SPEAKER_03: I'm Kara Miller.

SPEAKER_01: And I'm Rob Stoner.

SPEAKER_03: And from the MIT Energy Initiative, this is What If It Works, a podcast looking at the energy solutions for climate change. Today we're going to examine an energy source with huge potential to shape the future. But one that's not without some complications. Hydrogen. And let's start with a little story about hydrogen and how its power can kind of creep up on you. The story takes place in the late 1980s in Mali, in West Africa.

SPEAKER_00: Okay, so the Molly story is really an interesting one. This well that was being done to find water, and they got down to about 100 meters. They didn't find water, but they noticed that there was wind blowing out of the well.

SPEAKER_03: That's Brad Hager, a professor of Earth, Atmospheric, and Planetary Sciences at MIT. He's also the associate director of the Earth Resources Lab.

SPEAKER_00: So, as usual, they uh sat down for a break to ponder the situation, and the crew member lit up a cigarette, and kaboom, uh, this uh big blue flame shoots out. He was burned. Fortunately, he he recovered. And it continued to burn in this bright blue flame for several weeks. So they had to figure out how to cap the well. And you know, capping wells is is uh a little bit tricky, and especially in Mali, they didn't have the expertise to do it, but it burned for several weeks and finally they capped it.

SPEAKER_03: So, what was the importance of this big blue flame? Well, no one explored it for a while, Hager says. The well just sat there for 15 years.

SPEAKER_00: And a local entrepreneur decided that he would invest in a lot of parts of the Mali economy, and he he uh invested in a uh wildcat oil and gas company. And so they decided they'd find out what was in the well. They took a sample and they found out it was 98% pure hydrogen.

SPEAKER_03: Now, this was a pretty amazing find. But Hager says there just wasn't the infrastructure to transport the hydrogen.

SPEAKER_00: The only thing they could figure out to do with it was to run a generator, so they got an old Ford uh motor and hooked it up to a generator. They now produce electricity uh for the local village because they can't go anywhere. You know, this is very exciting. The equivalent amount of energy that's produced in this well is uh about three barrels of oil equivalent each day, which is about 120 gallons of of gasoline. So you can think 120 gallons a day, you can run a pretty big generator for a village, but but that's about all you can do. Plus, Molly is politically unstable. There have been three coups since 2012 when they did this, so no big company is going to go in there and try to produce this.

SPEAKER_03: But the find points to hydrogen is a clean energy source of the future. So let's say we could get a lot more hydrogen out of the ground. How would that change things?

SPEAKER_00: It would be huge. So right now we are producing about a hundred million tons of hydrogen annually to use primarily for fertilizer manufacture. So you want to make ammonium, you want to feed the world, you use fertilizer made substantially out of hydrogen. But going into the future, using hydrogen to make steel, for example, instead of using coke, would take away a tremendous amount of the CO2.

SPEAKER_03: But here's the catch. You don't find such concentrated sources of hydrogen in very many places.

SPEAKER_00: So we do now understand why it's there in Molly. And it's a very special circumstance. There is a uh a trap, very much like the traps that hold natural gas accumulations. And in this case, the the trap is made out of a layer of uh solidified magma. Underneath that magma, there is a layer of limestone that has a lot of pore space in it, and then deep in the earth, maybe one or two kilometers below that, there are some very old rocks, over a billion years old, that are full of uh iron. And there is a small amount of water that percolates through this iron-rich rock, and there's a chemical reaction that goes on that converts some of the minerals in this rock to a kind of rock called serpentinite, which is the same as asbestos.

In doing that, it takes the water and strips off the oxygen and uses that to essentially rust the iron that's in the rock and leaves behind the hydrogen. So over some period of time, we don't know how long, that hydrogen has been moving up towards the surface and accumulating in this uh reservoir below this cap rock.

SPEAKER_01: Brad, there's a lot of iron down there on the Earth's crust and a lot of water that circulates beneath it as well. Uh that would imply that if this reaction is going on between those two things, there's an awful lot of hydrogen potentially available to us.

SPEAKER_00: Yeah, that uh that sounds great. But uh, so first of all, uh the iron-rich rocks.

SPEAKER_04: That sounds great. But okay, now the other shoe's going to drop. Go right ahead.

