Geothermal gone wild (part 3)
This is part 3, the last chapter in our series on geothermal energy. If you missed parts 1 and 2, read them here and here.
Last week's post was all about Fervo, the Enhanced Geothermal Systems company drilling boreholes and fracking hot rocks in the Utah desert.
But they're not the only outfit attempting to harness the heat beneath our feet. Here are four more geothermal upstarts vying to save the world from within:
Quaise is melting rock with frickin’ laser beams
Quaise Energy’s approach to geothermal engineering is science-nonfiction. Following a decade of research at the MIT Plasma Science and Fusion Center, they’ve figured out how to direct high-frequency electromagnetic waves (okay, not technically laser beams) to literally melt rocks. They say their gyrotron—essentially a giant microwave—can vaporize 11.5 feet of rock an hour, which translates to one mile every 19 days.
What happens to all the vaporized rock? It turns into strands of hair-like fibers that they blow out of the tunnel with compressed air. [Dr. Evil voice] Roiiiiiight.
Despite (or because of?) the improbable nature of their technology, Quaise has raised $91 million to date. They've also demonstrated small-scale success, melting a few inches of rock for journalists earlier this year. Quaise told the WSJ they’re likely to drill their first 2.5-mile well in Oregon in 2026.
Eavor is installing underground radiators around the world
Eavor (pronounced 'ever') is a Canadian company drilling geothermal wells with a fun twist: they’ve patented a closed-loop, multi-tube system that looks not unlike the steam radiator in my living room.
The advantage of the subterranean radiator, AKA the Eavor-Loop™, is that Eaver doesn't have to frack rocks to unlock heat. Instead, a proprietary fluid flows through the intricate system, absorbing heat via conduction as it circulates, which it then returns to the surface.
Because the Eavor-Loop™ is a true closed-loop system—meaning they seal off their wellbores completely—they can ensure their fluid doesn’t find its way into the surrounding geology.
Like Fervo, Eavor is already up and running. Their first facility is a 8.2 MW plant in scenic Geretsried, Germany, which is supplying not only clean, 24/7 electricity but also ‘district heating', i.e. heating nearby homes and businesses with geothermal heat.
Speaking of district heating...
Bedrock Energy is bringing geothermal heating (and cooling!) to cities
If you supposed geothermal drilling wouldn't work in densely populated urban areas, you'd be mistaken.
A variety of novel technologies help city drillers avoid accidentally ploughing through pipes and buried power lines. Radar pulses, electromagnetic locators, precision test holes, and real-time monitoring are some of the newfangled ways drillers avoid opening up a subway car like a can of sardines.
Like Fervo, Austin-based Bedrock Energy borrows from oil and gas industry technology to drill more intelligently. Using robotic and automated drilling tech, they say they can drill boreholes up to five times faster than the industry standard, which has the benefit of reducing costs and being way less annoying for folks who live around the worksite.
Unlike the other companies we're discussing, Bedrock isn't interested in generating electricity. Instead, they're providing a very special form of heating and cooling to buildings—the most energy efficient form of heating and cooling ever devised by humans.
But first, a brief detour...
The Coefficient of Performance (COP)
New clean energy concept alert! The Coefficient of Performance, or COP, measures the efficiency of an appliance that provides heating and/or cooling, such as heat pumps, refrigerators, and A/C systems.
The formula for COP is pretty simple: divide the amount of 'useful' heat the appliance delivers or removes by the amount of 'work' or energy it needs to operate. For example, an electric resistance heater (such as a space heater) has a COP of 1: it provides an equal amount of heat to the energy it needs to work.
The higher your COP number, the more efficient your machine.
Bedrock uses something called a geothermal heat pump (also known as a ground-source heat pump) to heat and cool buildings. Heat pumps work by moving heat around, rather than generating it whole-cloth. In winter, when the temperature underground is warmer than the air above ground, they bring that underground heat up to your home. Then in summer, when the temperature below ground is cooler than the temps up above, they pump the hot air out of your house down below so it cools off, and then they pump the cooled air back upstairs.
Heat pumps are an amazing technology because they're so efficient: geo heat pumps can reach a COP of 5.5, meaning they can provide 5.5 times more heat than the energy they need to operate.
Here's a short video about how it works.
Fun fact: there are many different kinds of heat pumps! Air-source heat pumps are the most common version.
Why does efficiency matter? Because it takes a tremendous amount of energy to generate heat. Globally, heating alone accounts for nearly half of all energy consumption and 40% of energy-related carbon dioxide emissions.
As we continue the necessary work of transitioning away from fossil fuels and Electrifying Everything, the price of electricity will to continue to rise as our aging power grid comes under increasing strain. Paying 5.5 times less to heat your home will start to look more and more advantageous.
Okay, back to the program.
Sage Geosystems is turning geothermal energy into a battery
Recall from part 1 that deep underground, it’s not just the heat you have to contend with, but the pressure from all that rock sitting on top of you.
Sage is taking advantage of that pressure to turn their geothermal system into a long-duration energy storage device—better known as a battery. How it works: Sage pumps a huge volume of water into a deep underground reservoir where it can get all hot and pressurized. But instead of letting the superheated water return to the surface as soon as it’s ready to pop, they block the water's exit. The superheated water, with nowhere to go, continues to get more and more pressurized. They're effectively ‘edging’ the water, if you will.
