 Good afternoon and welcome to today's energy seminar. It's my great pleasure to be introducing our speaker today, Professor Roland Horn, from the Energy Science and Engineering Department here. He was formerly in the, as you can tell from his shirt, just the Energy Resources Engineering Department. I'll come back to a little bit more of a tie-in to this seminar and him in one second. But apropos of his title, I noticed last week there was a big announcement of a expanded funding package to further develop current and future geothermal technologies with three big awardees, one of which is a Stanford-based startup that Professor Horn had a lot to do with. He said he's going to talk a little bit about that as he goes on. I could think of no one better than Professor Horn to talk about the past, present, and future of geothermal energy because he's been involved quite a long time. I learned, actually almost by accident about three years ago, he runs a huge geothermal conference here every two years, I think. Every year, that's a lot of work that brings in people from around the world. So he studied this subject, old technologies, current technologies, new technologies, and all over the world. The personal tie-in to this seminar is not only is he the acting director of the Precourt Institute, which puts on or helps us put on this seminar, but he is also the founding faculty director of this very seminar, which probably was before there was even a Precourt Institute for Energy, a scenarologist. So please join me in welcoming our speaker for today, Professor Roland Horn. Roland. All right, thank you, John. All right, thank you all for coming. So my topic today, as you've understood, is geothermal energy. But in particular, I'm going to focus on kind of a new form of geothermal energy called enhanced geothermal systems. And you may have heard of that, or if you haven't, you're about to. I'm going to talk all about it. And just as a couple of minutes of introduction, the whole basis of geothermal energy is to take advantage of the thermal energy which lies below our feet, geo as in earth, thermal as in heat, and to bring it to the surface and use it in one of two ways. The most common is to, I won't say the most common, but the most visible one is to use it for generation of electricity. And that's something which is done around the world and has been for many years. And the second is to use the heat directly, either by placing it through heat exchanges and circulating the heat through buildings for district heating or building heat, stuff like that. Or sometimes directly for industrial applications like agricultural, product drying, steam supply for pulp and paper mills, things like that. So we like geothermal energy. And the reason why is because it's one of the lowest carbon forms of energy which we currently have available. So focusing on the electricity side of things, geothermal is one of the three lowest carbon lifecycle emissions of any available to us, the three being wind, nuclear, and geothermal. They're all about the same. This is not daily emissions. This is life cycle emissions. So it takes into account, for example, the manufacture and distribution of all of those different sources. So geothermal is a good thing. I might also mention to geothermal has a somewhat unusual characteristic compared to other renewables in that it is not intermittent. It's basically base load. It runs 24-7. And therefore, it occupies a very important place in a protocol or portfolio of renewable sources. So worldwide, the geothermal electricity production has been expanding steadily for more than 40 years. And in total, in 2020, at least, about 16,000 megawatts. Now, if you're not thinking in megawatts in your daily life, the California electricity grid is about 40,000 megawatts, 40 gigawatts. So this is roughly half of the grid for California. That's worldwide. So that doesn't seem so impressive when you spread it around the world. And actually, that's probably true. Another thing you'll notice about that graph is although that it's expanding steadily upwards, it's doing so in a kind of a linear fashion. So geothermal energy continues to expand worldwide, but nothing like as radically as some of the other sources. And I'll come to that in just a minute. There are certain places in the world, however, where it's expanding much more rapidly than others. So these three countries that I've identified here over the last five years have expanded tremendously in their geothermal output for electricity. Indonesia, Turkey, and Kenya. Turkey is the most notable of these because 20 years ago, in 2005, Turkey had only 15 megawatts of geothermal power. Today it has 1,600 megawatts, which is 100 times more. So it's expanded very rapidly. And importantly also, too, although in some places geothermal is a modest fraction of the output, there are some places where it's a very large fraction of the output. So this is the national grid of various countries. You can see Kenya, which is one of the ones I pointed out to you a few minutes ago, actually is at the top of the list. Almost half of their electricity in the nation of Kenya is from geothermal sources. And that's a very important contribution to their economy. They don't have any oil and gas. They don't have any other indigenous sources of energy. They don't have much capital. And geothermal then provides a very important part of the daily life of the citizens of Kenya. And you can see a list of other countries going down there. My original country of New Zealand is 80% renewable energy. And 16.7% of it is geothermal. Most of the rest is hydro. California actually produces 6% of its