by Ivy Main, cross posted from Power for the People VA
Drill down far enough into the earth, and you will hit hot rocks. Energy companies have used this heat to generate carbon-free electricity for more than a century. It’s an elegant concept, but it worked only where pockets of heat lay close to the surface, accompanied by steam ready-made to turn turbines. Those limitations confined geothermal power plants to geologically active areas like Iceland, parts of Indonesia, and a few locations in the American West. As of 2023, geothermal energy made up less than half of 1% of U.S. electricity generation.
Suddenly, that is changing. New technology derived from oil and gas fracking methods is allowing energy companies to drill deep into the earth in places far from geologic activity. Wells can reach miles beneath the surface before branching out horizontally and creating fissures in hard, hot rock. Water injected into the wells comes back to the surface as steam to generate electricity. The steam is recaptured and re-injected to take up heat again, in a virtuous cycle powered by the earth itself.
The benefits
These “enhanced geothermal” systems can produce 24/7 baseload electricity or fill in around variable sources like wind and solar. They can even be used like batteries to store energy, including for long durations.
Unlike drilling for fossil fuels, geothermal companies avoid the shale formations that hold hydrocarbons, instead targeting non-porous rock. And since the product is not fossil fuel but steam, the technology produces zero-carbon energy without toxic or radioactive waste.
Freed from geographic limitations and using the same technology and workforce as the oil and gas industry, geothermal energy is ready to take off fast. The U.S. Department of Energy (DOE) sees it spreading across the country to provide as much as 125 gigawatts (GW) of electricity by 2050. A global estimate suggests the industry could eventually produce 4,600 GW of electricity at a cost of 50 euros (around $55) per megawatt-hour or less.
In 2022 DOE launched an “Earthshot Initiative” to reduce the cost of enhanced geothermal energy in the U.S. to $45 per megawatt-hour (MWh) by 2035. If successful, that would put it at or below the cost of any other new, dispatchable energy source.
Is this technology the answer to the surging demand for electricity from data centers and artificial intelligence? And could it allow Virginia to keep adding data centers without blowing up its climate goals?
The challenges
We do have to keep in mind that not all silver bullets prove to be sterling. Small modular nuclear reactors (SMRs) are evidence that some highly-anticipated technologies don’t follow the rosy timelines and price projections their boosters promise.
Unlike SMRs, though, enhanced geothermal systems have already achieved commercial deployment. After successfully demonstrating the technology with a 3.5 MW pilot facility, Fervo Energy signed a contract last year with Google to provide electricity for its data centers from a 115-MW enhanced geothermal power plant in Nevada. Fervo will deliver the power to the local utility, NV Energy, which will then charge a slightly higher price to Google via a proposed new “clean transition tariff.” Fervo has also signed a deal for an even bigger project that will deliver 400 MW to California utilities.
Using a different fracking-based technology it calls a “Geopressured Geothermal System,” Houston-based Sage Geosystems recently agreed to supply 150 MW of power for Meta’s data centers beginning in 2027. Sage says it can make electricity not just by extracting heat but also by using pressure, an add-on technology that allows it to offer energy storage independent of steam production.
Both Fervo and Sage say their methods can be used almost anywhere, and both cite advantages over established energy sources. Like wind and solar, geothermal is renewable and carbon-free, but it isn’t dependent on weather. It also doesn’t require fuel sources like coal and gas that are highly polluting and sometimes unreliable in extreme weather.
Finally, with a small physical footprint relative to the energy produced, geothermal facilities could be located in urban areas or next to data centers and other large customers without the need for major new transmission lines.
But of course, the fact that geothermal technology can be used anywhere does not mean it can be deployed profitably everywhere, or at least not yet. A map compiled by the National Renewable Energy Laboratory shows the most ideal areas are still in the West, where hot rocks lie within a few kilometers of the Earth’s surface. In most of the eastern U.S., deeper wells would be needed to reach the same temperatures. For this reason, DOE sees the technology proving out in the West first before spreading east.
But favorability is not purely a function of geology, according to Ben Serrurier, manager of government affairs and policy at Fervo. I wanted to know how soon geothermal systems could start providing electricity to the world’s largest concentration of data centers, in Northern Virginia. He said the biggest impediment for the industry is not location, but the high cost of capital and the paucity of government support compared to SMRs, hydrogen, and other new technologies.
In spite of these challenges, Serrurier predicted geothermal would be deployed in Virginia by the latter part of the 2030s, noting that his company is already ahead of DOE’s projected timeline for the technology’s maturation. Eastern data centers present an especially attractive market, he said, because demand is increasing so quickly, and utilities have limited options for carbon-free energy.
Alas, observers of the data center industry know that while renewable energy is nice to have, cheap energy is even nicer. So I wanted to talk about cost.
Serrurier told me Fervo’s first project will deliver power to NV Energy at a price of $107 per MWh, and Google will pay slightly more than that to the utility. That is twice DOE’s target cost for 2035, yet it still puts the price below the U.S average of 13.1 cents per kilowatt-hour ($131 per MWh) for commercial customers, and competitive with the average Nevada commercial rate of 10.92 cents, according to Energy Information Agency data.
