“Fracking”. The dirty word that spurred consternation, protests, and innumerable documentaries. In an odd twist “fracking” and renewables, specifically geothermal energy, are in the early stages of forming an unlikely pair. The controversial technique may just be the missing piece toward broadly commercializing geothermal energy, which is both reliable and has energy storage potential. Independent oil and gas producer Devon Energy (DVN) recently invested $10 million into privately held Fervo Energy, a company that seeks to use fracking technology to expand geothermal energy’s reach. Turns out geothermal energy’s obstacles are similar to obstacles oil and gas producers faced 15 years ago, only the former will get the benefit of all the lessons learned by the latter.
Before we look at Fervo it makes sense to explain a little bit about geothermal energy. Geothermal energy is heat energy from the earth, such as naturally occurring reservoirs of hot water at varying temperatures and depths below the Earth’s surface. “Old Faithful”, the famous geyser in Yellowstone National Park, is an example of geothermal energy. The majority of today’s harnessed geothermal energy is found in areas like Yellowstone, where companies drill into hot spots and direct steam through turbines to generate electricity. Unfortunately, these hot spots can be few and far between and as a result geothermal energy has been a rounding error in energy supply.
To date, geothermal energy production has relied on geological formations with high porosity and permeability that forms pockets that can then be exploited, similar to conventional oil and gas production prior to the shale revolution. For oil and gas the combination of horizontal drilling and hydraulic fracturing (“fracking”) made tight rock formations economic, thereby changing the game. In short, horizontal drilling and “fracking” created the necessary pathways allowing molecules to travel into the wellbore.
Companies like Fervo are now aiming to apply the same techniques to geothermal energy. That is, forcibly create the missing porosity and permeability that will then allow water/steam to travel up to the surface. It’s the same concept. Only in theory the geothermal energy industry should be able to skip some of the trial-and-error that beset the oil and gas industry for years before it became economical.
Now comes the cool part. The three main things that get us excited about this unlikely pairing are:
- the opening of exponentially more acreage for geothermal energy
- re-purposing abandoned oil and gas wells
- the potential for geothermal energy to be used as energy storage
The opening of exponentially more acreage for geothermal energy. While admittedly yours truly is not a geologist, the right conditions for geothermal energy (heat + pressure) are likely only a question of depth. Therefore, the potential for geothermal energy is everywhere and anywhere in theory. This compares to oil and gas which required loads of decaying material in a specific spot over the course of millions of years.
Re-purposing abandoned oil and gas wells. Why re-invent the wheel? There are roughly 120,000 abandoned oil and gas wells in the United States, and each of them may represent a short cut for those “fracking” a geothermal solution. Once again knowledge gleaned from decades of horizontal drilling and “fracking” should give the geothermal energy industry a strong foundation to build on. There is also the added benefit these defunct wells may have infrastructure already in place (e.g., roads, power lines, pipelines, etc). Finally, the owners of these wells are also likely aware of higher monetary penalties that are coming in 2024 for methane leaks ($900/ton).
The potential for geothermal energy to be used as energy storage. The concept is fairly straightforward even if it will likely take time for costs to get competitive. The basic idea is you inject lots of water into a geothermal well and build the well pressure to a very high level, and then close the valve. When you need energy, open the valve. Voila, energy storage! While this concept is in the experimental phase there is a theory that an enormous amount of pressure built up over several days could then be released over several days, a.k.a. long duration energy storage. As we’ve written before, energy storage is the holy grail of energy transition.
In conclusion, the world and your world are often flipped upside down. Looking back twenty years from now nothing would be more ironic than “fracking” being known as the missing piece to the energy transition puzzle. The technology that helped achieve Net Zero. It’s getting hot in here!