[Scott] Coming up on "Energy Switch," we'll look at geothermal energy.

- The resource is truly everywhere, so it's not a resource uncertainty, like there is with oil and gas, there's always heat, but the technological gap prevents us from getting to it.

- I can't state how dramatic the impacts of full-scale geothermal heat pump deployment would be on the grid.

The cost savings are on the order of billions of dollars, and then the emissions reductions are just as incredible, you know, millions of tons of CO2.

- With no new technology required.

[Scott] Next on "Energy Switch," what's new in geothermal.

[Narrator] Funding for "Energy Switch" was provided in part by the University of Texas at Austin, leading research in energy and the environment for a better tomorrow.

What starts here changes the world.

And by EarthX, an international nonprofit working towards a more sustainable future.

See more at earthx.org.

[upbeat music] - I'm Scott Tinker, and I'm an energy scientist.

I work in the field, lead research, speak around the world, write articles, and make films about energy.

This show brings together leading experts on vital topics in energy and climate.

They may have different perspectives, but my goal is to learn, and illuminate, and bring diverging views together towards solutions.

Welcome to the "Energy Switch."

Geothermal, literally the heat of the Earth, can be found everywhere below the surface at varying temperatures, depending on how deep and where you are.

We can use it to warm homes and buildings, to generate electricity, and hopefully, in the future, to produce high heat for industrial processes.

There are difficult challenges to some of these, but others are surprisingly within our reach.

We'll talk about this with Lauren Boyd, is a 15-year veteran of the U.S. Department of Energy, where she's the acting director of the Geothermal Technologies Office and the enhanced geothermal program manager.

Carlos Araque is the co-founder and CEO of Quaise Energy, an advanced geothermal energy startup, formerly an engineer at Schlumberger and technical director of an MIT venture fund, The Engine.

In this episode of "Energy Switch," what's new in geothermal.

We always try to start with kind of a why the heck it matters.

You know, why should we even care?

Why should our viewers care about geothermal energy these days?

- The opportunities from geothermal, from the heating and cooling space all the way to the power side, are really tremendous to help us get to a decarbonized society.

- Yeah.

- I always like to say there's no fuels, there's no waste, it's local, what's not to like?

It can power industry, it can provide heat, and can provide electricity.

You name it, it has it all.

[laughing] - Well, we're gonna get into all that stuff.

You know, let's just start real high level.

Geothermal is this term and what does it really mean?

- It really means the temperature from the Earth.

Now, there's many ways to break it down, but one of the ways I like to use is by resource type.

So we start with the shallowest, being ground source heat pumps.

- So we're 10 feet down here or something?

- Yeah, 10 feet down.

No more than 100 feet down.

- Okay, and the heat there is what?

What are we looking at temperature-wise?

- It's about 55 degrees Fahrenheit.

Constant, regardless of where.

- Steady on.

- Yeah, it's pretty stable.

That's very useful for residential heating applications and district heating applications.

Heating houses, heating schools, heating buildings.

- The shallow stuff, heating residential district.

Then what?

- So as you move higher in that temperature continuum, there's an opportunity for power production.

For power production, we're usually talking on the, you know, above 175 C. So, you know, above 300 or so Fahrenheit.

So basically a geothermal field, a hydrothermal field, where we're trying to access that hot fluid in the subsurface is comprised of many different well bores.

And a well bore is basically, just picture a big drinking straw in the subsurface made of steel surrounded by cement to kind of protect the rock.

And then, they would be connected to these pipelines that are transporting that heated fluid, which is basically our carrier, into a power plant.

- So geothermal, I've got my shallow stuff, 55 degrees, always nice there.

- Constant temperature.

- Can be to 100 feet down.

Hydrothermal, drill for it, but hot.

- Yep.

- Comes to the surface.

But natural, we call that natural, hydrothermal and natural.

- Naturally occurring.

[Scott] We don't have to do anything.

- That's right.

- It comes out of the rocks.

- And then, we have enhanced geothermal systems and advanced geothermal systems.

In hydrothermal, you have three ingredients.

You have the heat, you have water in place, and you have permeability.

- Meaning the water can move through the rocks.

- The water can move through the rocks, warm up, and if you drill a hole, it comes out.

The enhanced geothermal system, we put the water in because nature doesn't have these two things in place.

It just has the heat.

- Okay.

- So hydrothermal reservoirs are very good wherever they occur, like Iceland, for example, or the Western United States, but they occur in very few places.