electricity from geothermal sources. So that's about 1 20th. So if you look above your head, 1 in 20 of the light fittings over your head are lit by geothermal energy, I'd like to think it's this one right here. And more importantly than that, our neighbors in Nevada actually produce now, actually in 2022, they reach 10%. So Nevada has a very more modest kind of geothermal resource than we do in California. Their temperatures are a lot lower. And yet they have a much more fostering legislation. And momentum basically has built geothermal resources in the state of Nevada where they would otherwise be relatively unattractive. And if we look at the overall mix of how geothermal, that's over the course of a year. This is over the course of 25 years. What you can see is the place. Geothermal is this one down here at the bottom. Although it is that modest 6% fraction, what you can see is provided that base load power throughout most of the last 25 years. And as an actual fact, that's been the case for 40 years. Hydro is an important resource for the state of California. However, one of the characteristics of hydroelectric power in the state of California is that it's intermittent on a different scale than solar and wind. And you all understand that. Those of you who live here, because we have droughts every five years, and we run out of water in doing so. We also run out of hydroelectric power. So you can see, if you think back over the recent past, we had a long series of drought up until 2016. And it rained like crazy. And we had a lot of hydro. And now we're currently been in a downswing also, again, for hydro. So hydro is an intermittent source as well. It's a very useful renewable source in a portfolio of renewable sources. But it's not a guaranteed source, at least not for a 10-year timescale. Now, if we look at renewables in general, I wanted to come back to a point I made before about the rate of increase of geothermal production worldwide. This is not the world, but this is the United States. These are the three largest sources of renewable electricity that we have, hydro, wind, and solar. What you can see from this graph, which goes back 25 years also, hydro is kind of stuck. In a natural fact, in some ways, hydro has somewhat shrunk a little bit for various reasons. The yellow one is wind. And wind basically began this sort of very sharp upswing in 2010, up to the point where two years ago actually wind overtook hydro as the largest renewable source of electricity in the United States. And the red one down the bottom you can see is solar. It's also expanding very rapidly, started later basically because of the economics. If you look at it today, solar is actually now the fastest growing. And most importantly, if we look at the state of California, again, you see a similar picture with wind coming in 2010, solar coming in 2015. And now the principle, the largest source, is solar in the state of California. BTM, if you're not familiar with the term, is behind the meter, solar. Those are solar panels on people's roofs. And then the orange one is utility connected solar. Right here in red, here is geothermal. So although geothermal actually currently makes up 12% of the renewable energy in the state of California, what you can see from this graph, we go back 40 years, most of the renewable energy electricity generated in the state of California came from geothermal. Although today it's been overtaken by wind and solar. So you might ask why geothermal is great, it's carbon low, it's expanding worldwide. Why isn't geothermal expanding exponentially the way that solar and wind are? And the answer to that is straightforward. The resources that have been developed in the world so far have been the good ones. People grab the cheap and easy resources first and they found them in geologically advantageous places. And unfortunately, there are not all that many of those geologically advantageous places and the good ones have been grabbed first. And that's why we don't see that kind of rapid increase in geothermal in the conventional sense that we've enjoyed in solar and wind. So what we need to do is to be able to develop methodology, technology and business methods to develop geothermal resources in places that are not as geologically advantageous. And for that then I'm now going to talk about enhanced geothermal systems, which is my principal topic for the day. So we need three things for a geothermal system to be effective and operative. One of them is heat. There's no way you can get around that. A second one is water. Because water is the sort of the carrying fluid that brings the thermal energy to the surface. That's actually not too much of a problem because the earth is effectively saturated with water everywhere. All rocks in the subsurface have water more or less. But the third thing that you need is permeability. And not all rocks are permeable. Some of them are very tight. And it's difficult for the fluids to pass through them. So the basic idea of an enhanced geothermal system is to create permeability where none exists or where insufficient permeability exists. And that's done by a process of fracturing, which is something that we know how to do. The idea in an enhanced geothermal system is to drill wells into rock, which is hot, saturated with water, but more or less impermeable. And fracture from well to well to provide a path for that water to go through the hot rock, sweep out those kilojoules of thermal energy, and produce them in the production well. And that's what defines basically an enhanced geothermal system. This is an idea that was invented a very long time ago. 1975 were thereabouts. And