The Weekend Wonk: Today’s Geothermal Renaissance

March 12, 2022

Reinventing oil and gas skills and technology to provide a limitless source of clean, zero-carbon energy.

Increasingly in talking to smart energy experts, I am hearing the words “geothermal”, “dark horse” and “sleeper” used together, as in my talk with U of Texas’ Michael Webber, here.

We won’t get out of this jam if we can’t recruit the people that know best how to build big energy at scale, as Saul Griffith notes below, and that’s the existing energy industry. We know that there are a lot of people in the industry that feel trapped and are looking for a way forward. That just might be happening right now.

Michael Webber on Twitter:

I’m making a list of energy options for the power sector whose availabilities vary w/ the weather and those that don’t:

Weather-dependent:
Natural Gas
Coal & Biomass
Nuclear
Wind
Solar
Hydro

Not Weather-dependent:
Geothermal
Tidal 
Fuel Oil & Diesel

What did I miss? 

Geothermal is the only option for the power sector I can think of that is:

Available 24/7
Doesn’t depend on the weather
Is low-carbon

It also leverages a lot of know-how from the O&G sector.

Seems like a global opportunity waiting to happen. 

Oops. One more 24/7 option that is low-carbon…

Efficiency! 

Should’ve started with that one. 

Natural gas can fail if it gets too cold.

Coal & Biomass can fail if the piles of fuel freeze or get soaked or if there is a drought that limits the cooling water.

Nuclear can fail b/c of flood, freezes, heat waves or drought. 

Wind availability changes with diurnal and seasonal air flow patterns.

Solar availability changes with level of cloud cover and astronomical conditions like position of the earth relative to the sun.

Hydro changes with rainfall, snowmelt and evaporation. 

Tidal: Gravity doesn’t change w/the weather.

Geothermal: The heat of the earth doesn’t change w/the weather (works in hot Hawaii and cold Iceland).

Fuel oil and Diesel: Often used as back-up for gas and coal (esp. w/air-cooled turbines or gensets).

A reliable grid needs a mix. 

So, if we care about…

1) renewability
2) reliability despite weather
3) low emissions
4) affordability (e.g. immunity from oil/gas price spikes)
5) security (e.g. immunity from fuel supply cutoffs)
6) 24/7 dispatchability

…then geothermal is at the top of the list.🌎🔥 

New Atlas:

Quaise’s ultra-deep geothermal power plan is one of the most exciting and fascinating green energy projects we’ve seen. In a nutshell, this Boston-based MIT spin-off says it has repurposed powerful millimeter-wave beam technology – originally developed to superheat plasma in fusion experiments – to blast through previously undrillable rock far below the Earth’s surface.

The company says this will allow it to drill bore holes far deeper than has ever previously been possible, going down far enough to access rock temperatures around 500 °C (932 °F). That’s well past the point where water becomes heated to a “supercritical” state that radically boosts the efficiency of geothermal power extraction.

The end result: massive, virtually inexhaustible geothermal energy resources will become available practically anywhere on the planet. More or less any existing power station that uses fossil-fueled heat to create steam and run turbines can be connected to a totally reliable, 24-hour supply of green energy that’ll keep those turbines turning without a single puff of CO2 escaping, and without the worrying intermittency of other renewable sources like wind and solar energy.

It’ll be surprisingly quick, too. The deepest hole humanity has ever drilled to date took nearly 20 years to reach a depth of 12,289 m (40,318 ft), but Quaise says its hybrid drilling rig – using a traditional rotary bit to get through the easy stuff and a gyrotron-powered energy beam to melt, fracture and vaporize the tough stuff – will take just 100 days to deliver you a hole 20 km (12.4 miles) deep. Three and a bit months gets you a long-term green energy supply, in a stable bore hole lined with glassy melted rock, wherever you want it.

So we’ve collected the best – and a few of the worst – questions from both these sources, and put them to Quaise CEO and co-founder Carlos Araque, who was kind enough to get back to us. His lightly edited responses are reproduced below.

Could an earthquake cut off the bore and disable the power station? 
Unlikely. Earthquakes rarely disrupt oil and gas wells. These are similar but 3-5x deeper.