Enhanced geothermal systems, on the other hand, we can make anywhere we want.

- Okay, so you're still going down to similar depths, but they don't have the ability for the water to flow, permeability.

- That's right.

- Or they don't have the water.

- They don't have the water, so they don't have permeability.

- You have to do one or both to get it.

- That's right.

And advanced geothermal system is a different take on how you extract the heat down from the rock.

- Okay.

- They're all universally the same in the fact that you are moving heat from the ground into the surface for your purposes.

- For productive purposes.

- For productive purposes.

For heating yourself, for making electricity, for moving industry, they're all the same.

It's just a matter of the geological setting that you operate in and the opportunities you have to exploit something that naturally exists or something that you have to make manmade.

- Gotcha, so in my home, I don't need 300 degrees unless I'm trying to cook everybody in it, or the chicken in the oven, I just need 55, that's great.

I need the 300 for power gen, that gradient.

- For power generation, yep.

- And it's natural or hydrothermal in some places and other places I've gotta do things to it, enhance it or even advance geothermal to get it out.

- That's right.

One of the things that I would also add is there's an extreme version of the enhanced geothermal systems, and we call those superhot rock systems.

We're basically going deeper and hotter to get a lot more energy from the ground, and therefore improve the economics and move industry at large.

- Okay.

- When we say super hot, we're talking like 700 to over 1,000 degrees, right?

[Carlos] Fahrenheit.

- This is extremely high temperature, extremely high pressure environments.

So it's really exciting to be able to access those environments and to be able to- - It's the temperature and pressure environment consistent with a fossil fuel boiler.

- Or the surface of Venus, right?

- The surface of Venus.

- It's like pretty hot.

- Geothermal will never be as hot as to produce steel, but they will take a lot of electricity once we decarbonize or industry chemical manufacturing, and power plants burning coal, they are on the right temperature range for geothermal when you go hot and deep.

- How do you keep that kind of heat hot so that you can actually make power?

- Rock's an insulator.

To a great extent, the rock in the well bore as it makes its trip up, it's insulating it and preventing it from losing a lot of heat.

- Okay.

- And the trip is very quick, you know, even in very deep settings, you're talking about minutes.

If you wanna do better than that, you insulate casings, you insulate the pipe, and it helps it even more.

- Right, so that's kind of a trade off between efficiency and- - And cost.

- Cost, yeah, interesting.

So I've heard geothermal everywhere or something like that, but is it really everywhere or... - The resource is truly everywhere, so it's not a resource uncertainty, like there is with oil and gas, there's always heat, but the technological gap prevents us from getting to it.

I live in Boston.

If we're in Boston, you would have to drill down 10, 12 kilometers, that's about six to seven miles.

That's quite deep.

- That's a big hole.

- We could do it, with existing technologies, it's just too expensive.

So technological gaps are the one caveat in unlocking this resource for everybody.

- Just to add on to what you said, I would say that on the power side, there are these technology gaps that are keeping us from advancing and from utilizing that stranded heat that's in the subsurface.

But on the heating and cooling side, there are fewer technology gaps.

In fact, it's mostly about optimization and about cost.

- You mentioned kind of the gradients of heat.

Let's start on the low end with geothermal heat pumps.

What is that?

- A geothermal heat pump is basically a technology that takes heat from one place and it brings it to another.

So we're just circulating fluid through the piping that you see in the subsurface, and then there's a heat exchanger inside your house, which is a difference from how other heating and cooling works where we're actually exchanging that heat.

- And this can happen not just in homes, but more complex buildings and things as well, right?

- Yeah, they can do it at all sizes from single-family homes, to full schools, to full residential complexes.

As long as you have the infrastructure, right, because you need to be able to move this heat in and out of the ground, and that has to be planned for before you build this infrastructure.

- Right, and how expensive is this compared to traditional heating or cooling?

- The total cost of ownership is a lot lower when you consider the full lifetime of the asset.

In other words, it's very expensive upfront, but over a few years, five, 10 years, your electricity bills half or go down by 75%, and then they'll keep on giving for the next 30, 40, 50 years.

- Are these common?

A lot of people have these home geothermal heat systems?

- So more common are air source heat pumps, but geothermal heat pumps, there are two or so million of them in the U.S. right now and significant growth happening, because there are some places in the U.S. that are actually requiring any new builds look into and develop with a geothermal heat pump.

