Innovative technologies now able to exploit ultra deep geothermal energy could give us access to a permanent supply of renewable heating, cooling and power, provided anywhere, as well as providing a future-proof transition for skilled oil and gas workers. But this requires a coordinated European strategy and targeted support measures to accelerate commercialisation.
Russia is a key supplier of fossil energy, accounting for 40% of the EU’s natural gas consumption, 27% of its oil and 46% of coal in 2021. At present, European policy makers seek to urgently reduce Europe's dependency on fossil fuels from Russia. The nexus between European security and local access to sufficient resources of green, renewable energy has become evident. In the short term, energy efficiency and sourcing from other exporting countries will play an important role. In the medium to long term, reducing Europe's dependency on fossil-derived energy is the only viable option to increase energy security and to achieve the European Union`s climate targets.
Geothermal energy complements other renewable sources because it provides energy on a continuous basis. It thus reduces the need to build large energy storage capacities, making it an ideal substitute for conventional fossil-based heat and power supply in many applications.
The Earth’s crust contains a consistent layer of hot rock, not economically accessible with today’s conventional drilling applications. At a depth of 10km there is 50,000xmore energy than all known fossil fuel reserves. Ultra-deep geothermal is a large-scale baseload solution to replace fossil fuels that is available anywhere, anytime while making use of the technology, know-how, and highly skilled workforce of the oil industry. Moreover, deep geothermal doesn’t rely on rare-earth minerals – in fact, it can be a sustainable source of lithium –thus avoiding the risk of creating new global dependencies.
Geothermal energy is created by piping hot water up from underground. After converting the hot water to power, the water is piped back down. Geothermal power plants can provide combined heat and power (CHP) and even cooling.
This detailed Life Cycle Assessment (LCA) conducted by Planet A Ventures reveals that geothermal energy can substantially reduce GHG emissions in comparison with fossil-based generation. The net reduction exceeds 430gCO2-eq. per kWh if geothermal replaces natural gas, and 1kg CO2-eq. per kWh when hard coal, lignite or oil are displaced. Geothermal electricity reduces GHG emissions by 99% compared to the conventional electricity supply it displaces. If non-condensable gasses are included, the average reduction of GHG emissions amounts to 88%.
And lastly, deep geothermal energy does not pose any uncontrollable risks to the environment, according to a study of the German Federal Institute for Geosciences and Natural Resources (BGR) that analyzed 56 studies and simulations from all over Europe.
Engineering hurdles have prevented a vast move into geothermal energy. Most geothermal energy can be harvested at depths of5km or more. Hard rock (granite) is usually reached at around 3km of depth, and after this point costs rise exponentially due to highly decreased durability of contact drill heads. Challenges of deep drilling include the need to replace drill heads after 0.5-1m of drilling. In a process known as “tripping” drills need to be pulled up one-by-one to replace drill heads - this can take a crew 32 hours to complete at a depth of just 3 km. The deeper the hole and the harder the rock, the more tedious and costly tripping becomes.
In addition to hard rocks, these depths contain extremely high temperatures and pressure levels (more than 370 degrees C and220 bars of pressure). These conditions create what is known as super critical water, a fourth physical state of water with 10x enthalpy, meaning the amount of heat that water can hold. Geothermal wells at a temperature of~400 degrees C produce 10 times more energy than those at 200 degrees C.
In order to exploit ultra-deep geothermal energy the cost of drilling must be slashed significantly. Drilling of geothermal wells can make up 30-50% of the total project costs. Traditional drilling technology has seen a significant downward sloping cost over the past decades, however it has been optimised for sediments rather than hard rock, simply because there are no fossil fuels to be found in hard rock.
Fortunately, a handful of startups are developing technologies that will enable linear drilling cost to any depth. There are several novel technologies that lead to faster drilling and reducing drilling costs for geothermal projects, allowing the energy price to remain competitive even at deep depth. These innovations open up the potential to make geothermal energy accessible everywhere.
