Geothermal energy is not exactly a new idea. It’s been used since Roman times. Scientists and practitioners have known about its potential for a long time, but it has yet to become a mainstream solution.

The last couple of years, however, have seen the investment viability and interest in renewable energies spike in response to demands from the public, the market, and energy industry shareholders themselves. There has been a cultural shift in priorities as a larger percentage of the population feels the tangible impacts of the climate crisis. Just in the past year, the word “geothermal” has been spoken by more people in more places than ever before in the 37 years I’ve been a geothermal energy practitioner.

Geothermal is finally having its moment.

How geothermal power works, in a nutshell

Geothermal power is a form of geothermal energy that works by tapping into Earth's natural heat deep below the surface. And there’s a lot of water in the subsurface, too, providing a convenient medium for extracting all that heat. In most places around the world, the deeper you go, the hotter it gets. However, in areas that are volcanically or tectonically active, nature has enabled higher temperatures at much shallower depths. 

Regardless of how and where hot water is found in the earth—whether near or far from any volcano—it can be readily extracted and used to generate electricity in two ways. In higher-temperature resources, geothermal steam  (a vapor) is supplied directly to a turbine generator. In lower-temperature resources, the produced hot water passes through heat exchangers that transfer heat to a fluid that vaporizes at a lower temperature than water—not steam in this case, but a different vapor. In both cases, the heat-depleted water is returned to the earth to begin the cycle again. 

The result? Significant generation of 24/7 power with minimal carbon dioxide (CO₂) emissions.

Yes, it’s about the money—but the calculation is skewed

Despite this potential, an ever-present issue remains: economics. Ignoring the costs of the environmental impacts that have led to climate change, geothermal power costs more to develop than other sources. As a result, those who are driven only by maximizing short-term profit have not invested in geothermal. 

But times are changing. The almost incalculable cost of climate change is driving investors, along with oil and gas (O&G) companies, toward geothermal power. While it might come as a surprise that part of the answer to a sustainable energy future is coming from the O&G industry, there is no doubt that it has all the adjacent expertise needed to make geothermal energy a viable solution—and to develop it at scale. 

It all starts with drilling.

If there’s one thing the O&G industry has figured out, it’s the complexities of drilling deep into the earth. Geothermal power uses a similar process but has a vastly different outcome: near-zero CO₂ emissions. Instead of producing their traditional hydrocarbons, decades of tech development, subsurface extraction, and resource management are being used to produce geothermal power. But this time, the only things being exploited are the vast stores of the earth’s renewable, replenishable heat. The extensive subsurface know-how of the O&G industry is being repurposed for our planet’s changing energy needs, putting geothermal in a prime position for our clean energy revolution. 

So, why is geothermal uptake so slow then?

Other options like wind and solar offer lower start-up costs, which is why they remain popular choices. But the intermittent nature of these solutions requires significant back-end costs for energy storage in the form of batteries. Otherwise, how would you use energy at night or on a calm day? When these and other maintenance costs are factored in, an investment in wind or solar is at least equivalent to if not more costly than geothermal (even if you ignore geothermal’s obvious advantages). 

But maybe the reason for slow adoption is not cost or availability, but instead a lack of understanding. Considering that the “g word” is being spoken more and more these days, I’m bullish on intelligent thinking about geothermal.