United States, geothermal energy was initially used to heat homes in the 1890s in Idaho, and the first geothermal power plant was constructed in the early 20th century in Italy. Geothermal energy can have different applications depending on the geologic resource and technology applied, for example, electricity generation, heating and cooling buildings through geothermal heat pumps, and heating structures through direct-use applications. The question is, can geothermal energy resources be a bigger part of the solution to the world’s energy- and climate change-related needs?
In the United States, potential geothermal resources are largely in the western half of the country, with existing geothermal electricity generation occurring largely in California and Nevada. However, even in California, which views geothermal energy as part of its plan to reach its net-zero climate change goals, only 5% of electricity is currently generated via geothermal resources. Current restrictions on geothermal resources include geography and the that fact only a small portion of available geothermal energy is accessible with current technology. Also, there can be other barriers; for example, in Japan, local interests, the owners of hot spring resorts, have fought against industrial-scale geothermal energy production, with similar not-in-my-backyard opposition in the United States.
The upside of geothermal energy appears worth the effort to advance and scale this resource. The U.S. Department of Energy estimates over 100 gigawatts of geothermal capacity could be deployed by 2050 and is leading the charge, in partnership with private-sector entities, to facilitate this advance via its Energy Earthshots Initiative. The initiative seeks to tackle key remaining technical and cost challenges to reaching U.S. climate goals and, in the case of geothermal energy, reduce the costs via innovation by 90% by 2035.
Advancements will likely be focused on enhanced geothermal systems, which focus on drilling deep wells underground in hot dry rock, creating fractures to develop reservoirs, and then circulating water through the wells and reservoirs to heat the water using that underground heat. Enhanced geothermal systems may allow for the cost-effective scaling of geothermal energy, including outside traditional hydrothermal areas in the western United States, extending the geographic reach of geothermal energy.
Geothermal resources are also being used with new technologies to mitigate climate change. Direct air capture—extracting carbon dioxide (CO2) directly from the atmosphere—is viewed as necessary to meet the world’s climate change goals. Emerging direct air capture technologies and facilities leveraging geothermal resources to provide consistent CO2-free power and heat to direct air capture systems.
If the world is to meet its climate change-focused goals, innovation is key, and geothermal resources are likely to be an illustrative example of one piece of the climate change mitigation puzzle that benefits from public and private-sector investments and technological advancement. The potential benefits are too large: geothermal energy is a renewable resource, it is available in different parts of the world, and it can be applied for various uses; geothermal energy systems are baseload, meaning they provide consistent energy and are not dependent on changing factors such as the presence of wind or sun, and the geothermal industry shares many similarities with the oil and gas sector, presenting an opportunity to leverage a skilled workforce and track record of innovation. Time will tell if geothermal energy resources heat up and provide another tool to address the world’s energy and climate needs.