How long can these ultra-deep shafts be expected to last?
50-100 years.

Does rock not flow at the temperatures and pressures expected at these depths?
Rock does not do this until you get to the mantle, which is much deeper than what we are doing.

Will a flow of supercritical water provide enough pressure to keep the bore open? 
It helps; the bore is vitrified as byproduct of the drilling process and the rock is very competent at those depths, which also helps.

During the directed energy boring process, is it possible for water to enter the bore? 
It is possible, but the rock is very impermeable at those depths and the flow rate would be low; any water that enters the wellbore instantly vaporizes.

Could this water be superheated by the mm wave beam, causing high-pressure steam that might damage the equipment? 
It will get superheated, but there is nothing to damage. The only downhole equipment is a pipe.

Is it possible that drilling this deep might release magma, effectively creating a man-made volcano? As one commenter put it, “Let’s see what happens when you pop the biggest zit in our solar system.”
This cannot happen. Any magma that comes into such a small hole would solidify in the first few meters. Humans have already done this multiple times, and this is exactly what happens.

If this solution is deployed at scale, could it be possible for the heat released from under the surface to contribute to global warming? 
The Earth already leaks 40 TW from within, whether we exist or not. Humanity uses 20 TW, so no.

Could this idea be economically adapted into shallower 1-2-km (0.6-1.2-mile) holes simply to provide warm water for hydronic heating and other purposes? 
Certainly, we intend to do that too. This is not just about 20 km; there is plenty of value to unlock starting at 100-meter deep holes.

Is there a possibility that deep drilling of this nature might lead to seismic events similar to what’s been observed with fracking? 
Drilling and fracking are different processes. Drilling does not cause seismicity.

Would a millimeter wave beam potentially ignite a pocket of natural gas if it encountered one on the way down?
Gas is located in sedimentary rock. We drill the sedimentary rock using conventional technologies.

Could pulling heat out of the Earth’s core cause excessive global cooling, disrupt the core convection currents or affect the magnetic field? 
See the comment on the 40 TW above.

Would it not be cheaper and easier just to access geothermal heat reserves closer to the surface?
Of course; it would also be easier to just access wind and solar. The problem is that there is not enough of it to power the civilization we have created with fossil fuels.

Is the supercritically heated water likely to be highly corrosive to the above-ground equipment?
Yes, but there are many supercritical power stations in use today. The materials exist to handle it.

Couldn’t you just drill into the side of a volcano instead?
Yes, but most humans do not live near one. This is a solution that can work for 95 percent of humanity.

Isn’t that how planet Krypton was destroyed?
No, an explosion destroyed Krypton.

Do you guys not watch disaster movies?
We love them! This is precisely why we need to do this: to avoid a disaster.

Could this unleash the lizard people that inhabit the inner sphere?
How do we know they did not already drill up using this technology and are already amongst us?

Will you be renting out the megawatt-class energy weapon between projects? One user wants to keep it in the car for when people cut him off on the freeway.
No.

Will this wake up the Kaiju?
No.

11 Responses to “The Weekend Wonk: Today’s Geothermal Renaissance”

  1. rhymeswithgoalie Says:

    Is the supercritically heated water likely to be highly corrosive to the above-ground equipment?
    “Yes, but there are many supercritical power stations in use today. The materials exist to handle it.”

    Yes, there is plumbing de$igned for this type of application with a harsh hot, corrosive environment. People know how to do this, it’s just a matter of making the extra capital costs worth it.

  2. rhymeswithgoalie Says:

    Nerd note: I remember from all that geology I took at UT after I retired a research talk about how pushing fluids through fractures changed the chemistry along the sides of that rock (he called them “skins”). Some of the reactions opened or did not affect the size of the fracture, but others tend to form substances that built up in the fracture. That’s why I’m dubious of the lifespan of the heating model that just pushes fluid through fracked rock rather than one with a protected path where the fluid is not in contact with the native rock.