in those days, it was known as hot, dry rock, a term that kind of fell out of fashion because there's really no such thing. All rocks are basically wet, and which is why the term was replaced by enhanced geothermal systems. People built the first enhanced geothermal system in the 1970s, late 1970s, in Los Alamos. Los Alamos National Lab was a place where the idea was invented, and they built one in a place called Fenton Hill, which is in central New Mexico, not far from Los Alamos National Lab itself. And it worked kind of, but not particularly well. And after Fenton Hill has been a succession of other projects all around the world, and they all kind of worked also, but again, not very well. So the feeling that people have about enhanced geothermal system since all the way back into the 70s is it always seems a bit like fusion, nuclear fusion. It's always 30 years into the future because that's how long we've been waiting. And that's why I titled my talk today, Are We There Yet? And the answer, basically, which I will now give you is actually yes. We've recently got there in enhanced geothermal systems, and I'm going to talk about how that happened. So I did mention to you that at the moment, we are producing quite effectively useful amounts of geothermal electricity in the Western states because of the fact that we're geologically advantageous. If you look at a map of the subsurface, you can see why that is on the so-called ring of fire, the tectonic boundary, which lies along the plate of the West Coast of the United States. We have a lot of recent volcanism that gives rise to decent temperatures, commercially accessible temperatures, and drillable depths from the surface in advantageous locations that are permeable. But if you look at the map as a whole, if you set aside the consideration of permeability, what you can see is most of the West and United States are accessible for geothermal systems if we can enhance to get the permeability. We don't have to go only to the places that have permeability. And if you look at the scale on the right, which goes from 25 to 250 degrees centigrade, the good stuff, the kind of resources that we exploit now in the state of California, are at temperatures of 250 degrees centigrade, or they were in their outset. The ones in Nevada, however, are exploitable at a 150 degrees centigrade. That's their routine application in the state of Nevada. So you draw the line at 150 degrees. What you can see then, that's the oranges and the reds are always down to the yellows. We actually have at least half of the area of the United States accessible with today's technology for electricity production, using organic range of cycle power plants, if we can produce permeability. So that's our target. So what is stopping us from doing that? So there's a number of things. First of all, the heat of the earth is distributed over a very large volume. And therefore, if we want to recover commercial amounts of electricity, we have to sweep the heat from huge volumes of rock. I'm talking about cubic kilometers of rock. And what that means is we gotta have access. We have got a permeable access over those cubic kilometers of rock. So we have to be able to create fractures or permeability in one way or another through large volumes of rock on a kilometer scale. It's not enough, however, just to make a fracture from one place to another because were we to do that, the water would just go from point to point. It would travel through maybe a sufficient length, but it would not have sufficient contact with volume. So we need multiple fractures. We need a network of fractures which actually goes out over the whole volume that we want to sweep. Another difficulty is that although we can make fractures, it's hard to get a lot of fluid through them. And one of the issues with geothermal energy production is compared, for example, with hydrocarbon production, oil and gas, the energy content of hot water is actually very modest. Hot water, 1,000 kilojoules per kilogram, steam, 2,300 kilojoules per kilogram. That compares to oil and gas which are like 40 or 50,000 kilojoules per kilogram in terms of combustion. We don't want that, however, the consequence is that we've got to produce 50 times as much fluid from a geothermal reservoir as we have to from an oil and gas reservoir. And we do do that routinely. But what it means is that for a geothermal well to be commercial and profitable, which they certainly can be, they have to produce a large amount of fluid. So the target flow rate for a geothermal well is of order 80 kilograms per second. And if we translate that into kind of oil and gas terms, that would be 50,000 barrels per day. And although there are a few oil wells in the planet that probably produce 50,000 barrels a day, there's only, I don't know, half a dozen of them, very few. Average oil producer in the United States produces about 20 barrels per day. Orders of magnitude less. And then the final problem is seismicity or induced seismicity. If we're going to fracture rock, we move things around in a subsurface that can give rise to earthquakes and people don't like earthquakes. And therefore that is the opportunity for the loss, not the opportunity, the risk, of the loss of social license if we're producing induced earthquakes that affect people's lives. So we need to overcome all of those issues. Let's come to talk first about, you know, achieving sufficient flow rate where our target is 80 kilograms per second. And this is a graph that comes from a report that originated from MIT in 2007. It was one that looked at the economics of enhanced geothermal systems. And it was quite a promising