SPEAKER_00: Okay, so first above all, the iron-rich rocks uh are not that common in the Earth's crust. Most of it we think about, you know, silica and and and other rocks, but in the crust, there's not much iron. Underneath Mali, there is a formation which is over a billion years old called a greenstone belt. It's a place where two continents smashed together and left the kind of a scar that's full of iron-rich rocks. The place where there are really a lot of iron-rich rocks that are coming up near the Earth's surface are at the extending plate boundaries at mid-ocean ridges. In terms of water, we have a lot of water at the surface, but at great depth, although there's often water, it's not often circulating very much.

And so, in order to run this reaction, we need a continuous supply of water. So, what's special about Molly is that they're right at the same place uh where there's this greenstone belt, there are also some old fractures that apparently are open a little bit and there's water circulating through it. So there's a local source uh in Molly, but we don't know how much is being produced there. Uh all we know is that it's at least some of it is being trapped by this cap rock.

SPEAKER_03: So let me compare this to oil, which you know people kind of have a sense of I think didn't you say it's like three barrels of oil a day coming up, right? So if hydrogen is an excellent energy source, is like sort of one of the things that's gonna happen or maybe already happened that people are gonna look around just sort of they like they realize that there was stuff in Texas, but there's also oil in the Dakotas, but there's also oil in the Permian Basin. Are they gonna look around and be like, well, so where's the hydrogen? Like, you know, can we go to Kansas and find it?

SPEAKER_00: So that's the process that's just beginning. And it's very much like oil was in the 1800s. People are beginning to look around, and there's a lot of effort in doing this. The United States Geological Survey has a big program to try to identify hydrogen systems that are comparable to petroleum systems. So what you need is you need some source rock. In this case, it's uh water percolating through iron-rich rocks. You need some cap rock. In Mali, it's basalt, most places it's shale, and you need a reservoir rock where the hydrogen will accumulate. So, right now, what people are doing is uh focusing on where these potential source rocks might be.

So, for example, in the United States, there's an old continental rift scar extending from Nebraska, Kansas, Iowa, Minnesota, Michigan. There's a structure called the mid-continental rift, and people right now are targeting that to see if they can find uh hydrogen there.

SPEAKER_03: So are you saying like that in, you know, like the upper Midwest, we're looking potentially at the kind of, I guess, not gold rush exactly, but I mean there have been times where people got really excited about different sorts of energy all around the country and obviously the world. Is is that gonna happen? And people are gonna like go there and be like, we can get hydrogen out of the ground. It's it's clean, it's a great source of energy. See if we can make a bunch of money here.

SPEAKER_00: That's exactly what people are doing. And uh both because they want to make a lot of money and because they want to save the world. So there is a huge amount of interest right now in the venture capital community. There's a guy named Bill Gates, who you might have heard of, who has dumped a substantial amount of money in in into a startup company called Breakthrough Energy, which is uh going big into uh into hydrogen. And just to quote Gates, uh, it could be gigantic or it could be a bust. But if it's really there, wow.

SPEAKER_01: Aaron Ross Powell Well, also we're hearing the people are estimating the cost if they're going to produce it like they produce natural gas by drilling into a deposit and sort of extracting it. And I'm hearing numbers like less than a dollar a kilogram.

SPEAKER_00: Aaron Powell Yeah, that's right. So people are anticipating even 50 cents a kilogram uh for these preexisting hydrogen uh deposits. And I think that's an order of magnitude less than what it costs to uh produce it by hydrolysis. Trevor Burrus, Jr.

SPEAKER_01: So that's wild, though. I mean, it's what a situation. Here we are trying to make hydrogen through all these complicated, energy-intensive means, and it might be beneath our feet at a cost we'll probably never achieve or may never achieve with these other techniques.

SPEAKER_00: Trevor Burrus, Jr. That's right. It's uh it might be really cheap and would be a big help in the uh energy transition. So there are a lot of uh, as I said, venture capital companies going after this. There are some startups. There's one right up the street here in Somerville, a startup called Eden Geopower. It was founded by two graduates of our department. But the notable thing is that there are no major hydrocarbon companies investing in this. They are all sitting on the sidelines with a wait and see attitude. And what they're worried about is that yes, there'll be some anecdotal fines, but there won't be enough there to justify the costs of the infrastructure to produce it and to uh really make a big impact.

