As the world is moving towards diversification of the energy mix, geothermal energy shows great potential to play a crucial role as a sustainable and renewable source of energy. Mrigya Fogat, a content creator for The Way Ahead magazine had the opportunity to interview an expert in the field of geothermal energy, Andy Wood.
Wood is a subsurface manager at CeraPhi Energy, an advisory board member, and has 30-plus years of experience in the oil and gas industry, which he leverages today to develop advanced geothermal energy systems. CeraPhi Energy uses experience in the oil and gas industry to provide clean energy solutions to help the world reach net zero in carbon emissions.
Mrigya: We are really excited to have you here with us, to learn from your vast experience, knowledge, and passion.
Andy: Thank you very much for the invitation.
Mrigya: Thank you, Andy. So, to get right into it, I would like to start from the beginning. Could you please provide insights into the genesis of geothermal energy and the usage of it in mainstream energy requirements?
Andy: Sure. That's a big question. Geothermal has been around, of course, as long as the planet. If you look at earth, it has a core temperature of 6,000°C. It's very hot and that heat manifests itself in various places around the globe at surface. Talking about the genesis of the use of geothermal, ancient civilizations used it for direct heat. Wherever there was a hot aquifer that came to surface, then it would be used. The Romans were quite renowned, for example, for using geothermal energy whenever they could. But modern geothermal energy really began in Tuscany in 1994, where heat was actually converted to electricity for the first time. And through the 20th century, the geothermal energy business began to grow. It has developed through a two-well system whereby two wells were drilled: cold water was pumped into one well, and that water was heated by the earth and was harvested from the second well.
Well, now that this system is in existence today and is still a major part of the geothermal energy business, it does have its limitations. Those limitations have recently led to the evolution of the geothermal business and the open-loop system where those two wells are used has developed into, and necessitated, the invention of the closed-loop system, which relies only on the use of one well. The single-well solution is something that has recently, in the last 5 to 10 years, really caught the imagination of the energy business. And the reason for is that there are limitations, as I've mentioned, associated with the open-loop system.
Those limitations really are primarily the fact that you're relying on the subsurface to play ball if you would like it to do the things that you want it to do. There's a great deal of planning involved in the open-loop solutions, and they need subsurface—whether it is in a hydrothermal system where wells are tapped into, deep aquifers, or an advanced geothermal system where they drill into igneous rocks and rely on fractures and faults.
Both of those systems rely on subsurface communication between wells, and because geology doesn't always do what we'd like it to, then quite a lot of those projects fail. That of course, has been the big roadblock for energy. Nobody wants to invest in a project, which ultimately is going to give nothing back. So, the first problem with the open-loop solutions, is the lack of communication between wells. And then, there's another problem. The vast amount of water that's pumped into these wells sometimes generates earthquakes and that is also a problem in some locations. In some parts of the world, they experience earthquakes anyway, and it's not considered a big issue. However, to experience an earthquake in certain parts of Europe where geothermal energy projects have created earthquakes where they normally don't exist, has resulted in those projects being shut down. The other problems with the open-loop systems are the fact that they require vast amounts of water. And as you know, water is a very scarce resource and it's not something that we believe should be just pumped into the subsurface sometimes to disappear and never be seen again. The other drawback of the open-loop systems is that they sometimes bring a great deal of waste to the surface, which needs managing.
Now going to the solution, the closed loop. The closed-loop system, or advanced geothermal system, is only one well and not exposed to the subsurface. We don't have the problem of communication between wells; that's solved. We don't have the problem with secondary seismic activity because we are not injecting anything to the subsurface. And likewise, we're not using water because the well is a single closed loop. That means that we don't have to deal with waste either. So effectively, we've solved the age-old problems of geothermal energy.
Mrigya: That was very informative. I just have one question. In the closed-loop system, it is that you pump in water and that itself is retrieved from the same well?
Andy: Yes and no, because it is a closed loop, we pump a fluid, but it's not water. Because there's nothing entering or leaving the well other than heat, then we can choose whichever fluid we like to pump around this and this means, there are various companies using different fluid. But in the simplest form, it can be something like glycol, which has better heat-transfer properties than water. The company I work is looking into using all kinds of different fluids, as do some of our sister companies. We look into, for example, using butane and pentane, hydrocarbon gases, but also super-critical carbon dioxide because of the fact that they can transfer heat at different rates and different efficiencies.
Mrigya: So now that you spoke about some of the drawbacks and the challenges that you're mainly facing with development of geothermal, my next question is related to that. What are the major challenges in making the usage of geothermal, not just more technologically efficient, but also having a widespread usage of it throughout the world? And in these challenges, how can young professionals across different verticals of the energy industry, the tech industry, contribute?
Andy: Again, two big questions. I've already described some of the challenges. The open-loop systems and their lack of communication between wells, the secondary seismic activity, generated-waste management, and use of water. But I would go further than that and say the major challenge is awareness and hand-in-hand with that, reputation. I've just described quite a few major setbacks and those setbacks have led to companies being reticent about investing.
