Humanity’s quest to tap into the inexhaustible power source lying beneath our feet has spanned millennia, with civilizations from ancient Rome to Aboriginal Australia attempting to harness power from the Earth’s core. Geothermal energy — derived from sources like volcanoes in Iceland and hot springs in the United States — presents vast opportunities for electricity production.

However, despite its long history and potential benefits, geothermal power remains largely untapped. In the United States, only a fraction of the nation’s energy — about 1.5% — is sourced from geothermal reservoirs.

“Researchers from the National Renewable Energy Laboratory claimed that every house in the U.S. could be heated from geothermal sources for millennia,” theoretical physicist Sabine Hossenfelder said. “This sounds good, but in reality, geothermal energy presently plays a small role in most places on Earth.”

The Biden administration is hoping to change this by investing over $200 million in various initiatives aimed at expanding and enhancing geothermal energy systems domestically. The administration’s goal is to leverage this technology to power over 40 million American homes, constituting more than a quarter of the nation’s households.

“Geothermal runs day and night, and so with the right investments and incentives, we can increase the power that we generate from the heat beneath our feet 47 fold by 2050,” U.S. Energy Secretary Jennifer Granholm said. “Now, that is enough to power Texas 12 times over.”

One of the advantages of geothermal energy is its affordability for consumers. Geothermal energy costs roughly half as much compared to nuclear power, while also outperforming coal in terms of cost-effectiveness and environmental impact. The Department of Energy hailed geothermal power as a “clean energy source,” emitting only excess steam and minimal amounts of gas, thereby significantly reducing carbon emissions compared to fossil fuels.

Despite its environmental and economic advantages, the widespread adoption of geothermal energy will still be a challenge. The primary hurdle lies in the high upfront costs for developers, with geothermal plants being up to 10 times more expensive to construct than solar or wind farms.

The process of extracting geothermal energy, particularly through flash steam power plants, entails drilling miles deep into the Earth’s crust, which can be time-consuming and capital-intensive. In some cases, developers will have to wait as long as a decade before the plant can get up and running to produce revenue.

“Once the [geothermal power plant] is firmly developed and everything is running well, it is definitely a cash cow — you are making money left and right,” Gerald W. Huttrer, a geothermal geologist and consultant said. “But it takes a long time and people are impatient.”

The accessibility of geothermal resources varies across different regions, leading to higher land costs in areas suitable for geothermal power plants. These plots of land for larger scale operations can be worth tens of millions alone.

Nonetheless, the federal government’s recent investments in this sector signal a significant commitment to expanding renewable energy sources. In the past year, the United States emerged as the leading producer of geothermal energy globally, with continued investment trends likely to unlock even more of the Earth’s subterranean energy potential in the near future.