So it they're playing wait and see.

SPEAKER_03: Aaron Powell That's very interesting that that you've got the big play. I mean, obviously, like Bill Gates is plenty rich enough to figure to saying, like, as you say, like it could be bigger, it could be nothing but whatever he's got the money to bet on it. But big companies would also have money to bet, but it sounds like no, they don't. Trevor Burrus, Jr.

SPEAKER_01: They have not only money, but they have data and and considerable knowledge about the ground. I mean, these companies have been drilling holes, some of them for a hundred years or more, and gathering all kinds of seismic data. Doesn't that give them a big advantage, Spread?

SPEAKER_00: Well, uh one would think with all these holes they're drilling in the ground, but uh the issue is they're drilling those holes to find oil and gas. And they're finding very little hydrogen in the holes that they've analyzed. So that points to a problem, and that is that it is difficult to accumulate hydrogen in the earth for two reasons. One, you alluded to it being a very small and slippery element, so it tends to uh escape. But the other thing is that microbes, I'll call them bugs, for my geophysical terminology, bugs love to eat methane. So the big methane seeps on the earth are at mid-ocean ridges where the plates are spreading apart and they're bringing hot rock up to the surface.

Those rocks are fractured, seawater is circulating through them, and there is a lot of hydrogen being produced. And if there are any of these microbes around, they will eat it pretty fast.

SPEAKER_03: Do people in, I mean, I think it's like Michigan and Minnesota and Iowa, under Lake Superior, where some of this stuff is, do people know that this gold, like that they are, you know, like Texas Part 2? Do they know this is happening?

SPEAKER_01: Sadly, something good's gonna happen in Michigan.

SPEAKER_00: Well, it was realized in 2012 that we could get hydrogen from the ground. In 2018, about these venture capital companies began to be put together and they began running around scooping up leases in places like Iowa and Kansas. Anyway, around two years ago, there was a great outpouring of publicity in um journals like Science and Nature talking about the potentials of hydrogen. So it's being picked up broadly in the press now, and everybody's excited about it.

SPEAKER_01: Aaron Powell So there's a gold rush going on, kinda. Getting going. And it's not just in the United States. I mean, I'm hearing about big discoveries in Eastern Europe, Africa for sure, maybe South America, Australia. Yep. It's all over the place. Is that what's going to happen? We're going to find this stuff and start producing it like natural gas?

SPEAKER_00: Aaron Powell Well, I think that we will find some of it. Australia is pretty far ahead, and you know, new finds keep coming up. Albania, the Pyrenees of Spain. I mean, there are there are a lot of these places. As you mentioned, Bill Gates has a lot of money. He can bet on this. I don't have enough money to bet, but I can bet my time.

SPEAKER_01: Uh but you say you have so little money that you have to bet. I have so little.

SPEAKER_00: Yes. I desperately want to uh make a contribution to saving the climate. Earth scientists uh have this saying we have multiple working hypotheses. Okay. And my working hypothesis is that in the very near future, we are going to run out of the hydrogen that is naturally accumulated, analogous to natural gas accumulations. Trevor Burrus, Jr.

SPEAKER_01: Because even if there's a high generation rate, it's it's leaking out at all. It's leaking out much faster than natural gas. Bugs are eating it. Trevor Burrus, Jr.

SPEAKER_00: Bugs are eating it, and groundwater flow in continental interiors is pretty slow. So I don't think we're going to be able to keep up using this analog of the kind of conventional natural gas system. So I think what we what would be the real breakthrough, and I think it's the breakthrough that we should bet on here at MIT, is answering the question: can we actively produce hydrogen in the same way that it's being actively produced at these mid-ocean ridge systems, where water is circulating through hot, iron-rich rocks and reacting in real time and at high rates with uh you know the water and the rocks are reacting.

Hydrogen is being generated, and it's coming up to the surface rapidly enough that there's more of it than the bugs can eat, and that it could be produced.

SPEAKER_03: So it's being produced in kind of real time. This is not like old deposits, right? Kind of like there's deep water drilling, like you're down there in the water, capturing it in real time.