In geothermal projects, for example, if you spend $25 million on drilling a few wells with an expectation of receiving geothermal energy for decades and decades and then you find out that the project doesn't work because there's no communication between wells, you're very unlikely to invest in geothermal energy again and you're very unlikely to recommend to your fellow financial companies to invest in geothermal, so that’s the reputational setback.
That reputational hazard and financial risk associated with open-loop systems is a big problem for the geothermal business. I think that's why the business hasn't proliferated. Those are big setbacks, but also the awareness of a new system. That's one of the reasons I'm talking to you today is to spread the word within the energy business that the new closed-loop solutions are the “energy solved,” for want of a better expression. Geothermal energy is everywhere. As I've already mentioned, it's very hot in the centre of the earth, 6,000°C. That temperature can be gained everywhere. So really the awareness is a major setback.
But to answer the second part of your question, regarding young professionals and how they can help. Well, we need engineers, we need geoscientists, we need tradespeople. The geothermal industry is such a broad spectrum and requires so much. But above all, and this is something that young professionals really can help with, is we need enthusiasm and that's something that I am seeing in vast quantities from people of your generation.
In order to do that, we need to expand wind, we need to expand solar. But above all, in my view, we need to expand geothermal energy. At the moment, geothermal energy is only accounting for about 0.3% of global energy consumption. It's nothing. But there's potential to be everywhere. So, what we need are young professionals to jump in and to embrace geothermal energy, to understand geothermal energy, and to become enthusiastic and help people like me spread the word and to get the industry proliferating the way it can be.
Mrigya: Right. Okay. I remember in the first part of the answer, you did mention that there is a lack of awareness, the technology awareness about the closed-loop system. Regarding that, I would like to ask when was this technology developed?
Andy: Well, it's moving fast. Closed loop is nascent. There are a few projects around the globe, but for example, the company I work for, CeraPhi Energy, our first energy is going be produced in the next few months using closed-loop technology. This is one of the fantastic parts of closed-loop technology because, as I've mentioned, it's single well. Then we can take existing wells, whether they're geothermal wells which have failed, or oil and gas wells, which is of course relevant to SPE, and we can repurpose, we can put in a closed-loop solution, and we can gain geothermal energy at surface and use that for whatever we want to use it for.
In the case of oil and gas wells, there are some very hot oil and gas wells which are at the end of their life. We can take out the oil-well completion. We can put in geothermal-well completion, for example, and we can harvest geothermal energy at surface from a well, which was drilled a few decades ago.
That is a game changer. It's a really big deal. For example, our first project is going be in the UK. You take a well, it doesn't have to be very hot, let's say 70°C at the bottom of the well; we can harvest 50°C, 55° at the surface, and that heat can be used for so many different purposes.
Most people think about geothermal energy, and they want electricity, but that's an inefficient way of using geothermal energy. To convert one energy form to another is wasteful. So, we do our best to persuade people to use direct heat. For example, it can be used for glasshouse projects, which provides food security; it can be used for heat; and it can be used for district heating and cooling for residential purposes. And it can be used for direct industrial use. If you think about just about any industrial process, it requires heat at some point which varies depending on the particular industry. For example, sugar mills, breweries, and distilleries require heat, as do cement factories. The list goes on and on. Heat is required in so many different degrees and different forms. Also, for cooling. It’s used for sterilizing, for cooking, for distilling—all of these different things. So, we always lean towards the use of direct heat and that's something that is going to become more and more common as we go through time.
Mrigya: Right. That makes sense. I am really interested in the idea you mentioned about using wells that are at the end of their lives for harvesting geothermal energy. So, is there anywhere that a particular oil and gas company, or oil and gas company in collaboration with a geothermal energy company, is carrying this out?
Andy: Yes. I'm doing my very best not to shamelessly advertise the company that I work for, but in the UK we're about to do this for the first time. And it’s something which is not complicated, and as I've already mentioned, there are other companies that do the same thing.
But this is somewhere that the use of oil and gas technology married with existing geothermal technology is solving a world energy problem. The collaboration of these two industries is going to solve geothermal energy and it's not difficult. Most people from SPE will know how wells work. The oil and gas business has drilled somewhere between 10 and 20 million wells globally. We have a vast amount of knowledge of how wells work, and how when an oil and gas well has got an issue, it is worked over, that the problem with its completion is rectified and then it goes on producing again.
What we are doing in the closed-loop world is looking at it from a slightly different perspective. We're looking at the oil and gas completion and saying, “Well, it’s not useful anymore. Let's just take it out.” And that's a relatively simple process. It's done every day by oil and gas companies.
