Podcast Summary
Geothermal power challenges: Despite being a clean and firm energy source, geothermal power's limited availability in economically viable locations and high costs have hindered its growth as a significant decarbonization tool
Geothermal power, a clean and firm energy source, has historically faced challenges in expansion due to its limited availability in economically viable locations and high costs. However, recent years have seen renewed interest in geothermal, with advancements in next-gen geothermal technologies aiming to widen its availability and lower costs. In this podcast episode, Dr. Roland Horn from Stanford University discusses traditional geothermal power technology and the challenges it has faced. He explains how geothermal power is generated through the earth's heat and how its limited availability in specific locations and high costs have hindered its growth as a significant decarbonization tool. Stay tuned as we explore the next-gen geothermal concepts aiming to address these challenges.
Geothermal energy development challenges: Historically, cost and geologic suitability have been the major challenges for geothermal energy development, with uncertainty regarding the size and longevity of the resource being a significant cost driver.
Geothermal energy, derived from the Earth's heat, has been utilized for thousands of years, but modern applications, such as electricity generation and heating buildings, gained significant traction in the late 1950s. Geothermal resources are most effectively harnessed in geologically favorable locations, primarily in volcanically active areas with high temperatures, abundant water, and permeable rocks. The infrastructure required for a conventional geothermal project involves drilling a well to extract water or steam, running it through a power plant, and recycling it back into the ground. Cost and geologic suitability have historically been the major challenges for geothermal energy development, with uncertainty regarding the size and longevity of the resource being a significant cost driver.
Geothermal Energy Advancements: Recent advancements in geothermal energy include the transfer of oil and gas technology into geothermal, making Enhanced Geothermal Systems (EGS) a more practical and viable solution for addressing permeability issues in geothermal energy.
The expansion of geothermal energy, a significant global renewable resource, has been slower than hoped due to uncertainties surrounding geologic suitability and cost. Traditional geothermal methods have limitations, leading to the exploration of new, next-gen approaches like Enhanced Geothermal Systems (EGS), Closed Loop Geothermal, Super Deep Geothermal, and Hybrid Systems. EGS, first proposed in the 1960s, aims to address permeability issues by artificially creating pathways between injection and production wells. While it shares similarities with oil and gas extraction, it's not a one-for-one application. The process involves fracturing volcanic rocks, which are harder and more brittle than sedimentary rocks used in oil and gas fracking. Despite its long history, recent advancements include the transfer of oil and gas technology into geothermal, making it a more practical and viable solution.
Geothermal Innovations: Companies like Fovo Energy are pioneering Enhanced Geothermal Systems (EGS) and Closed Loop Geothermal to expand geothermal energy production and make it more accessible and cost-competitive with other sources.
The energy sector is seeing innovation in the form of Enhanced Geothermal Systems (EGS) and Closed Loop Geothermal. EGS, as discussed, is a promising technology that could expand the geographical accessibility of geothermal energy by reducing the need for high permeability. Companies like Fovo Energy are proving this technology through projects in Nevada and Utah, with plans to scale up to 400 megawatts. Closed loop geothermal, on the other hand, involves creating permeability by drilling holes and connecting them to create a network for fluid flow. This technology holds the promise of expanding geothermal energy production in areas with minimal natural permeability. Both EGS and closed loop geothermal are important steps towards making geothermal energy more accessible and cost-competitive with other sources.
Closed-loop geothermal economics: Despite technical feasibility, closed-loop geothermal energy's high cost due to poor thermal conductivity in rocks and need for numerous drill holes makes it economically unviable compared to other energy sources and superdeep geothermal energy.
The economic viability of closed-loop geothermal energy, a form of geothermal energy that uses a closed system to extract heat from rock, is a significant challenge. Unlike Enhanced Geothermal Systems (EGS) where heat is extracted through long fractures in the rock, closed-loop systems rely on drilling numerous holes to extract heat through conduction. However, rocks are poor thermal conductors, making it difficult to extract significant heat from a large volume of rock through a single hole. As a result, the cost of closed-loop geothermal energy is currently higher than other energy sources. The first commercial pilot of closed-loop geothermal energy in Germany is planning to drill 80 kilometers of holes, which is feasible but expensive. The challenge is not a technical one but an economic one. Superdeep geothermal energy, which involves drilling deep into the earth to extract heat from extremely hot areas, is technically feasible but the economics are more advantageous due to the higher energy output per well. Traditional geothermal wells vary in depth, with an average of 7,000 to 8,000 feet (2 kilometers), while EGS requires drilling deeper, around 4 to 5 kilometers. Supercritical geothermal energy, a type of superdeep geothermal energy, requires drilling even deeper to extract heat at very high temperatures and pressures. The deeper the drilling, the higher the energy output and the lower the cost per unit of energy.
Deep Geothermal Challenges: To increase efficiency and compete with traditional power sources, deep geothermal energy requires drilling deeper and accessing higher temperatures, but this comes with significant technical challenges such as handling corrosive and acidic fluids, improving drilling, materials, cementing, and completion technologies, and overcoming the hurdles to make super deep, super hot geothermal a reality.
The future of geothermal energy lies in drilling deeper and accessing higher temperatures to increase efficiency and compete with traditional power sources like coal and nuclear. However, achieving this comes with significant technical challenges. While some supercritical geothermal wells have been drilled, the industry is still working on developing the technology to handle the corrosive and acidic fluids that come with high temperatures and mineral-rich water. The dream is to unlock geothermal potential anywhere in the world, but the focus is on improving it in places where it already exists and has high temperatures. The technical hurdles include drilling, materials, cementing, and completion, as well as handling the corrosive supercritical water. The industry has been making progress over the last 50 years, but there is still work to be done to make super deep, super hot geothermal a reality.
Geothermal drilling advancements: Geothermal drilling advancements, including batch drilling and the use of polycrystalline diamond bits, are reducing costs and increasing efficiency, making geothermal energy more competitive and accessible. These advancements are expediting project development from a decade to as little as three to five years.
The geothermal energy industry is experiencing significant advancements through innovative scientific approaches and drilling technologies. These developments aim to address technical challenges and reduce costs, making geothermal energy more competitive and accessible. The application of oil and gas drilling techniques, such as batch drilling and the use of polycrystalline diamond bits, have been instrumental in bringing down drilling costs. The EGS project in Utah, for instance, is drilling multiple wells at once, reducing drilling times by a factor of two or three. Conventional geothermal projects, which previously took a decade to develop, may now be expedited to as little as three to five years due to these advancements. However, to further accelerate the development of geothermal energy and meet decarbonization goals, it is crucial to have more projects in various geologies come online.
EGS exploration opportunities: Despite geological challenges, potential EGS exploration areas exist and could significantly contribute to the global energy transition. Finding the right geology is crucial for success.
There are still potential areas for Enhanced Geothermal Systems (EGS) exploration, despite some geological challenges. While conventional geothermal energy might not be feasible in certain locations, EGS could offer an alternative solution. The key is finding the right geology - rocks that haven't broken up too much and are hot enough. Dr. Roland Horne, a professor of Earth Sciences at Stanford University, emphasized that there are places ready for development but require exploration efforts. He also mentioned that companies and individuals should seize the opportunity to go out and make these projects a reality. EGS could contribute significantly to the global energy transition, and it's essential to continue exploring its potential. This episode was a production of Latitude Media, supported by Prelude Ventures, a venture capital firm backing climate innovation.