SPEAKER_02: Yes, as it's being produced, kind of.

SPEAKER_00: Yeah, so not capturing it from the water, but actually going down into the rocks themselves and capturing it. Okay. This process actually is going on right now in Iceland. So in Iceland is on a plate boundary where the European and the North American plates are pulling apart, hot rocks are coming up to the surface. That's why we have these volcanic eruptions. And the rocks are all cracked up from the tectonics of stretching the crust. There's water circulating through there. Icelanders are using this hot water to produce geothermal heat. They've also been looking at the water and realized there's a fair amount of hydrogen in it, and they are actually extracting the hydrogen which is being actively produced at the mid-Atlantic Ridge.

SPEAKER_01: So you mean you're you're you're going to pipe away the water, so to speak?

SPEAKER_00: So the water comes up, they separate out the hydrogen, and then they're like soda pop. Like it's like soda pop. They just, you know, it and it's it's also got some carbon dioxide in it, but they separate it out, separate out the hydrogen. And then there it is, it's it's collected.

SPEAKER_02: So if you got hydrogen and iceland, what are you going to do with it?

SPEAKER_00: Well, they have a very clever solution. Iceland is where a huge amount of bauxite is smelted into aluminum because they have cheap electricity there. And what they discovered is that they can let the hydrogen be absorbed in the aluminum ingots. And if you heat the ingots, the hydrogen comes out. So they have a perfect serendipity where they've got uh heat, hydrogen, aluminum, and uh a transportation mode. So it all works together.

SPEAKER_01: It's like many other things, works for Iceland, might not work elsewhere. But so moving it around is a problem, though. I mean, if you if you gather it up, I was saying earlier, I mean, it doesn't, it's not a liquid at room temperature or anywhere close to it. You have to compress it enormously in order to get enough energy into a volume that's transportable. Can we move it around, or does that create a huge problem?

SPEAKER_00: Uh as you know, it it's it's expensive to move around. It is being moved around right now, uh primarily in the form of fertilizer, the uh ammonia. The optimal thing would be to uh produce fertilizer locally.

SPEAKER_03: Aaron Powell So you you pull it out of the ground and then you think, what did we want to use this thing for? Let's have a plant right here that makes fertilizer so that we don't like lose half of it in transport or this or that.

SPEAKER_01: It's just another thing that works great in Iceland, too, because they could generate electricity from geothermal and use you know the Haberbosch process to convert it into ammonia and chip ammonia instead of aluminum, or maybe along with the people.

SPEAKER_00: They could do that, yeah.

SPEAKER_01: You know, Brad, I as you know, I think a lot about developing countries, countries that are economically poor, but in many cases also, and perhaps this is why they're economically poor, also resource poor. The possibility that they have these hydrogen-producing rocks right on their doorsteps, right beneath them, is exciting to me. What about places, for example, in Southeast Asia and in Africa? Is is what's the resource opportunity there?

SPEAKER_00: Yeah, that um that's great. And it's something I've I've thought a lot about. So let's start with Southeast Asia. India has a very large deposit of flood basalts. When the dinosaurs were killed 65 million years ago, at the same time, there was a huge volcanic eruption going on uh over the continent of India, and many people thought that that's what killed the dinosaurs. Anyway, so there's all this 65 million-year-old iron-rich solidified lava overlying a large portion of India called the Deccan Traps. And that is full of iron. Uh, basalt. It's basalt, yeah. And it's uh a lot of it is right next to the ocean.

So that there's a ready source of uh water nearby. So that's you know, potential that uh you know I would imagine could be low-hanging fruit for the Indians. And then also in India, when India smacked against Asia to form the Tibetan Plateau and the uh Himalayan mountains, it trapped some very iron-rich rocks in between India and Tibet. So that's another potential source of very iron-rich rocks that the Indians might be able to tap.

SPEAKER_01: What about the rest of Africa? I mean, it's ancient rock, cratons, I think they're called. Yeah.

SPEAKER_00: So Mali is in one of these ancient cratons where these uh iron-rich rocks are called greenstone belts uh from you know some of the fossil plate boundaries back billions of years ago. And also in East Africa, you have the East African Rift, where you know the crust is pulling apart, bringing iron-rich rocks uh you know closer to the surface. There are volcanoes erupting there, so that would be another potential uh you know area where you might find hydrogen.