But we're taking out that oil and gas completion, and we're just replacing it with something very similar. But instead of harvesting oil and gas, we're harvesting heat. In some cases, it's a simple downhole heat exchanger. In other cases, we circulate a fluid around the well. It depends on the design of the well. Going back to your question, we are going do it first in the UK, but the UK only has a couple of thousand wells onshore. We are then going to move somewhere else.
Mrigya: And I'm sure this saves a lot of the cost for these projects?
Andy: Yes. Enormously. And the biggest cost in geothermal energy is drilling the well. It's a simple thing when you think about it: you have donor wells across the globe sitting there doing nothing. There are many oil and gas wells which have basically exhausted their useful life and they're just sitting there. Many of them are waiting to be plugged and abandoned by the oil and gas companies who own them. Now, that's expensive. So, imagine rather than paying $500,000 to $1.5 million to plug and abandon this, you just take that money and spend it to repurpose the well to a geothermal producer. Then you have turned a liability into an asset.
That's something that is very attractive to a great many oil and gas companies. But then, look at the environment, social environment, and social governance benefits which can get passed onto the oil company or the gas company, and to the local community. You can provide district heating to the local community. You can provide glasshouse projects to the local community. They're relatively inexpensive and these will help provide food security. But one of the favorite things it produces as far as I'm concerned is employment because these projects require people to manage them. They require people to work in the geothermal plant and to run the glasshouse projects. We can do desalination and that desalination in turn could lead to irrigation for agricultural systems. There are huge benefits, and this can all be done from existing wells. And if you think about how many: I've already referenced 10 to 20 million wells around the globe, and most of those are onshore.
Mrigya: You think about the benefits, they are huge. That's all really exciting and optimistic. It provides a nice, optimistic outlook towards the future. Which leads to my next question. So, the entire world today is trying to go to net-zero emissions. To not let the global temperature increase by more than 1.5°C, and they've set a date for this close to 2050. How do you see geothermal energy developing in the next 3 decades and what would be the critical geographical regions in the world?
Andy: The first region is going to be North America, because it already has so many onshore wells drilled, right? And my view is that repurposing of existing wells, not just oil and gas wells, but also failed geothermal wells, is going to be a huge source of not free energy, but it is cheap energy.
It's also carbon dioxide-free energy, right? So, North America, particularly the US if you look around Texas, they've got more than a million wells onshore. I mean, that's huge. But then add to that the fact that the US government is paying attention and is providing finance for various aspects of geothermal energy.
I think that the US would be the first place for various reasons, including those I’ve just mentioned. If you look at the energy industry, it is based in or around Houston. It’s going to build from there. But that’s where it starts. It will grow everywhere. For example, in India you have the most fantastic geothermal gradients. You also have existing wells. Those existing wells in India can be repurposed. But you also have these great geothermal gradients where we can drill new wells. So, I think the business will start with repurposing and then it will expand to new closed-loop wells because they guarantee production wherever they go.
My view of 2050 is that there will be a proliferation of geothermal energy. It’s possible to have a geothermal energy hub in every village, town, city, and for it to grow and grow. If you look at consumption of energy, where I am, the UK, 1 MW of electricity is enough to supply 2,200 houses, one well. In India, because the fantastic gradients can probably provide a megawatt or more of electricity, add to that the direct heat, it's tens of megawatts potentially of thermal energy. You can use a single well to feed a community. Heat for district heating and cooling. Heat for glasshouse projects, heat for desalination, and therefore irrigation. You can use the electricity for green hydrogen, for direct electricity for industry, for heat for industry. It’s a tree which just keeps growing. There are so many things everywhere that require energy. Geothermal is the answer and that's the exciting thing. Then I see, for example, it's embryonic right now but this business is going to grow and grow, and the great thing is it’s existing technology which is just being put together in a slightly different way. It's not some fantastic space age technology, which needs to be developed over decades. It's here, and that's the exciting aspect of it.
Mrigya: Thank you for answering that question. And with this, I have come to the end of my last question, but it was a really informative session, and you were right: I do think that there is a lack of awareness amongst people about how geothermal can be leveraged. And I do hope that through this session, you are able to spread awareness about the same. Are there any closing comments from your side?
Andy: Yes, of course, because this is a young professionals’ The Way Ahead magazine, I would encourage everybody in SPE to think about wells and to think about how hot they are. Think about what you can do with them. Think about the fact that a very simple solution can take what we have already and repurpose it.
The skills of people from SPE will very seamlessly pass into closed-loop geothermal energy. So yeah, we do need oil and gas. Of course, we do, and we're going to need oil and gas for a very long time. But I want to see us reducing our reliance on oil and gas. Look at geothermal energy, think about a career in geothermal energy.
Come and help us. You can help us do our job. Do drop me an email, contact me through LinkedIn. I am happy to talk to anybody about geothermal, anytime. Spread the word, spread the enthusiasm.
Mrigya: Thank you so much, Andy. It was such an insightful session. I hope it was really fruitful for our listeners. And thank you for your valuable time and sharing your experience and expertise.