report. It actually had a lot of influence on the U.S. government who started putting significant money into EGS development around that time. And they chose 80 kilograms per second as the level of output from a well that would be necessary to achieve an electricity price of about five cents per kilowatt hour. Now, five cents per kilowatt hour, at least at that time, would be the cost, was about the cost of wind energy. And again, to put that in context, the average cost of electricity varies a lot from place to place, but nationwide, it's probably around eight cents a kilowatt hour, something like that. So if you don't make it cheap enough, nobody wants to buy it, right? They want something else instead. So 80 kilograms per second is our target. This is what a regular geothermal well looks like. This is not enhanced geothermal system. This is just a normal producer, just one from my collection. This particular well producing 70 kilograms per second. So it's certainly feasible for a geothermal well to produce at those kind of rates. However, the enhanced geothermal systems which have been built around the world, I mentioned there's been many of them, not so many, actually about a dozen probably in total by different government research projects have fallen rather short of that. They've gotten better over time, but let's see where they started. So this is one from an enhanced geothermal project in France. It's a European sponsored project in a place called Sorts. And this shows their output, this particular well during a long-term circulation test basically stabilized at about eight kilograms per second. So it's an order of magnitude less than is needed. This is another enhanced geothermal project in Japan in a place called Higiyori. A lot of graph lines on this graph. If you look at the pink one, that is the production rate, which again is about eight kilograms per second. Then they had one project in Australia. They did a little better about 20 years ago. They produced 20 kilograms per second and on a later, you know, their best shot on a good day, they eventually got up to 35 kilograms per second. So we're getting, you know, within a factor of two. And then finally there's a project here in Germany in a place called Landau, which ultimately was producing 70 kilograms per second. This was the first commercial enhanced geothermal project actually in the world. Somewhat arguably so, it actually isn't quite the kind of project that I described to you in that they only fractured one of the wells. So they had two wells. One which was in Granite, which was the target usually for enhanced geothermal systems. And the other one was in a sedimentary fill which was a half kilometer away, something like that, which had sufficient permeability by itself. So this is, if you like, sort of a half-enhanced geothermal system and a half-natural geothermal system like the ones we have in California. And this actually shows you the arrangement. There's been a number of enhanced geothermal projects in the Rheingraben region. It's on the border between France and Germany. Two of these projects are in France and the other three are in Germany. So you see Landau there and you also see Sorts, which is the one that I showed you first. And Landau is a combined heat and electricity project, produces three megawatts of electricity and also provides heat to a district heating system. Sorts, the one I showed you, is basically a government research project. They had a one megawatt, one and a half megawatt power plant on it that ran for a few years. Ensheim is in Germany, produced 4.8 megawatts. It was the second commercial EGS project in the world. And then Rittishofen, which is in France, doesn't produce any electricity at all. However, it provides hot water to a factory, which is actually about 10, 15 kilometers away to provide their industrial heat. So it provides a total of 24 megawatts thermal. Were that to have been used for electricity would have been down basically by a factor of 10 because of the efficiency of the plant. So that's sort of a two and a half megawatt size project. So this is Rittishofen. This is before they put it into production. This is Sorts, not currently in production. And you can see actually the reason why Sorts no longer produces, that you can see the church in the far distance. That's the little village of Sorts-Sulfuray and they complained because this power plant actually made a lot of noise. Actually doesn't make a lot of noise, but it's sort of an irritating, high-speed turbine kind of wine that caused the, I mean, this is a very rural part of France. They complained and eventually they shut it down. It wasn't anyway a commercial project. It was one, it was as I mentioned, a government research project. Okay, how about the US? So I mentioned Fendern Hill. This sort of goes backward in time. Fendern Hill was the first one that they produced in Los Alamos. It was a government research project that ran for almost 20 years, actually well into the 90s before it was shut down. And then there's been a series. Following the financial crisis of 2008, the US government put a lot of money, about $200 million into enhanced geothermal systems and sort of threw it out there into market, said, okay, somebody make this work. And there were quite a number of attempts that you see listed up here over that time. Most of them were not double well-enhanced geothermal systems the way that I've been describing to you. They were largely stimulation treatments on the outskirts of existing geothermal fields that weren't very permeable. They kind of revved up some of the producers of more or less a conventional type. However, the