SPEAKER_03: It sounds like you feel like the venture capitalists maybe they won't make the kind of money they think they're gonna make, or is that wrong?

SPEAKER_00: I don't know if they'll make the kind of money that they think that they will make. Uh uh there may well be return on investment for the first wave of venture capitalists. Okay. But whether this is something which is going to sustain us till 2080, for example.

SPEAKER_03: Right. Will they quickly run through?

SPEAKER_00: Well they run through and and you know, they'll make a killing on their initial investment, but is it sustainable? Is it scalable?

SPEAKER_03: And then another question is when you talk about this, the thing I think of is like fracking. Yeah. Um not very far from the kinds of places that you're talking about. A lot of people who live around fracking sites would tell you it's not so great, and there have been a lot of problems. So are a whole new set of people about to come in for the same kinds of problems that the people near the fracking sites have?

SPEAKER_00: Right. So that's a very good question. And I think that's one of the potential obstacles for actively producing hydrogen. I want to be clear, it's not going to be a problem in Kansas where they're just drilling in the same way that we would for natural gas. But if you move to, say, Southern California, there's a uh a spreading uh plate boundary that comes right up into the salt and trough area of of Southern California. There's geothermal produced there. In many ways, it's an analog to Iceland. It could well be a place where we would produce hydrogen and use it to make fertilizer, etc. Uh, you know, I think you're you're going to run into people who are very worried about some of the same problems that uh that fracking produces.

Because in order to reach these hot rocks, most places you're going to have to uh drill down and fracture the rocks to establish permeability.

SPEAKER_03: Are you worried? And and what do you think could happen to like ordinary people?

SPEAKER_00: Right. So there are a lot of issues uh with fracking. One of the main issues of fracking is that a large amount of water has to be injected into the ground. And then once the pumping starts, the fractures close and the water comes out. Uh the surface of this dirty water has to be disposed of, and that that's a problem. Okay. Uh stimulation of hydrogen, uh, that is not likely to be an issue because actually what happens is quite a bit of water is absorbed by the rocks in the process of getting uh of forming the hydrogen. And so you put the water down and it does not come back out. So that's one advantage that it's got over uh fracking for natural gas.

You're going to have to have an infrastructure to do that. That infrastructure can be messy, and there will be environmental effects associated with it. Probably the major environmental effect is that when you inject water into rock and Change the composition of the rock, the rock that's down there expands by a substantial fraction. It expands by about 30%. So if you're have a zone of rock that you're producing at a depth of a kilometer, it's going to cause uplift at the surface. If you're tilting the uh aqueduct and irrigation ditches in Southern California, people are not going to appreciate that.

So you're going to have to be very careful to do this in areas where you're not affecting uh infrastructure.

SPEAKER_01: Aaron Powell What about water consumption itself? I mean, if we're producing something like, well, let's see, today's total consumption of hydrogen is something like 100 megatons globally. Right. If we really go big time and find other applications for it, maybe we have a gigaton of hydrogen. Well, okay, so you think about H2O. O has a mass of 16, hydrogen's got two, so that's eight times as much mass of water. So eight gigatons of water. That's a lot of water. Or how is that not a problem if we're producing in the interior of a continent, for example?

SPEAKER_00: Yeah, so so the uh the problem is actually worse than that uh because your your uh your rock to hydrogen ratio is not one to one, but it's more like 70 to 1. So you have to react an awful lot of rock and an awful lot of water to produce some some hydrogen.

SPEAKER_03: So this is being like injected.

SPEAKER_00: So you're injecting huge amounts of water. So it sounds like an awful lot of water in an area you know like like superior Lake Michigan, where you have all these rivers flowing into it, it would not be a problem. It would be a problem in in Nevada, for example, you know, if that if that were there.

SPEAKER_01: So it so a ton of water is just a cubic meter. So we're talking about 80 billion cubic meters of water a year, which is a tiny.

