GTK`s Alan Bischoff Believes that Research on Deep Geothermal Energy Deserves a New Endeavour

From Brazil to Finland via New Zealand

Originally from Brazil, Alan Bischoff became a researcher at Geological Survey of Finland (GTK) through many twists and turns. The decision to move with his family from New Zealand began with the recommendations of his Nordic friends and colleagues. ‘You’ll like Scandinavia’ said his Norwegian professor and friend when Bischoff and his Finnish partner were thinking about the next research position.

After five years working as an exploration geologist offshore in Brazil, Bischoff landed in the “Down Under” for holidays. Twelve years went by in New Zealand – first travelling and learning English, then in various shorter job positions, and finally as a geologist in a gold mining company. ‘I visited and never left,’ notes Alan. In New Zealand, he also applied for postgraduate studies at the university and completed his PhD. During his last few years in New Zealand, he worked in a research group at the university investigating the geothermal potential of volcanic reservoirs, among other energy geoscience technologies.

‘You never decide to move to another country based on just one thing. I’d heard good things about working at GTK from many acquaintances, and after my daughter was born, I started looking for a more stable alternative. I became interested in GTK because they combine high technology with cutting-edge research. I was excited because GTK is a place where people really want to push forward for new knowledge,’ Bischoff says.

How did you come to research geothermal energy at GTK?

Alan Bischoff: Because of all the recommendations, I started following open positions at GTK. First, I applied for a position in the Geophysics laboratory, and the interview went really well – we talked for a couple of hours about everything else but the open position. Finally, Fredrik Karell, now the head of that unit, realised that this wasn’t the right place for me but that I should talk to Team Manager Nina Leppäharju and Chief Expert Teppo Arola from the GTK’s Geoenergy group. So I started following open positions in Geoenergy, and I ended up applying for the position of Senior Scientist.

The interview with Nina, Teppo and Head of Unit Hannu Lahtinen went brilliantly again. I already felt like part of the team during the interview. Research on deep geothermal energy seemed to be at an interesting stage at GTK, and something I could contribute to because of my multidisciplinary background. One of the main challenges in Finland is that one must drill several kilometres to find suitable temperatures for large-scale geothermal production. And finding solutions to harvesting the Earth’s “deep heat” requires scientific innovation across several geoscience topics including geophysics, structural geology, and petrophysics.

What makes geothermal energy research interesting right now?

In general, energy research priorities have really shifted since I started working as a geologist. For over a century, petroleum exploration permeated through geology schools and many alternative technologies could not become commercially competitive. But, our current climate-change challenges are shifting this scenario. Sustainable solutions, for the environment and the future, are really on the surface now.

Ten years ago it was very difficult for an energy geoscientist to find work opportunities beyond fossil fuels. We’ve seen massive growth in research into hydrogen and low-carbon energy solutions. But the greatest advantage of geothermal energy is its baseload reliability: different from other alternative energy sources such as solar and wind which rely on climatic conditions for energy production, geothermal is available 24/7.

I became interested in exploring geothermal energy in New Zealand, which, like Iceland, has great conditions for geothermal and a long history of using it. Geothermal production in active volcanic and rifting areas is going well. Our remaining questions now involve how to increase production beyond these high-temperature areas. The Fennoscandian Shield (the geological setting of Finland) is one of those lower-temperature areas that will immediately benefit from increasing the uptake of geothermal resources for space heating and industrial purposes. I feel lucky to be able to research things that have a major impact on society.

Geothermal energy is widely used in volcanic regions of the world, like New Zealand. What observations have you made about the use of geothermal energy in Finland?

Conventional electricity production from geothermal sources is an established technology and industry where heat is more easily accessed near the surface. But geothermal energy offers multiple opportunities, from shallow heat systems for space heating and cooling to multi-megawatt power plants.

In Finland, shallow ground heat production (aka geothermal heat pumps) is a remarkable success story, even though we’re in one of the most challenging places in the world for geothermal energy research and application. According to the Finnish Heat Pump Association, today, over 150.000 geothermal heat pumps are installed in the country, and the numbers are growing substantially. Shallow geothermal energy production in the Nordic countries accounts for a very well-established industry that can already walk on its own feet. I was surprised that in Finland there are new individual homes sold with ground heat system already in place, demonstrating the competitiveness of this market.

Due to the cold climate here, we’re used to using ground heat to heat individual homes from a few shallow boreholes, at most. However, increasing the reward of geothermal developments requires drilling deep, and there lay the challenges: low geothermal gradient and low permeability. Finland`s bedrock is ancient and cold, and it has a thick lithosphere. Now we need to demonstrate how to find or create sufficient permeability to harvest the “deep heat” at economical rates. The Finnish bedrock is tricky, but I believe it can be tamed.

The most interesting issues now are the scalability of geothermal energy production to regional solutions, making use of deep geothermal energy, and developing production technologies that will create competitive markets. There’s plenty to research there.

The greatest advantage of geothermal energy is its baseload reliability: different from other alternative energy sources such as solar and wind which rely on climatic conditions for energy production, geothermal is available 24/7.

What are the challenges to the wider use of geothermal energy in Finland?