Because, you know, to your point, it's more expensive to retrofit.

Basically, in the picture, you dig up your yard, you dig up your driveway.

However, if you're building from scratch, it's really a no-brainer.

- So, you know, what are the benefits, I guess, for the home system kind of that level to the grid?

- I think the most clear benefits, it lowers electricity consumption significantly.

- Okay.

- They make the job of the heat pump easier by virtue of referencing the ground.

You still need to plug them into the wall and they still consume electricity.

They still have a compressor.

It's just that that machine is working at 25% of the level.

- Okay, good partnership.

[Carlos] Good partnership.

- Right.

- I can't state how dramatic the impacts of full-scale geothermal heat pump deployment would be on the grid.

The cost savings are on the order of billions of dollars, and then the emissions reductions are just as incredible.

you know, millions of tons of CO2.

- Right.

- So that's really an impact.

- With no new technology required.

- Are there subsidies in this IRA?

- There are, yes.

It's basically 30% credit to the cost of a geothermal heat pump.

- Really?

- Right, and then up to $2,000 in other costs.

- Air or?

- For geothermal specifically.

- Geothermal.

- It's a big win to see geothermal in the legislation, because we're not typically included, so that is a really significant cost reduction.

And there's also something very exciting from the policy standpoint, the Defense Production Act, so this is when we can say we need you to accelerate development of X because it's for the benefit of the nation.

Geothermal heat pump manufacturing was included in that and that's also a game changer.

So that helps incentivize and put money towards the development of the components of heat pumps to help get more out into the market quickly.

- Gotcha, interesting.

Let's kind of go up to the next heat level, if you will, the district heating, and how does this work?

- So it's essentially the same, but with more fluid flowing through the system, because now you're having to heat or cool bigger spaces, an entire building, a university campus, or entire blocks of cities.

- You have to go deeper for it?

Or is it still kind of the shallow?

- Well, it depends on the location, but normally you have to go a little bit deeper and you have to access more land, more space, because you're exchanging heat with more rock volume.

- Right.

- Right.

So you have to size it to the heat loads that you have up in the surface.

- What if my power goes off?

Do the pumps quit working and I'm in trouble?

- No, there usually is some backup.

I think that there's an example of actually Whisper Valley in Texas during one of the big power outages where they have a sort of district system and everyone was still, you know, operational heating and cooling-wise, yeah.

- Okay, backup is from- - It varies, usually electric or, in some cases, fossil if necessary.

- Yeah, diesel.

- You need to do that.

And it will depend, in some places the resource has the characteristics that you can actually exploit the thermosiphon effect, and that's something typical of geothermal.

It means that a column of cold water being heavier than a column of hot water will push into the ground and lift the hot water back up just like a geyser.

- Interesting.

Where do we see district heating more currently, and where is it growing?

- So in the United States, the most dramatic growth, I have to give it up for the universities.

Every month I hear of another university that's deploying, either retrofitting or they're building new systems for district heating.

So a number of universities in the northeast, Colorado Mesa University, Ball State University, Amherst, all over the U.S. And then, the Department of Energy, where I work, we're funding a couple of exciting projects to develop district systems, but with deep wells.

So they're actually combining some ideas used in Europe where they're calling them deep direct-use at Cornell and at West Virginia University.

- Interesting.

- I think Europe is also a pioneer in this space.

If you look at Europe, they lean a lot on this district heating concept.

- Okay.

- And if I could add, we are working with a couple of military installations to look at feasibility studies, but there is such significant interest from DoD right now because of their, you know, ability to be able to be, you know, carbon free and also be sort of- - Energy secure.

- Energy secure, local basis.

- That is a big deal.

- It is really exciting to see.

- Easier, it's always there.

Would it be easier to grow these technologies from home all the way up through district than a power plant?

- It's hard to compare, you know, which is technically easier.

I think there are things that we have to take into account when we're retrofitting or building district systems, just incorporating, you know, where there might be existing infrastructure in the subsurface that you don't wanna accidentally interact with, all the wells, and the drilling of the wells would be regulated by the EPA, and so there's certainly things to consider.

But I think that there is known technology that is deployed all over the world.

The first deployment in the U.S. was in the 1800s in Boise, Idaho.

So we know how to do this, we can do it.

And I think it's just a matter of optimization to be the most efficient it can be, to incorporate other renewable technologies into how our district systems work, and then just a matter of-- [Scott] Right, so it's partnering systems in a lot of ways.