SPEAKER_00: 80 billion sounds like a lot too, but when you figure out how you'll have to be a little bit of a big thing. That's a tiny, tiny fraction of Lake Ontario. It's uh it's it's it's not that much water. But one great thing about this is it does not require particularly clean water. So you don't have to use potable water to do it. You could use water from the sea, you could use water from uh saline aquifers, so you can use cruddy water to do it.

SPEAKER_03: So at what point are we going to be drawing a lot of hydrogen off out of the ground and it's really gonna be changing the game in terms of like our energy consumption?

SPEAKER_01: Yeah, you used the word will a second ago.

SPEAKER_03: That's interesting.

SPEAKER_00: Well, maybe I should have used wood, but uh um yeah, so I'm I'm I'm optimistic about this. So right now there are people who are trying to do this kind of stimulation in Oman. Okay, so Oman is a country in the Middle East, it's right at the uh the mouth of the Persian Gulf where all the oil tankers have to go in and out. And they have a very special geology there. Uh it was an old plate boundary where some iron-rich rocks got thrust up to the surface of the earth and they're actually exposed. And you can go and look at the outcrops, and you can see this transformation of iron-rich rocks into serpentinite, and you can see that happening, you know, in the in the outcrop.

And there are actually projects which are beginning right now. If those work out, I think that one could begin producing hydrogen in a place like Oman within the next, you know, certainly within the next decade.

SPEAKER_03: And once a lot of hydrogen starts coming out, are people going to immediately know what to do with it? Or are they then gonna have that secondary problem of thinking, well, we don't really have a fertilizer plant right next door and we don't really know how to transport this. So Yeah.

SPEAKER_00: So that's that's already a problem that that that's being worked on in the Mideast. They realize the future of natural gas, you know, with the carbon uh footprint, may be limited. And they're already, you know, investing in things like you know, fertilizer plants, exporting hydrogen from the Mideast to Japan, for example, using using fertilizers. So people are aware, very much aware of that. And these companies are carrying out uh reasonable technoeconomic analyses to see how to do this. So yeah, they're not going into this blind.

SPEAKER_03: So it sounds like in terms of years, we're looking at very soon. It's wild, right?

SPEAKER_01: I mean like in five years, we could see a significant amount of hydrogen being produced.

SPEAKER_00: That's my hope. You know, once it happens, I think people will jump on and and you'll get the investments and the technology that you need to really then scale this up to the to the size that we need.

SPEAKER_01: You you mentioned the breakthrough energy is investing in some of these companies.

SPEAKER_02: The Bill Gates company.

SPEAKER_01: Yeah, well, Bill Gates and others who are putting money into a building.

SPEAKER_00: Yeah, and also philanthropists are going out. The Granton Foundation has invested in this local company up in uh in Somerville, which is Breaking Rocks.

SPEAKER_01: Yeah, in Oman. In Oman.

SPEAKER_00: Breaking Rocks in Oman.

SPEAKER_01: So this is kind of crazy that we've got these philanthropic organizations doing all of the exploration work. And Exxon and Chevron are sitting on the sidelines twiddling their thumbs. I mean, what do we have to do to get them off the sidelines? When does that change? How sure a bet does it have to be? You're willing to invest your meager savings.

SPEAKER_00: Yeah. So um I think the uh the oil companies, uh, although they don't want to redirect their research labs to do this, I I I'm more optimistic than you are, perhaps because I less know less about it than you do is in your role in the uh energy initiative. But I think the oil companies should be investing in the you know small projects it will take to actually demonstrate the feasibility of it. Trevor Burrus, Jr.

SPEAKER_01: So you don't feel like there's some sort of Herculean demonstration that has to be made for them to begin to believe that it's inertia.

SPEAKER_00: Trevor Burrus, Jr.: I mean, this has only been out for a few years. You know, it's one thing to have these venture capitalists running around, but if you get you know the uh the gravitas of a place like MIT saying we've got this group of a dozen faculty, they really think this is great. And I suppose that's the other thing, is that this is a very multidisciplinary problem, right? You've got to have geologists who know where the rocks are, you have people who understand mechanics, understand rock fracture, how to transport hydrogen through the brines up to the surface, that how to stimulate the reactions on the surfaces that are broken.

