Geysers show us there's plenty of heat in the earth's crust
It's currently challenging to find many issues on which Democrat and Republican politicians agree, but geothermal energy is one notable exception.
Geothermal energy harnesses natural heat from beneath the Earth's surface, and emerging technologies can now access hotter, deeper, and more diverse geothermal locations than ever before.
Generally, the low greenhouse gas emissions of geothermal plants appeal to liberals, while conservatives appreciate the increased energy independence geothermal offers, alongside the use of drilling technologies familiar from the oil and gas sectors.
Several US states are working to expedite permits for geothermal plants, and in April, bipartisan senators introduced the Next-Generation Geothermal Research and Development Act.
This legislation aims to direct the Department of Energy to support the development and commercialization of advanced geothermal energy systems.
Enhanced geothermal systems (EGS)
One emerging technology is enhanced geothermal systems (EGS), which involve hydraulically fracturing underground rock by injecting pressurized fluid into one well and extracting steam or hot water from another.
This process, commonly known as fracking, is well-known and controversial, especially in the UK, within the oil and gas industry.
"It's the same techniques and up to a point it's the same industry as well," summarizes Gernot Wagner, a climate economist at Columbia Business School in New York.
But "from a climate perspective, there's a huge difference," he adds.
Wagner believes the risk of seismic activity caused by underground fracturing is outweighed by the benefits of a renewable, continuous, and large-capacity energy source.
"Based on where we are, moving much faster, much bigger in the direction of using much more geothermal, frankly, is all good news," Wagner says.
Quaise uses concentrated millimetre-waves to vaporise rock
Advancing geothermal energy to reach deeper and hotter resources requires improvements in drilling technology.
Companies are developing drilling equipment capable of stable operation when penetrating hard rock at high temperatures.
Some firms are exploring methods to penetrate rock without conventional drills.
Quaise, a company originating from the Massachusetts Institute of Technology (MIT), employs millimetre wave drilling technology, which operates at frequencies similar to microwaves.
Harry Kelso, Quaise's communications manager, explains,
"[We are] sending electromagnetic waves in the microwave millimetre wave spectrum to essentially melt and vaporise through the rock."
Traditional geothermal energy is typically found near surface hotspots where very hot rocks are accessible.
According to Kelso,
"Millimetre wave drilling really enables you to access super-hot geothermal just about anywhere in the world."
While Quaise plans to use some conventional drilling at its Oregon project site, Kelso notes that traditional drills degrade faster when encountering very hard rock, increasing costs and drilling time due to frequent drill bit replacements.
In contrast,
"millimetre wave drilling is really what changes that because we're not using a physical drill bit," Kelso says.
Other companies are also developing advanced drilling technologies, such as projectiles capable of moving several times faster than the speed of sound.
Water use and environmental considerations
Water is a critical resource in geothermal processes. While some next-generation geothermal methods could pose risks of water contamination or excessive consumption, careful system design can mitigate these issues.
Initially, Quaise's system requires significant water input, but Kelso explains that once water enters the system, it is continuously circulated over the super-hot rocks.
"We're essentially just recycling the water over and over," he says.
Quaise is actively raising funds with the goal of having its Oregon project operational by 2030.
Economic challenges and potential
Like other early-stage geothermal projects, Quaise's initiative involves substantial upfront costs.
Kelso acknowledges,
"The economics are somewhat challenging. Geothermal today is still more expensive because you are not getting as much power out of the well as you would if you were using that well for fossil fuel."
However, Quaise aims to improve economics by targeting very high temperatures between 300°C and 500°C.
Although reaching the upper end of this temperature range is ambitious, higher temperatures mean greater energy output.
Kelso states,
"It allows you to get 10 times more energy per well from geothermal, which changes the economics and the power potential of geothermal."
Geothermal firm Fervo Energy goes public
In May, Texas-based Fervo Energy attracted significant attention by becoming the first next-generation geothermal company to be publicly traded, initially valued at approximately $7.7 billion.
Fervo expects geothermal power from its Utah plant to cost about $7,000 per kilowatt of electricity, which is more than four times the cost of solar and wind power.
Despite the premium, there is demand for geothermal electricity.
Fervo has secured an agreement to supply energy to Google, which requires substantial electricity for its new data centers.
Additionally, Fervo is supported by Breakthrough Energy, a venture founded by Microsoft co-founder Bill Gates to accelerate innovative electricity production.
Investment needs and future outlook
Such investments are crucial for next-generation geothermal companies, which face significant capital expenditures. According to the International Energy Agency, data center projects alone will not suffice to significantly expand geothermal energy.
Both customer demand and cost projections remain uncertain. The climate solutions organization Project Drawdown notes that
"early projects carry a significant risk of cost overruns."
Nonetheless, Columbia researcher Gernot Wagner believes geothermal energy holds substantial potential beyond hype.
He emphasizes that commodities like oil, gas, and coal are vulnerable to political disruptions, whereas
"geothermal is a technology" and more secure.
Wagner is confident geothermal energy has now achieved liftoff and will continue to improve and become more cost-effective over time.