- Yes.

- It's also worth noting that geothermal is perhaps the only renewable that can provide heat.

Right, so wind and solar do not provide heat.

They can provide electricity, which can then be made into heat, but that's a very inefficient process.

Concentrated solar can provide heat, but that requires very high levels of solar radiation.

So geothermal really is very uniquely positioned to fill in the heat gap, clean heat gap that currently exists.

- Well, let's keep coming up in the kind of the thermal intensity now, power plants are a different challenge.

Where are geothermal power plants today?

And why are they there?

- So geothermal power plants in the United States are generally located in the Western U.S., and they're located there because of the geologic conditions.

- Like big plate boundaries?

- Yeah, the crust is thinner or we happen to have called the Ring of Fire, so around the Pacific Ocean where we have tectonic boundaries, there's just this ability for more heat to be closer to the surface.

And so, generally, when you see really prolific geothermal, natural geothermal systems, they're in Japan or they're in, you know, the western coast of South America, or in California and Nevada.

California and Nevada represent 90% of the U.S. geothermal resource.

So there is a dramatic- - For power plants?

- For power plants, yeah.

- Gotcha.

Where's the growth areas for these, Carlos, for power plants, and what does that technology look like?

- Yeah, so back in the '50s, '60s, the concept of binary power plants started to come about.

Let's say you produce geothermal water at less than boiling point.

You know, let's say 170 degrees Fahrenheit.

It's not quite hot enough to make steam, move a turbine, and make electricity like a normal power plant.

But you can use that heat and transfer it to another fluid that evaporates at a lower temperature, like an alcohol, and you make steam out of that secondary fluid, and that one moves the turbines.

- So that's the binary part.

- That's an organic Rankine binary cycle.

That's very well established technology.

As you start getting into things like the geysers, well, that resource is very hot.

It produces steam, dry steam, and you can actually feed that into a turbine.

The advantage there is that you will produce a lot more energy per well.

So the economics are radically better, because whatever money you invested in building the subsurface is going to be recovered faster by virtue of how much energy you're producing.

- Right, so we're talking about something with geothermal fields that are here for a long time.

I mean, you may have to manage it, but it's always on.

- It's always on.

- I can dispatch that electricity into a grid.

- Yes.

- And play well with intermittent sources, like solar and wind, or other things.

- Yes, this is very high value to the grid in the United States, and in states especially where we have that variability in other renewables.

- Going more globally, where do we see it developing in other places?

- There's massive growth happening in Africa.

Turkey is expanding on an incredible rate.

Indonesia is the second largest producer right behind us in the world and growing rapidly.

There are really high grade, very, very hot resources there that I'm sure are of interest.

And then, the Philippines, Italy, New Zealand on the list.

A lot of exciting growth in Europe as well.

But there is not necessarily a power production angle in Europe, they're looking at it just from the heat production standpoint.

- Okay.

- One piece I would add to that is just that the promise of the enhanced geothermal systems, and the advanced systems, and super hot is that you don't need to wait for an existing system to be developed or you can create it anywhere.

- Where is EGS working now?

Where are some of the best examples of enhanced geothermal today?

- France is the first one that comes to mind.

- Okay.

- There's a resource there that's been operating for decades, very reliably, very constantly.

And it's expected that it'll continue to do so for another 5,200 years.

[Scott] Okay, give me a feel for scale.

- It's very small, they're all scientific research type.

- Oh, they are?

- We're talking about a couple megawatt type electric.

- Okay.

- For a nation of gigawatts, that's very, very small.

- So there's no commercial scale enhanced geothermal today?

- Oh no, there is.

I mean, in France and Germany, they're using it not for power production in Germany, but more for heat production, because there the incentives are such that that made more sense.

And the Department of Energy funded a number of demonstration projects in enhanced geothermal systems over the last 10 years.

And they are what we call basically near field.

And what that means is that you're taking advantage of what's already existing in a geothermal, like a development, a hydrothermal development.

and we're moving to the margins of that area where we might not be able to find a well that has all those three characteristics, the heat, the fluid, and the fluid flow pathways to create this perfect natural system, and instead we go there and we add one of those things.

We've demonstrated successfully at the Geysers Field, which is the largest steam field in the U.S. in Northern California, just north of San Francisco, and in a field in Nevada that's called Desert Peak that you can produce power.

They're operationally running right now with basically those projects produced five to 10 megawatts additional.