In Finland, there are actually two key factors: heat production and technology. Deeper in the bedrock, heat production increases significantly, reaching 100° C at a depth of 6–7 kilometres, but so do the costs and risks associated with drilling boreholes. Drilling a deep hole takes several months and costs millions. But if we stay at more moderate depths, we need more boreholes and a larger borehole heat exchanger (BHE) area for a higher heat production. Our models suggest that in more densely populated areas, this may not be possible.

We therefore need to be more accurate in assessing the geological conditions deep in the bedrock, the geothermal energy potential of a given area, and how to make energy production more efficient. At the same time, we need to reduce the costs and risks of drilling and production technology. Every unprofitable experience with deep geothermal boreholes reduces the industry`s confidence in new experiments.

Achieving this high-level of accuracy will require further research into indirect geophysical methods to find deep permeable zones at the same time that we will need more direct information from drillholes to evaluate the petrophysical and thermal properties of the deeper Fennoscandian crust. Collectively, this knowledge will allow us not only to correctly evaluate the natural geothermal resources beneath Finland but also how to design new technologies for heat extraction. For example, novel Enhanced Geothermal Systems (EGS) technology will strongly benefit from more accurate information about the deep Fennoscandian crust. Presently, only a dozen of boreholes have penetrated into deeper Finnish environments.

I think GTK is on the right path: promoting innovation, supporting baseline research, and creating cooperation opportunities. Working with a network of public operators, research organisations and businesses is critical to developing new low-carbon technologies and the only way to tackle the multiple issues of deeper geothermal exploration.

The Geoenergy group is also involved in GTK’s self-financed Koillismaa Deep Hole project that focuses on deep bedrock research. What makes the Koillismaa project interesting to a geothermal energy researcher?

I think that the initiative that GTK has for drilling the Koillismaa deep hole is exactly what we need in terms of new science. Now, Koillismaa is bringing together a critical mass of researchers to study the deeper subsurface. At the moment we have a limited amount of data about the deeper crust, and a small number of people working together towards common goals. I think Koillismaa has already achieved exciting goals by putting together our Geoenergy group with researchers from other units. In addition, Koillismaa is attracting national and international research partners such as the University of Turku and the University of Strasbourg (France). Having all these people in the same room talking, trying to resolve the same issues, is encouraging.

For geothermal energy researchers, a deep hole provides information on the actual (in-situ) conditions and rock types in the deep bedrock. We`re using the data we collect from the deep hole as a screen for new opportunities to find geothermal reservoirs in the deep Finnish crust. For example, we’ve been able to develop the capabilities and accuracy of the ADTS method to measure the in-situ thermal conductivity and other properties of bedrock at greater depths. Preliminary assessment of the drillhole data shows critical information to understand how heat and fluid migrate within the Finnish bedrock.

Geothermal energy production depends on the bedrock’s fracturing, porosity and permeability. The Finnish bedrock often consists of rock types with poor permeability. Hot water reservoirs don’t form easily within the bedrock, and fluid can’t move and circulate, which is essential for geothermal heat generation.

So far, our main discovery in the Koillismaa deep hole has been the high porosity and fracturing of the bedrock. Porosity is not a common feature of crystalline bedrock at these depths. In addition, we found that these porous and fractures have an important impact on the thermal parameters of rocks, which ultimately control how heat is transferred and stored in the crust. The results from Koillismaa are very promising. Now we want to know how the porous, permeable rock formed, and how the porosity has remained open in this deeper, pressurised environment. This has opened a completely new direction for our research.

What comes next? What does your future at GTK look like?

Great question. I have been at GTK for less than a year now, so I’m still building networks and trying to convince my colleagues in the direction of studies that I think would help us find geothermal resources more efficiently. My “bosses” have given me a lot of leeway and support for new opportunities, ideas, and resources, which is great. High-quality research requires time and experimenting.

I`ve been going around talking to my GTK colleagues – some of whom are retiring – to collect as much valuable information from them as possible. Everyone has been really friendly and open to sharing their knowledge. They have raised my understanding weekly, with the knowledge that they have accumulated in 30, 40 years. And this has been fantastic.

Now I want to focus my research on geothermal reservoirs located at lower-temperature crystalline settings. We have other deep holes in Finland in addition to Koillismaa. I am sure we can keep squeezing a lot of good information from them. We should collect samples and measure in deeper, actual conditions. The deeper we go into the bedrock, the more complex the system becomes. Most of my colleagues are modellers. I want to provide them with more accurate, real data on the deeper conditions of the bedrock to improve our models of deep geothermal energy potential and our understanding of the prevailing parameters.

The future of geothermal energy in Finland is at an fascinating stage. GTK offers a good repository of baseline research data to build on. We can use Koillismaa and other deep holes to showcase industry operators how and why things work the way they do deeper down in the bedrock. Deep geothermal energy solutions, such as EGS and those based on artificial water circulation, also depend on this.

The research data should be open and available to all, so that stakeholders, decision-makers and businesses can understand why a particular solution didn’t work and how we might make it work. Finding energy resources on the deep Earth is risky and will require perseverance, but also offers an enormous reward: a constant domestic supply of clean and renewable energy to move our society and the economy.

 

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