three that I've listed up at the top are genuine EGS systems that have been implemented over the last few years. Two of them by a company called Fervor that John mentioned, what I'll talk about in a minute, and the one in the middle at Forge, Utah, which is a Department of Energy research project, which I'm also going to talk about. Okay, so I want to just change gears slightly and talk about how Stanford plays in this picture. So this is the Stanford Geothermal Program, which John mentioned, been in existence now for just about 50 years. When geothermal began development in the state of California in the early 70s as a consequence of the oil shocks, a program was initiated, not by me, but people more senior to me, if you could believe it, in the 70s who initiated that program, which it now still exists. But I want to draw your attention to this guy in the middle, Jack Norbeck, who received his PhD in 2016 from the Stanford Geothermal Program. He graduated from Stanford and he was one of the co-founders of this company called Fervor Energy. And the other co-founder is Tim Ladimer, the guy on the right, who is also a Stanford graduate from the EIPA program, as well as the MBA from the Business Corps. So they left Stanford with the full intention of creating an enhanced geothermal company. In fact, they came to Stanford with that intention and they just in through Silicon Valley style just went ahead and did exactly that. So Fervor took a very different viewpoint from all of the other projects I've been talking about up until this point. All of those projects, like the cartoon I drew at the outset, were two vertical wells, or sometimes deviated wells, which were fractured one to another. And one of the difficulties, which was one of the items on my technological barrier list, was the fact that with sort of one fracture or a few fractures going from well to well, you just don't reach enough rock, getting that distribution of fluid over volumetric. Heat source is what's needed to get commercial quantities over a long period of time from an enhanced geothermal system. So Fervor took a different approach altogether than anybody ever did before. Tim Latimer, the CEO and co-founder of Fervor, had worked for five years or so in West Texas in the shale play, drilling horizontal wells and multi-stage fracturing. So he decided to get out of the oil business and go into geothermal business, but he didn't leave aside all of what he'd learned in that process. And his idea was to apply horizontal drilling with multi-stage fracturing to geothermal, which nobody actually had ever done before. Typical wells, like the ones I showed you at Sultz and Higiori and others, were open-hole completions, which is something which is common to do in geothermal because the rocks are very robust. They don't require casings to actually hold the wells open, at least below a certain point. But what, and that's uncommon in oil and gas. Oil and gas always case the well from bottom to top, and it's cemented throughout, and the fracture treatments are created through perforations, gun perforations through the casing. That's what Ferber did. First of all, they drilled horizontal wells, and then secondly, they cased them from top to bottom, and then they did multi-stage fracturing with gun perforations from the tip back to the heel. And they did that in 2022. 16 stages of fracturing, one well and 20 stages in the other. And they got them connected, and therefore they're basically able to flow from one well to the other over the entire length of the two horizontal wells. So that gives them the kind of connectivity and the volume to surface ratio that you need to get the amount of heat to produce for a long period of time. Typically 30 years is what we're looking for. And the place they did that was on the side of a geothermal field in northern Nevada called Blue Mountain. And Blue Mountain was something of a sad story in terms of production because they had, they developed the field. It looked kind of promising, but it didn't really pan out. They built a power plant, had insufficient steam to keep it running. So what Ferber did is they moved to the side of the field where it was hot but not permeable, and actually permeability as a whole was generally a problem at Blue Mountain. They did this kind of treatment and then they were able to provide additional hot water and steam into the existing power plant. And as you saw in the previous, oh, I went back too far, they actually were generating 67 kilograms per second, which is right up to where we want. And they were producing three and a half megawatts in the existing power plant, which was sold to Google and ultimately used in the Gigafactory just north of Reno. Okay, so this is very different just to show you a picture of what they intended. This is not what they actually did, but this is a model of what they had in mind. But they only had two wells in Blue Mountain, so the idea is to have a whole series of these injectors and producers sort of plotted out across the landscape with multi-stage fracturing between them and basically then fill space with these fractures and then get access to all of that volume of heat. So Blue Mountain was 2022 and what they did then, I should show you this, that's what the wells looked like. What they did next then was to move into a greenfield area. This is not on the side of any existing field at all, but they moved out into central Utah. And remarkably, since July of last year, they have drilled six horizontal wells in this project, which they call CAPE. And if you just contemplate that momentarily, nobody had ever drilled a horizontal geothermal well