Unlocking the Earth's potential: 5 facts about geothermal energy

By tapping into the heat that lies beneath the Earth’s surface, we can make a vital contribution to a healthier planet. Here’s how.

Many of us will remember the excitement of studying volcanoes in school: learning how rocks can reach the mind-blowing temperatures of several thousand degrees Celsius.

Today, far from the simple models we built in the classroom, experienced engineers with extensive subsurface skills apply advanced technologies to safely harness the Earth’s heat as a clean, nearly inexhaustible energy source.

Geothermal energy is a local energy source, not affected by price fluctuations and is therefore predictable. It also makes us less dependent on energy imports. These qualities mean it has a huge potential to make a valuable contribution as we transition to a sustainable, low-carbon future. Here’s how it works – 5 reasons why geothermal is a key part of our transformation.

1. It can deliver heat and power

Today, geothermal energy is widely used for district heating, without the need for fuel or large power plants. In hydrothermal systems, hot formation water is produced from the subsurface. The heat is extracted via heat exchangers and the cooled formation water is reinjected into the subsurface, where it is warmed by the Earth once again. The extracted heat is used for heating houses, offices, hospitals and other buildings. The result is a reliable, local source of energy with no harmful emissions. By reducing dependence on imported fossil fuels, geothermal energy also improves energy security.

Going deeper into the subsurface or at places with a higher geothermal gradient, we find conditions that allow us to produce power from geothermal energy. There are several methods of doing this but, in principle, steam is used to run a turbine which produces the power.

2. It’s available 24/7 and it’s reliable

As we rethink and diversify our energy mix to embrace more sustainable solutions, geothermal energy has a pivotal role to play in ensuring a smooth, responsible transition.

Drawing on constant heat from the Earth’s subsurface, geothermal energy can deliver 24 hours a day, 365 days a year, regardless of the weather – a major advantage over more intermittent sources of renewable energy, such as solar or wind. This means that geothermal energy helps us to provide a consistent base load in our energy mix.

Geothermal energy is clearly a green energy source. Geothermal plants emit 99% less carbon dioxide than fossil fuel power plants of similar size. They also have a small physical footprint on the surface.

3. It’s in use across Europe and the rest of the world

Many countries are already using geothermal heat for district heating and, in some cases, to generate power. The world’s current power production from geothermal energy totals almost 17 gigawatts. In Europe, geothermal energy is primarily used for district heating.

In Vienna, our groundbreaking joint venture ‘deeep’ with Wien Energie is poised to supply 200,000 households with 200 megawatts of climate-neutral energy. An almost 20-million-year-old layer of rock at a 3,000-4,000m depth heats a reservoir of hot formation water to temperatures above  100° C. To this project, we bring decades of subsurface and drilling experience as well as our unique knowledge of the Vienna basin. On the surface side, our partner Wien Energie is operating one of the largest heat distribution networks in Europe.

4. It has enormous potential

With geothermal energy making up just 0.5% of the world’s installed capacity for electricity from renewables, there is still huge potential to make greater use of this almost limitless resource.

Drawing on technology and our expertise in subsurface engineering and geology, we aim to build a 4 TWh geothermal business by 2030.

In pursuit of this goal, we have acquired a 6.5% stake in Eavor Technologies, the world’s leading developer of closed-loop geothermal energy technology. The initial focus is Germany, firming up geothermal licenses and strengthening partnerships with utility companies.

As Angelika Zartl-Klik, Senior Vice-President of OMV’s Low Carbon Business explains, “We’re committed to leading the heat transition, with geothermal energy set to play a crucial role. We’re already working on projects to tap into its potential, and welcome collaborations with partners who share our vision.”

5. Today’s expertise is helping to build a low-carbon future

Geothermal initiatives will play a crucial role in our transformation to a net-zero company by 2050 and our employees are the backbone of the transition from a traditional energy company to a sustainable one. We are perfectly positioned to meet strong market growth in Europe, by drawing on our extensive expertise in geology, geoscience, drilling, subsurface, surface and advanced production technologies.

Geothermal energy was one of the earliest forms of energy known to mankind and remains an endless source of fascination in the classroom. Now, this clean, efficient and nearly inexhaustible resource is helping us build a healthier world for future generations.