So it's my hope uh is that you know, by seeing a place like MIT invested in this, and you know, these serious scientists uh who have many problems they could work on saying, hey, this is this is the one, let's do it.

SPEAKER_01: Oil and gas companies are uh risk-averse in many ways. They're making large capital investments, they want them to pay off, but they're also very sensitive to the public's reaction to what they're doing. And we were talking about environmental concerns a minute ago. But if we're gonna really be producing hydrogen beneath the surface by pumping water down there and fracturing rocks and so on, what what sorts of risks do do they need to be mindful of? What what bad stuff could happen?

SPEAKER_00: Yeah, I think that that that's a good point, and that's something uh you know that we really need to take head on uh before we run into a situation like it happened with the uh fracking, methane, and so forth. So just starting in uh in analogy with that. So hydrogen, there will be a certain amount of leakage of hydrogen into the atmosphere. So okay. I mean, that's just unavoidable when you're when you're handling this gas. We've seen the problems that that happen with the methane emissions associated with natural gas. So people are right now looking at the implications of additional hydrogen in the atmosphere and what that will do as a greenhouse gas.

SPEAKER_02: What will it do? I mean, I don't hear people talk about hydrogen as a greenhouse gas, I don't think it's a new thing.

SPEAKER_00: But first of all, I'll say we have hydrogen leaking out all the time. Right. So it's already there. So the question is, you know, how much are we going to be leaking compared to the natural flux? But hydrogen by itself is not a greenhouse gas. But there are indirect effects, and I think you know, probably one uh significant effect, which is easy to understand, when we emit methane into the atmosphere, it decays with a half-life of about 10 years, and that's because it's reacting with uh you know oxygen-containing radicals in the atmosphere. And so if you put hydrogen there, it's going to compete with methane.

And so the methane will last longer in the atmosphere. It won't decay as fast. So another problem I mentioned previously was just the surface deformation. It's something that happens slowly, gently. You want to make sure your pipes are not altered by it, but it's it's it's not a showstopper, in in my opinion, as long as you avoid critical infrastructure. Trevor Burrus, Jr.

SPEAKER_01: Your pipes? What it's a what's a pipe? In in your meaning your house?

SPEAKER_00: Well, in in let's say uh if if you chilled with Boston, it would change greatly the uh flow uh of sewers into the sewage treatment plant. So that would be a bad idea.

SPEAKER_03: Well, and I mean you see in California these like amazing pictures of how the ground is shifted because the aquifers have been so depleted that people may have a field of rice that's seven feet lower than it was when their grandfather had that field. I mean, like really shockingly different, and you can see it in you know, sticks that stick out of the ground or comparisons of pictures from now and and 70 years ago or something.

SPEAKER_00: Yeah, there's an amazing picture that the United States Geological Survey puts out for the Great Valley of uh California where there's a telephone pole and they have ground level marked on the telephone pole, and it's down like 80 feet from where the whole telephone pole from where it is right now. So um That's just from pumping the aquifers. That's pumping the aquifers. Yeah, but but now we're gonna be going the other direction. We can jack them up.

SPEAKER_04: But you have to do it in the same places.

SPEAKER_00: We can jack a bus in Harvard so we don't have to worry about MIT being flooded by by rising.

SPEAKER_04: Oh my gosh, we've solved so many problems.

SPEAKER_00: We can solve a lot of problems by selective uplift around the edges of continents.

SPEAKER_04: Brooklyn, we can make Brooklyn a little higher. We can solve, yeah.

SPEAKER_01: I mean, are we gonna really be producing enough uplift to be noticeable if we do this?

SPEAKER_00: Oh, absolutely. Yeah, because the amount of rock that's consumed, you know, as I as I said, you know, you consume like 70 times as much rock as you produce hydrogen. And so, yes, you're you're creating a a lot of uplift.

SPEAKER_03: Probably we won't be doing this in like Brooklyn and Shanghai and stuff, but it seems like a good place to do it.

SPEAKER_00: Yeah, but under the Great Valley is, you know, is plausible. There are iron-rich rocks under the Great Valley.

SPEAKER_01: So, what reassuring words can you give us to prevent the legislatures of the United States from immediately going out and banning hydrogen production?