before. In the five years since 2015, that's eight years, there were 5,000 geothermal wells drilled across the planet, including those developments I showed you in Turkey and Indonesia and many other places. Nobody ever drilled horizontal wells because it's kind of expensive and risky to do that. They drilled not only the first horizontal well and geothermal, they drilled seven more after that, six of them in the last eight months. So that's a tremendously high rate of activity. Not the only four of them are shown here. What they did also rather cleverly, I mentioned a few minutes ago, FORGE, which is a government, a US Department of Energy. This is FORGE right here. FORGE drilled two wells, not horizontal, but actually highly deviated. They're deviated at 65 degrees. So Fervo actually kind of leased the land next door to FORGE and in doing so, they took advantage of what was, had been learned geologically in the FORGE project, which began about four years ago. If we look at it in cross-section, here is FORGE. You can see their two wells, actually they have several wells, but the two main ones are like this. These are the four wells that Fervo drilled and two others which are towards the screen. And then over here on the right, there's an existing conventional geothermal plant called Blundell. And it was developed in the 1980s by Phillips Petroleum and is operating today. I forget how big it is, 20, 30 megawatts, something like that. So you can see this big purple body is the granite. It's the basement rock, which underlies, a lot of what's to be found across the planet. And you can see these temperature contours rising up in the Blundell region. So they drilled over here in the 1980s where it was hotter close to the surface and they developed a conventional geothermal system which had actually very good permeability. Down here in the valley, however, the permeability was not so good. This is much more like a monolithic granite body which doesn't have much permeability at all. And in fact, it was chosen for that purpose by the Department of Energy for Forge. You can see this well 5832 was a test well that they drilled first. And it was chosen over four other locations by the Department of Energy because they were looking for a body of rock that had low permeability to basically test out whether it was feasible to make all of this work. So here's further, they drilled their four wells and then they're actually right now in the process of doing their fracturing from one well to another. Now, one of the things that we should also talk about in the context of why we don't have more geothermal than we do is the cost as well as the risk. So this is a subsurface resource exploitation and it's subject to geological uncertainty. That's true of anything that you take from the subservice, mining, oil and gas, everything. So it means that you have to pay money. If the bank is gonna lend you money on a rescue project, they're gonna charge you more than something which is more certain. So cost and capital is an issue for geothermal production. In addition to which you can't actually have any income from a geothermal project until everything is built. You have to drill the wells, you build the pipelines, you gotta buy the turbine, you gotta build a turbine house. All of that takes three, four, five years and all of that time you're just bleeding money. Whatever you borrowed, you're just paying interest on, you get nothing back. So upfront capital is a difficulty for geothermal projects. One of the things that holds them back. Half of the cost of a geothermal project typically is the wells themselves, drilling the wells to recover the fluid. And this graph shows the performance, the drilling performance of the wells that were pre-existing at Blue Mountain. And I mentioned to you, Blue Mountain was a, was a just conventional geothermal project that's been running for 10, 15 years or so. So you can see the depths here. They drilled to about 6,000 feet and they drilled a couple of dozen wells in that environment in order to get to those kind of depths in that field, which is not at all untypical in geothermal fields, took about 60 days. And actually 90 days is not unusual for geothermal well drilling. That would be astonishing in oil and gas. The shale oil wells in West Texas, they drill them in about five days to the same depth, same horizontal length. Why is it different? Because they're drilling in sedimentary rock, which is much softer. Geothermal wells are drilled in volcanic rocks. They're harder, harder rocks, much more challenging drilling environment. So this is what, this is what would be typical. You'll also notice things like this long horizontal section here. This bearing mind is depth, but it's also indicative of time. So they spent what, probably here two weeks at the same depth. That's also a kind of a common image that you see in geothermal drilling because they got stuck, but it has a problem. They had to, they had equipment in the hole that had to fish out. So all of that takes time. You can see here, this particular well, they drill down to this depth and had a problem. They had to back up and backfill the well and start over again. They had to do that twice. So these are the things that make geothermal wells expensive to drill. This is what Fervo did in the same field. The two wells that I talked about five, 10 minutes ago. Now first of all, they drilled, this is actually so-called measured depth. This is not the actual depth because the wells actually went horizontally about 2,000 feet, but this is from the point of view of the person pushing the drill down the hole, this is how much drill pipe they ran