- Okay, there's still government incentives on the table, but it could go independently commercial at some point.

- Well, technically there aren't really any federal government incentives where the Department of Energy is funding research in that space.

But there are folks developing without our money at this point.

- There is a public company, Ormat, you know, in the New York Stock Exchange, and it's gone public and private several times and it's been viable for decades.

So there are commercially viable companies and industries, because there's after all 15 gigawatts, or so, of geothermal electricity around the world.

But, again, I think- - But is it the enhanced kind or is it the hydro?

- It's mostly the hydrothermal kind.

- Okay.

- The enhanced, you count it, it's a handful, some with greater success than others.

It's emerging technology, there's a lot of research going on.

But people do the research because they see the potential.

- Yeah.

- To that point, there are a handful of these EGS, enhanced geothermal systems, companies that are now getting this headstart, because of, you know, the state incentive, for example.

- Yes.

- But once there's successful commercial deployment on the table, I think one of the things we haven't talked about is the fact that it's very challenging for geothermal developers to get financing.

And I think this is one of those nontechnical barriers to seeing more deployment, because there's an inherent uncertainty in our development.

We don't necessarily know exactly what's in the subsurface, right?

So we can estimate, we can collect data, ultimately, until we drill a deep well to see if there's the fluid, if there's the permeability, we know there's the heat, but how much heat is there?

And so it's challenging to sometimes get financing as a result of that.

And so the more demonstrations that we have that are successful in EGS, and I think that there'll be more private financing to follow that.

- Capital is scared of uncertainty.

- Yes.

- Yeah, but the same is true of oil and gas.

- Oh, absolutely.

- The same is true, right?

So how come the oil and gas is so prolific?

Well, because it got a head start of 100 years, and there's techniques, and methodologies, and portfolio approaches to diversify the risk.

I think geothermal doesn't quite have the skill to do that yet.

And I think they still need to calm down their cost curve significantly, right?

But I think the incentives to decarbonize the world create the right backdrop for things to happen, for these things to gain scale.

- Are there new technologies coming?

- There are new technologies.

So my company works specifically on something called millimeter wave drilling.

It's repurposing ideas from fusion research, very high power sources to vaporize rock.

So instead of- - Millimeter wave drilling.

- Millimeter wave drilling.

- To vaporize rock, we're talking lasers or what?

- We're talking about masers, the M stands for microwave as opposed to light.

[Scott] Okay.

- So the idea is that you don't have to replace drill bits and there's nothing that breaks.

So you still use a drill bit to get through the first portion to the basement rock.

- When you say basement, you mean hard rock?

- Hard rock, it's granite or basalt.

and it's very, very hard, very hot, very difficult.

It wears drill bits very fast.

So we're going to use energy.

We use energy, we just, literally, we vaporize a hole through a rock.

- What's the source of the energy for the maser?

- Electricity.

It could be from the grid, it could be from diesel generators.

- Could be.

- It's like an oil and gas drilling operation in that you have to carry your power.

Now, one of the key questions I get is, "Well, but if you're burning all this diesel to make this hole, does it pay back?"

It does.

- Sure.

- We recover 10,000 times the energy that we invest.

And as the world decarbonizes, hopefully, that electricity is no longer coming from a diesel generator.

- Okay, we're lost in techo land here, geeking out.

You know, this is the kind of thing that are game changers.

- That's how the future gets created.

[Scott] Our guests agreed that advanced geothermal technology is exciting, but still experimental.

Mostly because deep drilling is cost prohibitive and current technology can't handle the high heat.

If new technology does become affordable, it could be a significant source of electricity and industrial heat.

Hydrothermal resources, intense heat near the surface and permeable water saturated rocks, can be tapped with shallow wells and the steam brought up to generate electricity, but there are only a few of these sites around the world.

Geothermal heat pumps, which circulate water through pipes buried in constant temperature soil near the surface, can supply most of a building's heating and AC, ease pressure on the grid, and reduce emissions.

The upfront cost is high, but over the life of the system, it becomes more affordable.

This form of geothermal is the most widely accessible and deployable in the near term.

♪ ♪ ♪ ♪ ♪ ♪ [Narrator] Funding for "Energy Switch" was provided in part by the University of Texas at Austin, leading research in energy and the environment for a better tomorrow.

What starts here changes the world.

And by EarthX, an international nonprofit working towards a more sustainable future.

See more at earthx.org.