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June
10
2021

Natural Gas Is The Secret To Scaling Geothermal Energy
Haley Zaremba

No matter where you are on Earth, you are situated right on top of a potential clean energy production hub. This is the argument at the heart of the push for expanding geothermal energy, a renewable and carbon neutral form of energy production that relies upon the heat naturally produced under the ground to create turbine-turning steam or to pump straight into residences as well as commercial buildings. 

Worldwide, the average “geothermal gradient” is about 30 degrees Celsius per kilometer(which translates to 86 degrees Fahrenheit for every 0.6 miles), meaning that for every kilometer deeper you drill into the Earth, the surroundings increase in temperature by about 30 degrees. A geothermal power plant will drill one or two miles deep under the surface of the Earth in order to extract steam or hot water, bringing it to the surface to turn it into energy. 

Most geothermal power plants position themselves where the Earth is hotter much closer to the surface, such as areas with hot springs, geysers, or volcanic activity. Volcanic Iceland, for example, gets an astonishing 66% of its energy from geothermal sources. Yes, having access to hot water and steam right under the Earth’s surface makes geothermal energy much more economically feasible and logistically practical. But what if that didn’t matter? What if geothermal energy were less limited to being within proximity of hot water and steam? What if heat was all it took, and a geothermal energy plant could be created absolutely anywhere on Earth?Related: Oil Prices Fall Following Large Fuel Inventory Build

Many scientists and entrepreneurs are working on solving just this problem, and the solution some of them have turned to is a surprising one: natural gas. Some forward-thinking companies have devised closed-loop geothermal systems which drill into the ground, allowing the Earth’s naturally emanating warmth to heat a liquid, creating vapor which in turn creates rotational energy, and then allowing that vaporized substance to condensate and turn back into liquid. Wash, rinse, repeat. The thing is, that liquid is not water, but natural gas such as butane or pentane, which each have a much, much, lower boiling point than water, meaning that less heat is needed and wells don’t have to be dug as far under the ground. 

For now, these technologies are prohibitively expensive. But once they become cheaper and more scalable, these natural gas-based geothermal methods could have potentially huge benefits for the global energy landscape and for the climate. And despite the fact that these systems are quite pricey now, they still hold a certain allure for countries that are rich in capital but short on space, as well as where prices of heat and energy are already higher than average, as these closed-loop geothermal plants take up considerably less surface area than other renewable energy sources such as wind and solar farms. This means that we could be seeing the spread of gas-based geothermal energy in countries such as Germany, the Netherlands, or Japan. 

Already, the companies making inroads in this novel industry are catching the attention of the oil and gas sector. One such company, Calgary, Canada’s Eavor, received funding from both BP and Chevron in its last round of investing back in February. 

While the idea of mixing fossil fuel consumption with an energy production method as clean and renewable as geothermal is certain to cause plenty of consternation and well-deserved scrutiny, a closed-loop system which heats residences and businesses without ever actually combusting the natural gas involved is a definite improvement for greenhouse gas emissions and a community’s overall ecological footprint. What’s more, it could potentially be a key component to a transition away from fossil fuels and toward a cleaner, greener energy future without going cold turkey on oil and gas and leaving that sector’s labor force out in the cold. 

By Haley Zaremba for Oilprice.com

Haley Zaremba is a writer and journalist based in Mexico City. She has extensive experience writing and editing environmental features, travel pieces, local news in the Bay Area, and music/culture reviews.

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