in. So you can see those first two wells that Fervo drilled. First of all, they had some problems there too, like everybody did, but more or less they did a rather more successful job than had been done previously in the same geology. And importantly, the second one, they did rather better than the first. So they were improving. They were the one in the brown, the lighter brown, first horizontal well ever drilled in geothermal. So they did remarkably, you know, pretty much almost as well as conventional vertical or deviated wells. Okay, then they moved to middle of Utah and went on to their Cape project. And as I mentioned, they drilled six more wells. And this was their experience in Utah. So what you can see here is the accumulation of experience moving along the learning curve and actually getting quicker and quicker. So they got down to 20 days in the last few wells they drilled in Utah, which if a few of you are nodding, smiling, it's astounding. You know, you see the experience that people had over the last 40 years for conventional geothermal drilling. These guys cut it by a factor of three and they're moving even towards the factor of four. It's absolutely astonishing. Forge, by the way, the DOE project also did something similar. They took from their first well to their second. They went down by a factor of two in drilling speed or drilling time. So there's a tremendous improvement, enhancement of geothermal drilling technology, largely associated with the borrowing of ideas from oil and gas fields. And I'll talk about that in a moment. So, you know, things that cost time in drilling and bear in mind, of course, time is money. The longer it takes to drill, the more the project is going to cost. Difficulties in geology. Well cave-ins and things like that. MPT stands for non-productive time. Time where you're on site doing something but you're not drilling ahead. What makes it easy, first of all, is a contiguous body of rock. As I mentioned, you're looking for sort of a body of granite which doesn't have a lot of fractures in it. And in their project outline, Fervo had anticipated that they would actually have an improvement in drilling rate, the blue curve there. The Department of Energy was looking for a target for research of drilling improvement of 35%. That's what this blue line represents. After the early two wells that project Blue Mountain, they actually changed to this dotted line. They did a lot better than they had anticipated. And this line at the bottom is their actual experience in the eight wells that I described. And there's quite a number of ways in which they did that. But one of them was the adopting of this kind of drill bit known as a PDC or polycrystalline diamond cutter bit which is widely used in oil and gas. And interestingly enough was originally developed for the Fendenhill project in 1975. Geothermal project but never used again in geothermal after that one project. But the use of polycrystalline diamond bits allows for much greater weight on bit than a rotary or tricone roller bit. And that allowed them to have much greater penetration rates and much longer bit runs without having to take the time to change out the bit. And they experimented with a lot of different kinds of bits as they figured out what worked for them in all of those wells. So this is one of my current PhD students, Muhammad Aljubran. He's one of his projects is look at the levelized cost of electricity from EGS. He's done some interesting work. This is a map of the levelized cost of electricity with conventional geothermal drilling practice as of 2022. And again, if you look at the scale, this is in dollars per megawatt hour. So 8 cents per kilowatt hour is just around here around the orange level. That's the national average. So that's all of this, everything which isn't green or blue basically on this map. And what you can see then, we've got attractive regions in the Western states. The Gulf Coast tends to be rather hot. That's a good place for geothermal as well. This is with 2022 drilling practice. This is where the drilling rates that I just showed you, it basically lights up more or less the whole country, almost the whole country into the yellows and oranges. And that is very promising. So in terms of all of those hurdles that I mentioned to you 15 minutes ago, basically they were able to tick all of these boxes. And in addition to that, basically cut the drilling price in half. All right, two minutes more. Let me talk about a slightly different topic, which also relates to what Fervor has done. You're all familiar with the duck curve. This is California's output of non-renewable power. So this is the non-intermittent source on a daily basis. How much power the grid has to supply in addition to solar and wind. So because we have now so much solar on the grid in California and more so from one year to the next, what you can see here on this particular day and what day it was, 2023, the price actually goes negative. So there's more electricity on the grid than the grid can actually use. And the way that we now actually make use of that is with batteries. On a typical day where we're generating so much solar, the California grid can actually supply as much as 2000 megawatts out of lithium batteries or grid-connected batteries. So this whole issue of dispatchability and meeting this demand from one part of the day to the other is one of the challenges of the kind of modern grid that we have with a lot of intermittent power. Most importantly, you have this neck of the duck between 4 p.m. and 7 p.m. where the grid on this, which you can see here, has to supply as much as 15 or 16 gigawatts of