Is Geothermal Poised for Breakout?

November 2, 2020

Cool thing about Geothermal – it calls for similar areas of expertise to oil drillers and service industries. With those industries now on the ropes, oil drillers and the industries that service them are looking for new frontiers. Geothermal would be one, along with offshore wind (experience building large floating platforms a plus…)

A lot of the workers I met working on a large wind project here in Michigan over the summer had a background in Oil & Gas – including the phenomenal heavy equipment operators, who wrangle hundred ton towers and blades with surgical precision.

First, be aware that Dave Roberts has written a nice round-up on geothermal for Vox, worth bookmarking.

Below, a newer variation on Geothermal, brought to my attention by a reader.


Geothermal power is the perpetual also-ran of renewable energy, chugging along in the background for decades, never quite breaking out of its little niche, forever causing energy experts to say, “Oh, yeah, geothermal … what’s up with that?” 

Well, after approximately 15 years of reporting on energy, I finally took the time to do a deep dive into geothermal and I am here to report: This is a great time to start paying attention! 

After many years of failure to launch, new companies and technologies have brought geothermal out of its doldrums, to the point that it may finally be ready to scale up and become a major player in clean energy. In fact, if its more enthusiastic backers are correct, geothermal may hold the key to making 100 percent clean electricity available to everyone in the world. And as a bonus, it’s an opportunity for the struggling oil and gas industry to put its capital and skills to work on something that won’t degrade the planet. 

Vik Rao, former chief technology officer at Halliburton, the oil field service giant, recently told the geothermal blog Heat Beat, “geothermal is no longer a niche play. It’s scalable, potentially in a highly material way. Scalability gets the attention of the [oil services] industry.”

A wrinkle on Geothermal getting attention, especially interesting with Michael Liebreich, founder of Bloomberg New Energy Finance (BNEF) on board.

Recharge News:

The holy grail of the energy sector has long been to produce endless electricity through nuclear fusion, effectively harnessing the power of the Sun here on Earth.

But while nuclear fusion always seems 20-30 years away, similar results can be achieved with existing technology by harnessing the heat emanating from the Earth’s 6,000°C molten core, according to a Canadian start-up.

Eavor (pronounced ‘ever’) believes it will be able to provide gigawatts of baseload and dispatchable renewable energy anywhere in the world for less than $50/MWh by the end of the decade, making its technology cost-competitive with natural gas and coal. And it has already proven its concepts in a pilot project, Eavor-Lite, that has been operating in Alberta, Canada, since last December.

The three-year-old company’s Eavor-Loop solution might sound like pie in the sky — chief executive John Redfern tells Recharge he initially thought it was “the dumbest idea I’d ever heard” (see panel below) — but it is a remarkably simple concept.

Drill a deep hole anywhere on the planet and the temperature will rise about 30°C every kilometre down. In certain volcanic hotspots, temperature gradients reach 60°C or more per kilometre. So drill to a depth of 3-5km — as the oil & gas industry sometimes does — and the temperature of the rock will potentially be hundreds of degrees Celsius. Water poured into such a hole, or produced from that hole, would immediately turn to steam — a resource that can turn electricity-generating turbines.

Now what if the hole wasn’t a hole, but a closed loop in which cold water — or a similarly behaving working fluid — travels down a 3-5km pipe, then underground horizontally for a few kilometres, up another pipe and along the surface back to the start?

Not only would such a loop generate constant energy, but the cycle would essentially power itself due to thermodynamics. As cold water is denser than hot water, it effectively pushes hot water towards the surface. In a pressurised self-contained loop where cold water is constantly heated underground and the heat is extracted at the surface via off-the-shelf organic Rankine cycle turbines, the liquid will constantly circulate without the need for a pump — a phenomenon known as a thermosiphon.

“We know this thermosiphon works, it’s classical thermodynamics,” Redfern tells Recharge. “But for many it seemed somewhat counterintuitive as if it’s some sort of perpetual motion machine.”

Adjusting the pressure inside the loop using a valve on the surface can change the speed of the cycle, and thus raise or lower the electricity output, converting a baseload system into a dispatchable one that is able to generate energy on demand, according to the power and balancing needs of the local grid.

Eavor says it can build self-contained, scalable Eavor-Loops using tried and tested drilling techniques from the oil & gas sector — alongside some of its own patented or patent-pending innovations — to enable endless renewable energy from the Earth at market-competitive prices.

The technology is now ready for commercial deployment, says Redfern, who adds it has already attracted the attention of governments, oil companies and municipalities around the world.

“The fact that of all the green scalable solutions, it’s the only dispatchable one means that it’s pretty hard to imagine a future where it wouldn’t make sense for at least a good segment of [future] power to come from this [technology], the same way you’d expect wind, solar and gas and storage to be part of it.