That price is, however, more than the 9.54 cents/kWh that the average commercial customer in Virginia pays for electricity derived primarily from fossil fuels. And Fervo’s price is for drilling in the West, not in the less favorable geology of the East.
But heck, anywhere in the country, 10.7 cents for zero-carbon baseload power — with no waste to be cleaned up and no added healthcare costs from pollution — still sounds compelling. Google may have chosen to be a first mover in order to show leadership and promote a new technology, but it is also locking in a solid deal.
Sage does not make its costs public, but Lance Cook, the company’s chief technical officer, told me their process is competitive with combined cycle gas plants when the cost of fossil gas is above $6 per thousand cubic feet. (According to the Energy Information Agency, the price of gas is currently below that level in most states, though gas prices are famously volatile.)
An additional benefit, said Cook, is that a geothermal plant could be co-located with a data center, foregoing a grid connection and obviating the need for transmission lines. “We can turn electricity into data,” he told me. “It is much easier to connect data than to wait for a grid connection.”
Both Cook and Serrurier are confident that geothermal will beat new nuclear price-wise, which today sounds like a safe bet. Analysts warn that cost continues to be a significant issue for the nuclear industry. Current projections for the cost of electricity from SMRs start at $142/MWh.
Cook noted that Sage’s technology can also provide long-duration energy storage that isn’t dependent on the heat of the earth. This approach can be used anywhere to turn solar and wind power into baseload energy. Sage’s website claims it can achieve this for less than the cost of batteries or pumped hydro.
With all this promise, enhanced geothermal has been slow to catch the attention of Virginia utilities and policy-makers. The Virginia Code includes geothermal energy in its definition of renewable energy, but enhanced geothermal is not on the list of energy sources that qualify for the state’s renewable portfolio standard (RPS).
The General Assembly did pass legislation this year from Senate Majority Leader Scott Surovell, D-Fairfax, to include a similarly-named, but quite different, kind of geothermal energy – geothermal heating and cooling systems, also known as ground-source heat pumps – in the RPS. Geothermal heat pumps use the near-constant temperature of the ground just a few feet under our feet to help heat and cool buildings, much as air-source heat pumps do but with greater efficiency. A working group under the auspices of the State Corporation Commission is currently trying to figure out how to award renewable energy certificates (RECs) for a technology that does not produce electricity.
But drilling down two miles or more and generating electricity at the utility level is quite another thing. Making enhanced geothermal systems eligible for the RPS would be essential to putting the technology on an even footing with other renewables for use in Virginia.
In an email, Surovell told me, “I have read about the Google geothermal project and believe there is significant potential in Virginia.I understand it is different, but we need to do all we can to try to meet the demand for energy created by data centers without upsetting the carbon-free goals we set with the Virginia Clean Energy Act.” He added, “Geothermal also has the potential to create thousands of well-paying trade jobs in drilling and pipefitting in the Commonwealth.”
I also contacted Dominion Energy Virginia to gauge the utility’s level of interest. Dominion is facing an enormous challenge to meet the explosion of demand from data centers. Its 2023 integrated resource plan (IRP) proposed building new gas plants as early as 2028 and an SMR in 2034, but no geothermal energy. The plan failed to meet the carbon-cutting requirements of Virginia law, so the company ought to see the need to up its game for its 2024 IRP, due in October.
Dominion’s answer was not encouraging. Aaron Ruby, Dominion’s director of Virginia and offshore wind media, responded with an email that made reference to the working group for geothermal heat pump RECs.
“We’re certainly looking at the potential for geothermal in Virginia. The SCC is leading a geothermal working group, and there are lots of knowledgeable experts taking a close look. Most of the potential in Virginia appears to be geothermal heat pumps, with maybe less potential for power generation. The process is ongoing, so still more to learn.”
Echoing Gov. Glenn Youngkin’s rhetoric on energy, he added:
“As you know, we’re experiencing an unprecedented growth in power demand. Reliably serving that growth requires an ‘all of the above’ approach, including offshore wind, solar, battery storage, next generation nuclear and natural gas. Emerging technologies like clean hydrogen, longer-duration storage and geothermal could also play a role.”
It’s not a great sign that Dominion ranks geothermal dead last. The company seems quite content to keep adding data centers to its customer base with no plan to meet its climate commitments.
Data center developers, on the other hand, could vote with their metaphorical feet. If Dominion will not bring geothermal technology to Virginia data centers, maybe the data centers will go to the geothermal technology. Some data center operators say they need to be in Virginia to be close to customers in the East, but the industry’s rapid spread into other states shows many have flexibility. So why should they face public opposition and rising electricity rates in Virginia when they can go to Utah, Nevada or Texas to access low-cost, zero-carbon energy delivered 24/7 from a source that might even be located onsite?
Especially since, in so doing, they would provide the capital and demand required for enhanced geothermal to achieve DOE’s goals ahead of time, and hasten the day when Dominion presents an IRP with a real zero-carbon plan.
This article was previously published in the Virginia Mercury on September 10, 2024.