electricity. It has to come online between three o'clock and seven o'clock in the evening. Geothermal, unfortunately, is not good at doing that. Geothermal is baseload that the plants don't like to be switched on or not. However, what Ferbo has been looking into is to use them in a different way, which is possible with an enhanced geothermal system in a way which was not possible in conventional one. And their idea was, since you have an injector and a producer, you keep injecting, but you stop producing. So during the middle of the day, running those injection pumps basically soaking up that solar, which is otherwise not really going to any good use. And then in the evening, this is an actual measurement that they did in Blue Mountain. You can see that stopping production for about eight hours, when they put the production well back on again, it produced at a higher rate than it was when they shut it off. So basically they're pumping up their reservoir and then blowing it off at 7 p.m. Getting the most valuable power out of it. And this is what it looks like over a series of days. They tried throwing back for a few days and in these days here, they actually cut back all the way to zero. So the net power is negative because they were actually consuming power off the grid to run the pumps. And then you can see it sort of came back stronger in the latter part of the day. And the advantage in doing that is that if you run the plant in that way, you can actually mitigate or avoid this particular part of a hypothetical grid would be this is combined cycle natural gas with CCS. This part of the graph, this sort of orange part disappears if you're actually using the geothermal source in a flexible way. And that avoids, first of all, it allows you to run the grid with a smaller total capacity and it also allows you to avoid the installation of lots of batteries, which are expensive. So then let me close at that point. Lots of exciting things happened in geothermal over the last 20 years, but EGS is probably the most exciting in terms of new ideas being put into practice and more importantly, put into practice in a commercial sense. So Fervor Energy is selling electricity to the grid and the CAPE project that they are now in the process of developing has already contracted for the generation of 400 megawatts. So we're no longer in the two, three megawatt range that people have been playing around so far. This is large scale operation. So with that, I will conclude and thank you very much. Thanks very much for a spell-dinding. You only have time for maybe one or two questions in the room if there are any. Let's go with these two here. Just they're ready to go. Go ahead. Yeah, I don't know what whole Fervor or why it's the new seismicity problem. Yeah, so the question is, how did they avoid the induced seismicity problem? The issue with induced seismicity, first of all, you never avoid seismicity. There's always something going on. The point is to have seismicity which isn't big enough to upset anybody. And what they did in both of their projects is they monitored the seismicity with geophones all around the plant. And then when the seismicity went to above a certain level, they were gonna cut back. A so-called traffic light system, green, yellow and red. So yellow means cut back on injection, red means cease it all together. As it happened, neither of the projects ever got out of the yellow. So they, and most of the time they were in green. So they were with seismic events set level two and below, which are not, you can't feel them. Human beings don't feel them. The geophones feel them, but the people don't. But had they gone up into the red, they would have stopped. Last question, John. Yes, real, why don't we get them on tour? So I was very curious in the talk, you mentioned one of the German projects had not only electricity production, but associated city or domestic thermal heat for heating or water. And I remember a number of years ago, somebody told me that in Paris, in France, in that geological structure, they were using geothermal heat, not for electricity production because the temperatures weren't right, but for domestic heating and hot water. How do you view the applicability of things like that because energy is going, of course, to heat water and heat buildings and stuff too. Where does this go for a lower thermal? Yes, the Paris Basin is a showcase for low temperature geothermal. They had more than 200 doublers where they're producing and injecting water that produce, as you say, they use in swimming pools and schools and apartment buildings and all those kind of things. And not just there, but in many other places as well. The nation of Iceland, 80% of the people have buildings that are heated by geothermal hot water, which the city of Reykjavik is a city, but there are people out in the countryside that get hot water reticulated to them in Iceland. And it's done in Turkey, it's done in China actually, it's the number one country for district heating systems in geothermal. Whole cities in China, like Tianjin, heated by geothermal sources. And you're right, it's a wonderfully inexpensive and reliable source of heat. Do you think the U.S. is really exploiting that, or is there a program that really exploits that? So, climate falls are again, most of the city is heated, schools and people houses have a little well in their backyard, Boise, Idaho, much the same way. And then geothermal ground source heat pumps widespread in the eastern United States, where it's colder throughout the coast, Atlantic coastal states. That's it, we're just about out of time, so let's thank Professor Wernmout for one last time.