“It can certainly play a key role [in the energy transition].”

Michael Liebreich, the founder of Bloomberg New Energy Finance, who is chairman of Eavor’s advisory board, tells Recharge: “It would be as pretty damn close to the holy grail as you can get… if it can be done at an affordable price.
In the early days of Eavor, “one of the things that was a mystery to us were the oil & gas companies. We always thought the industry is looking to transition. Here’s a green solution that ostensibly is based on all their skillsets. Why the hell wouldn’t they be interested?’ And in fact, initially none of them were — they’d all written off [geothermal] five to 10 years before. And the reason was because none of them found it to be scalable.

“But now they’re starting to get interested in it. The other people who are interested in it are the political class because what is one of the big difficulties of the energy transition? It’s what do you do with all the skills and assets and knowhow that is there in the oil & gas industry?

“You can’t tell everyone to go and install solar panels, that doesn’t work, that doesn’t support the standard of living that they’re used to. So in places like Texas and Alberta, of course there has been some resistance — no one wants to be a turkey voting for Christmas.

“But this gives them this window where the very skills they’ve honed in oil & gas, those drilling rigs and geological knowledge, the ability to do a lot of these subsurface resource plays at scale, all these types of skills and assets can potentially be redeployed on this. It’s the one green technology that North America could actually lead the world in. So, you know, how is that not political catnip?”

More here.

10 Responses to “Is Geothermal Poised for Breakout?”

  1. Keith McClary Says:

    15 September 2010
    Drilling 10,000 m deep geothermal wells

    “I believe we can develop the knowledge we need about materials to get down to 300°C in 10 years’ time. It might take 25 years or more of research and development to get down to 500°C.”

    The Vox article says: “Directional drilling in high temperatures, above 150°C or so, remains difficult …”

    renewableenergyfocus also says: “The normal lifespan for a deep geothermal well is around 30 years, after which the rock has cooled down too much from the cold water injected into the well. However, if left for 25-30 years, the geothermal well will have heated up again.”

  2. grindupbaker Says:

    If humans ever produce >36% of their present energy (but assuming a great efficiency to 80% for all-electric energy) from geothermal then they’ll be using more geothermal heat than gets to the surface from all volcanoes on Earth including the postulated few million undersea ones. That’ll be an achievement by itself and might shut up the “it’s volcanoes doing the heating” crowd, probably not.

  3. Brent Jensen-Schmidt Says:

    Some years ago was contracted to geophysicaly map and prognose geothermal wells, 6 km deep into hot granite at 300 deg c. Great job including getting paid. Still in all conscience had to point out this would be a ‘trifle’ problematic. This was poo poohed, and what the hell, it might work. Result is about half a dozen holes, a non remediated power line for not one erg transmitted. Wish persons above all the best, and it is not a solution until it works. The difficulties are in the situation, not the technology.

  4. neilrieck Says:

    You do not need to go that deep. The ground never freezes more than a meter/yard below the surface making it a good source to extract heat. It also never gets too hot making it a better sink (than hot air) as a destination for cooling.

    • mboli Says:

      You are talking about ground source heat pumps. These use electricity, they don’t generate electricity.

      This article is about utility scale electricity generation. They use heat from the earth to generate electricity.

      The heat pump moves heat from the ground into a house, pushing geothermal heat from the colder ground into warmer house. It is the opposite of the direction the heat naturally flows. Pumping heat in the wrong direction takes energy.

      The geothermal generating station moves heat from the hot far-underground into the cooler air. This is the direction the heat naturally flows, if you can get the hot stuff up from underground. When heat flows in the right direction, you can turn some of that heat flow into electricity.

    • J4Zonian Says:

      Technically that’s not so much geothermal as solar using the earth as storage.

  5. Linda Foss Says:

    We have hot, pressurized reservoirs of brine all along the Gulf Coast with thousands of abandoned oil wells already drilled into it. This was investigated and demonstrated by the DOE decades ago, then dropped in favor of the petrochemical industry. This is Green Power 24/7 produced right where the cities are located that could employ oil industry workers, not displace them.

    Also, rare earth minerals can be extracted from the brine.

  6. Richard Muller has a few pages about geothermal in his book, Energy for Future Presidents, that is very enlightening as to the limits of geothermal. He first does a comparison of the amount (44 terawatts) and concentration (0.1 watt/m**2) of the Earth’s geothermal energy (generated mostly by radioactive decay) with solar (average of 250 watt/m**2). He also points out that heat moves very slowly through rock, meaning that once a lot of geothermal heat has been extracted from an area, it takes eons for it to be heated up again. There are also factors of efficiently extracting geothermal heat. Geothermal heat is not distributed evenly over the Earth, so there are some places with high concentrations that make sense, like Iceland.

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