    [Of course, many of you are already familiar with scale buildup from “hard” water at surface temperature and pressure:

    Roman-built aqueduct Euskirchen Kreuzweingarten:

  3. indy222 Says:

    This is on my short list of promising new energy tech…. but I have another worry; how high can the heat-rate be out of these? Conduction is a slow process. Once you’ve gotten heat out of the meter or two of rock immediately next to your bore hole, you’ve got a temperature gradient between hotter rock farther from the bore hole and the bore hole. In soil, just a few meters is enough to insulate all ground beneath it from all the heating and cooling changes from diurnal and seasons both.

    It’s not the quantity of heat that’s the problem (yes, it’s pretty much inexhaustible), it’s the rate at which you can pull it, given the thermodynamics of conduction. On your next go’round, Peter, you should ask that question.

    • rhymeswithgoalie Says:

      Definitely looks like a major issue to me. This would be roughly analogous to the “cone of depression” around a water well. As the pass-through sucks heat out of the hot rock, to pick up more heat you’d have to slow the rate your fluid runs through it.

      • J4Zonian Says:

        They do give out after a while. Start a new hole and give up on the old one for a while, come back to it in a few years. I have no idea how long it would take to replenish itself under various geological conditions, but might need a number of sites in an area to rotate between to provide power essentially forever.

        Not to change the subject a couple of times but:

        1. 24/7 is easy now, with PV, offshore, even onshore wind. Any of them could do it with 2 4-hour batteries in series, each battery equal in MW to the power source MW; or CSP with salt storage. It’s 24/7/~300+ that gets hard. That takes diverse sources, distributed generation, demand response, and hugely-rampable dispatchable sources.

        2. Thinking we can “make peace” with the far right aligned with the fossil fuel oligarchy is dangerously naive. Opposition to awareness of climate catastrophe, to the solutions to it, to any moves to prevent the end of civilization and nature, isn’t about money, or fossil fuels, though burning things and breaking or fusing atoms in big containers is a symptom. It’s about the addiction of the right to power, domination, and destruction, including the nihilistic destruction of everything.

        You can never get enough of the wrong thing
        Because they’re trying to fix their own past by exerting more control in the present, they’ll never be satisfied with anything but an amount of control that’s impossible, and the only non-unsatisfying alternative is destruction of everything. The oligarchy has no empathy and there’s nothing we can give that will satisfy them without destroying everything. The only way forward to survival is to remove them from power and replace them with sane people.

        • indy222 Says:

          I agree J4, they’re trying to fill a psychological hole blown in their soul with the wrong mix of “solutions”. There’s amplifying feedbacks everywhere, including in bad psycho-evasions. It either ends in suicide, or in megalomania, or if somehow they luck out, or end up more terrified of suicide than facing up, the “hit bottom” and start to bounce. But to do that enmass for the party? I agree that’s unlikely. They’ve made their Faustian bargain and it’s pay up time.

  4. J4Zonian Says:

    “it would also be easier to just access wind and solar. The problem is that there is not enough of it to power the civilization we have created with fossil fuels.”

    Not sure about that one. Does that “not enough of” refer to reg’lar geothermal? or wind and solar? There’s plenty of offshore wind power to supply all we need many times over, and of course it increases as the technology improves. There’s also more than enough onshore wind, and thousands of times more solar than we need. There’s plenty of reg’lar geothermal to complement the easier, cheaper wind and solar, existing hydro, and small amounts of dispatchable bioenergy, and it’s not just a few places, as Beard says. (She must know that; why lie except to manipulate people into accepting her type of geothermal?). The Ring of Fire touches a lot of countries including some of the most energy-intensive and populous ones—Japan, Canada, US, China, Indonesia…

    But the first place most people think of when they think of geothermal is thousands of miles from the Ring of Fire—Iceland. And Kenya, which almost no one thinks of, has a 44% geothermal grid. (Also 36% hydro, 11% wind, with LOTS more solar & wind potential.

  5. indy222 Says:

    Deep geothermal does satisfy my own 2 safety criteria:

    1. Don’t take the Earth System through hysteresis in trying to get back to a good climate state.

    2. Leave the surface of the Earth as pristine as possible.

    By lowering CO2 burning and leaving the surface alone, those are both good things.


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