Deep Geothermal Energy: Life's Origin & Future

Life on Earth may have risen from a geothermal pond. Photo: Donvictori0 | Adobe Stock

Geothermal energy is a source of life itself. Many scientists theorize deep hydrothermal vents on the ocean floor created the conditions for the formation of organic molecules, life’s raw ingredients. Others theorize organic molecules first formed on land in geothermal ponds, similar to those at Yellowstone National Park. If true, we are all descendants of a common ancestor brought to life by geothermal.

Geothermal energy also sustains life as we know it today. Plate tectonics, our planet’s magnetic shield, and many other natural processes rely on the Earth’s internal heat. Yet geothermal is more than just our past or present; it holds the key to our sustainable energy future.

While geothermal energy is hot, it is not new. Humans have benefited from geothermal energy for over 10,000 years, first at hot springs in North America. And in 1904, a plant in Larderello, Italy, was the first to generate electricity from geothermal. Since then, geothermal power production has been limited to regions like California, Iceland, and Indonesia, with accessible hot water and steam underground. This type is called hydrothermal, or conventional geothermal energy.

Now there’s a new frontier: creating a geothermal reservoir via Enhanced Geothermal Systems (EGS). Preexisting reservoirs of hot underground water are no longer necessary, just hot rock. The aim is to pump water through the hot rock and recover heat, generating electricity. EGS research began in the 1970s with the aim of expanding geothermal energy into areas previously out of reach.

The U.S. Department of Energy aims to 20x geothermal power production with EGS by 2035. Geothermal currently contributes less than 1% of total electricity in the U.S. and the world. But even a 20x increase won’t significantly move the needle. What’s truly needed is a bold breakthrough.

Geothermal is more than just our past or present; it holds the key to our sustainable energy future.

Deep geothermal is the ultimate frontier for EGS. The deeper and hotter you go for geothermal, the more power you get. Deep geothermal can produce up to 10x as much power as conventional geothermal by dialing up the temperature and pressure.

What does that look like? Conventional geothermal and lower-temperature EGS typically reach about 200°C, which is normal for most home ovens. Deep geothermal reaches temperatures in the 300-500°C range, which falls into the operating range of most commercial pizza ovens. These are extreme temperatures for drilling but are familiar in everyday life.

And the possibilities are mind-boggling. Harnessing just 1% of the world’s deep geothermal potential could produce more than 4x the anticipated global electricity generation capacity of 2050. The clean energy transition would effectively be over if we could reach just a small fraction of the resource.

Plus, deep is a relative term. Conventional geothermal reaches depths of about 2 kilometers (km) or less, whereas lower-temperature EGS can range up to 7 km. Deep geothermal is all about the 300-500°C range, which can be found as shallow as 3 km or as far as 20 km. But it’s not as deep as you might think.

On average, the depth from the surface to the core of the Earth is about 6,000 km, similar to the distance of flying from New York City to Berlin. In New York City alone, the Brooklyn Bridge is barely 20 kilometers from JFK Airport. If the Earth were an ordinary apple, deep geothermal drilling at its maximum would breach less than half the skin of the fruit.

The temperatures and depths of deep geothermal are radical for drilling but not for humankind. We’re talking about pricking less than half the skin of the Earth to generate clean electricity at pizza oven temperatures. The best part is that we can access deep geothermal almost anywhere on Earth to potentially eradicate energy poverty and the geopolitics of energy forever.

Scale is the difference between conventional geothermal and deep geothermal. Conventional geothermal is extremely limited by geography; deep geothermal faces fewer restrictions. Conventional geothermal collectively outputs gigawatts, enough to power cities. Deep geothermal could collectively output terawatts of clean power, enough to sustain large countries and the future of civilization.

Deep geothermal is a keystone of life on Earth; it’s the story of who we are and where we need to go. Next month, we’ll look at the key to accessing deep geothermal energy: millimeter wave drilling.

Energy is everything. At Quaise, we look at the big picture to see where the world is and where it needs to go. Today, fossil fuels still dominate global energy by a long shot. A smoother transition to clean energy requires a bold new vision grounded in science, scale, and speed. Join us as we explore the future of energy and the power of deep geothermal.