SPEAKER_00: You know, I think the most fertile place for large-scale long-term hydrogen production is just on the offshore. So when North America and Europe, Europe split apart, the crust got very thin, not very far offshore here. And so we could do this under the water. We know how to do subsurface under ocean. So that's probably where we're really the big hydrogen production uh.

SPEAKER_01: So near shore meaning we still have to build pipelines, but they're not long intercontinental sorts of things. We're just getting it to shore. How far offshore is that?

SPEAKER_00: Uh it's about 100 kilometers offshore.

SPEAKER_01: Okay, so it's like offshore wind almost.

SPEAKER_00: Yeah, a little bit further than offshore wind because it it's in the somewhat deeper water, but uh yeah, well, uh I think uh another real serious problem uh could be the uh seismicity that's triggered by all this fracturing of rock. Meaning earthquakes.

SPEAKER_01: You just go too far and it lets go.

SPEAKER_04: There's gonna be a huge amount of deformation.

SPEAKER_00: But I believe that that can be managed. And one of the most interesting things about this chemical reaction when you take these kind of hard, brittle rocks and react them with water, and you form uh rocks like asbestos, which are very kind of soft and squishy, these rocks do not deform in a brittle way. They tend to deform like uh silly putty, you know, very, very in a ductile way. So there's a place along the San Andreas Fault in California, which has almost no earthquakes, and the earthquakes it has is is very tiny. And it's a region, you know, one or two hundred kilometers long that breaks the San Andreas into a northern section where the San Francisco magnitude eight earthquake happened, and the southern section where magnitude eight earthquake happened near Los Angeles, and in between, the plates are just slipping beside each other, just you know, like they're greased.

And huge amounts of deformation, larger deformation than than we would see associated with uh production of hydrogen, just happening without seismicity because the ground is getting uh all changed and looks different. So the the plates are moving. You can you can go to Central California and you'll go to a curb that crosses the San Andreas Fault, put a paint stripe across the curb, come back in a year, and you can see that the curb has been offset. Wow. No earthquakes in that time, it's just slowly moving along, you know.

SPEAKER_01: So the big one might never come to Central California.

SPEAKER_00: It will never come to Central California. People are very confident that the big one will never come to Central California.

SPEAKER_01: So do you not worry then that this is potentially induced seismicity is going to be a break on the development of terrestrial hydrogen?

SPEAKER_00: I do worry about that. I uh because my reasons for believing that it will not be are theoretical and based on analogy to the San Andreas fault. And and I think you know it this needs to be demonstrated uh in the field. And that there again, that's where this project in Oman could be very uh very important because uh you know they'll actually be breaking rocks they are injecting, and and and so we'll be able to, if they uh monitor that adequately, we ought to get a much better understanding of the earthquake uh generation associated with this.

SPEAKER_03: So when you just think about like right now in terms of your own career, yeah, um, does this feel like a very exciting time? And does it feel like uh like a pivot point to you? I just wonder in terms of the like the you know the research you do and the work you follow.

SPEAKER_00: This is uh a pivotal point. As I mentioned before, this is really an interdisciplinary problem. And you know, that's something I can do. I can I I understand, you know, kind of the boundaries between geology and geophysics and fluid mechanics and stuff. So for me, it's this uh new like playpen, you know, that just came just at the right time for me that I can, you know, think I can uh you know maybe do one more thing before and and it could be important, you know. If I can if I can make a difference in uh you know the transition to a low-carbon economy, that would be very gratifying.

SPEAKER_03: Brad Hager is Professor of Earth, Atmospheric and Planetary Sciences at MIT. Brad, thanks for being here.

SPEAKER_00: Thanks. It's been a pleasure. Thanks, Brad.

SPEAKER_03: What if it works is a production of the MIT Energy Initiative. If you like the show, please leave us a review or invite a friend to listen. And remember to subscribe on Apple Podcasts, Spotify, or wherever you get your podcasts. You can find an archive of every episode, all of our show notes, and a lot more at energy.mit.edu slash podcasts. And you can learn more about the work of the Energy Initiative and the Energy Transition at energy.mit.edu. Our original podcast artwork is by Zeitler Design. Special thanks to all the people at Mighty and MIT who make this show possible. I'm Kara Miller. And I'm Rob Silmer.

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