Then, when Sage is ready to use it, they pop the top and the water bursts up, geyser-like (but contained within tubes), turning their turbine 25–50% faster than a standard geothermal system (according to Sage’s modeling).
Count Meta (formerly The Facebook) among Sage's believers: they’ve signed up for 150 MW of baseload power to supply Meta’s stupid data centers. The first phase is expected to be operational by 2027.
But why turn geothermal—already a 24/7 source of energy—into a battery?
That, my friend, is a great segue to our Q&A.
No dumb questions
If you’ve got a question about anything energy-related, I’d be delighted to research and respond. Email me: jon@greenjuice.wtf
For now, here are some questions I made up:
Q: If geothermal works 24/7, why turn it into a battery?
A: It all comes back to the Duck Curve. Solar panels only work when the sun is shining, but humans consume most of our energy at night. So in order to power our world with 100% renewables, we need to be able to store way more energy.
Energy-sucking data centers, like the ones Meta’s building, run around the clock. Grandma's got a lot of bogus news articles to comment on! That means companies like Meta are paying a premium for electricity every evening when the grid gets congested.
In theory, sure, geothermal could power Meta's whole operation without needing to turn into a giant battery. But geo isn't cheap or plentiful enough for that yet. Maybe someday! For now, the cheapest and most widely available clean power-producers are still wind and solar.
Sage is banking on the idea that data center operators don't want to cough up extra cash to pay for their nightly energy.
(While Sage is the only geothermal company I've written about dedicated to storing energy, it's worth noting that the others will likely adopt this same strategy eventually—there’s just no reason not to. Fervo’s Tim Latimer said as much during his most recent appearance on Volts.)
Q: Can we talk about earthquakes now, please?
A: Yeahhh. So, here’s what’s up: geothermal—particularly Enhanced Geothermal Systems—can induce ‘seismicity’, also known as triggering earthquakes.
Surprisingly, it's not drilling that's the culprit: it's fracking. Injecting fluids at high pressure to expand fissures in rocks can alter the stress state of the Earth's crust.
If fracking's to blame, then guess who else induces seismicity? That's right, oil and gas companies. Those guys trigger earthquakes every single day. Which is not to say it’s cool for geothermal to exacerbate the problem... but this is something that’s been going on routinely for 25 years.
Plus, there are key differences between quakes induced by geo and oil and gas:
- Induced earthquakes from geo projects are typically lower magnitude than those triggered by oil and gas activity.
- Geo projects often incorporate real-time seismic monitoring and adaptive management strategies to mitigate their risks.
- Geo projects tend to have controlled injection schedules, whereas oil and gas fracking requires a never-ending supply of pumped fluids.
Still, it's a real problem that requires careful monitoring. An EGS project in Basel, Switzerland, was canceled in 2009 after inducing a series of earthquakes, one of which reached a magnitude of 3.4. Not great!
Q: I’m still concerned about drilling so deep. Is there a chance we’re gonna unearth some weird shit, like a Balrog?
A: It's unlikely. The Earth's crust extends about 19 miles down. Nobody, to my knowledge, is planning to get anywhere close to penetrating the mantle, which is where the Balrog lives. At least not anytime soon.
However, deep drilling might just be an opportunity to unearth some of the important minerals needed to produce clean energy technology. When pumped water returns to the surface after circulating underground, it comes back as 'geothermal brine', a mixture of water and rock guts. This brine could become a significant source of lithium and other critical elements, like copper and cobalt.
Mining for minerals is a hairy topic. I plan to write about it in depth, but the short version is that we need critical minerals to transition from fossil fuels to renewable forms of energy... and yet much of the mining that takes around the world—particularly in places like the Democratic Republic of Congo, which holds vast cobalt reserves—is a humanitarian and ecological nightmare.
Any mineral production derived from stateside geothermal projects seems to me like a good thing.
Q: Okay, I'm convinced geothermal engineering has merit. But will the Trump administration kill off all these projects?
A: [protracted sigh] Yeah, probably. Which is so unbelievably fucking stupid. Of all the clean energy technologies, geothermal has perhaps the most bipartisan appeal: it's American-made, it's far less reliant on Chinese manufacturing than solar and wind, and it creates a natural transition industry for oil and gas workers.
Yet at this very moment, Trump and his sicko-phants are trying to gut the tax credits from Biden's Inflation Reduction Act, the biggest climate bill ever passed in American history. Doing so would effectively halt any new advanced geothermal projects from securing financing.
Canary Media has a helpful writeup of what's going on, and what's at stake for geothermal (and nuclear).
Here on Green Juice, we try to maintain a positive outlook. But these are terrifying times. Climate change is dropping tornados and summoning heat waves all over the country. We can't wait four more years to take action.
If there's a silver lining, it's that some Republicans are pushing back on these tax cuts, which will disproportionately impact red states where EV factories and battery plants were just starting to gain momentum. If you have Republican representatives, please give them a call this week and say we need to keep the IRA tax credits. They need any encouragement we can muster.
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