Quaise Energy, based in the USA, has developed a drilling method which uses millimeter waves to transfer large amounts of electromagnetic energy through a fibre optic cable which is inserted into the well. Quaise Energy is aiming to demonstrate their technology in the field by2024 (currently around technology readiness level TRL of 4).
GA Drilling, a Planet A portfolio company based in Bratislava, Slovakia, has come up with Plasmabit®, a new type of contactless drill that destroys hard rock using high-powered plasma pulses. Compared to legacy mechanical drilling, this contactless technology is key, as it overcomes the “tripping” challenge.
GA Drilling has developed a complete drilling system over the last decade and plans to drill its first wells within the next 18 months, which corresponds to a TRL of 5-6.
Fervo Energy is a US-based company whose technology combines horizontal drilling, distributed fiber optic sensing and advanced computational modelling.
NOV’s next generation PDC drill bits have been adapted for geothermal environments to be able to drill for longer.
Greenfire Energy (USA) has developed a closed-loop technology which can be retrofitted in existing wells to transport geothermal heat. The technology works by circulating fluids through a sealed system for economical energy extraction.
AltaRock Energy (USA) develops enhanced geothermal systems, integrating state of the art drilling technologies, well completion and reservoir development into a complete system.
Sage Geosystems (USA) has developed a modelling tool which integrates surface and subsurface data to identify the most appropriate geothermal system for heat extraction.
GeoVision 2019 puts the startup cost of geothermal power projects at $30 and $60 per megawatt hour. But these cost estimates do not take into account the novel technologies with which prices of around $20 per megawatt hour are becoming feasible. While land-based wind and utility-scale solar’s startup costs are lower at between $17 and $21 per megawatt hour, these figures don’t account for energy storage costs, which today sit at about $150 per megawatt hour of electricity.
For the EU to meet its 2030 renewable energy targets, diversifying the energy mix by deploying new technologies such as geothermal is essential.
According to the International Energy Agency (IEA) geothermal energy needs to grow by 13% each year if we want to achieve climate neutrality by 2050. The global use of geothermal energy increased by just two percent in 2020, however - and most new installations were located in Turkey, Indonesia and Kenya. Predictions for the geothermal share in the 2030 energy mix remain small.
To create the right market environment to scale advanced geothermal, we make the following proposals:
Each Member State should set an indicative target of at least 5% of new renewable installed capacity in RED III for innovative renewable energy. This must be followed up by appropriate financial and regulatory frameworks in member states to deploy new renewable energy technologies to market in the coming decade.
Industry players are calling for a European Strategy on Geothermal energy which will identify barriers; propose measures to accelerate deployment, including heating &cooling infrastructure; develop and maintain high environmental standards; de-risk private investments; accelerate sustainable mineral extraction and encourage crowding-in financing facilitate a pipeline of projects that can help deliver on the EU’s new 2030 climate and energy targets.
Sub-targets and dedicated incentives for strategic emerging innovative technologies are vital while they cannot compete on cost with more established solutions. The optimal energy mix differs by state, but each member state should define an appropriate sub-target for geothermal energy, together with a demand-pull incentive framework to prompt private investment in the sector (this should be facilitated at EU level to allow tenders by technology category).
Planet A and Cleantech For Europe
May 23rd, 2022
Contact: Lena Thiede, firstname.lastname@example.org
Thanks to Nicolas de la Vega and Greg Arrowsmith, EUREC, as well as Dr. Benedikt Buchspies, Planet A Science Team, for helpful inputs to this article.
Planet A is an investment fund partnering with European green tech start-ups that have a significant positive impact on our planet while building scalable businesses globally. Our mission is to contribute to an economy within the planetary boundaries. We support innovation in four key areas: climate mitigation, waste reduction, resource savings and biodiversity protection. First in the European VC world we offers scientific impact assessments to support our investment decisions and empower founders to manage and improve their impact. A wide network of experienced founders and experts support our portfolio companies. Investments include Traceless, Ineratec, C1, goodcarbon, GA Drilling and Makersite.