With capacity set to double by 2040, geothermal depends on stainless steel to overcome its biggest challenges
In the global race toward a cleaner, more secure energy future, geothermal energy is quietly gaining momentum. While solar panels and wind turbines often steal the spotlight, geothermal power – energy drawn from the Earth’s internal heat – is emerging as a reliable, low-emission, and increasingly scalable solution. And thanks to new drilling technologies, shifting geopolitical priorities, and smarter material choices like stainless steel, geothermal is no longer just a niche player – it’s becoming a cornerstone of the green transition.
With our combined decades of working with stainless steel and research and development, we’re now focused on identifying how advanced materials can support emerging technologies. Geothermal energy is one of the most promising frontiers today – and here’s why.
The Untapped Potential of Geothermal Energy
Geothermal energy harnesses the natural heat stored beneath the Earth’s surface. This heat can be used to generate electricity or provide direct heating for homes, buildings, and industrial processes.
There are three main types of geothermal power plants: dry steam plants, which use steam directly from underground to drive turbines; flash steam plants, which extract high pressure hot water which flashes into steam when the pressure drops; and binary cycle plants, which use geothermal water to heat a secondary liquid with a lower boiling point, which then in turn drives a turbine.
Binary cycle plants are particularly exciting because they can operate at lower temperatures, making geothermal viable in more locations than ever before.
According to the International Energy Agency (IEA), global geothermal capacity is expected to grow rapidly from the current level of 16 GW. Based on current policies, geothermal capacity will surpass 22 GW by 2030, increasing to more than 40GW by 2040. That’s a significant leap, driven by both technological innovation and the urgent need to decarbonize our energy systems.
What’s Driving the Momentum?
Several recent developments are accelerating the rise of geothermal.
Innovations in advanced drilling in the Oil & Gas sector are reducing the cost for new Geothermal wells, and new technologies like plasma drilling are set to revolutionize the industry. Also, Enhanced Geothermal Systems (EGS) create artificial reservoirs in hot dry rock, unlocking geothermal potential in regions previously considered unsuitable.
One of the most powerful accelerators of geothermal energy’s growth is the increasing support from governments and international institutions. Around the world, policymakers are recognizing geothermal as a strategic asset in the transition to clean, secure, and resilient energy systems.
In the European Union, the Net Zero Industry Act has identified geothermal energy as a key technology for achieving green transition goals. This legislation aims to streamline permitting processes, reduce administrative burdens, and channel funding toward clean energy infrastructure – including geothermal.
Combined, the governments of France, Germany and Netherlands plan to launch more than 200 geothermal heating plants up to 2030. Additionally, several projects are being planned and started across Europe.
In Europe, most geothermal plants are used for district heating as the brines – the fluids which are used to transfer heat – are not widely available above 100°C. The year 2023 was the second consecutive year for record-breaking sales of geothermal heat pumps, with an increase of 11.7% from 2022. However, temperatures as low as 80°C can be used to generate electricity by using the binary cycle, also called organic rankine cycle (ORC).
In the United States, bipartisan support for geothermal is growing. The Congressional Research Service highlights the potential for Enhanced Geothermal Systems (EGS) to supply up to 12% of US electricity demand by 2050. The U.S. Department of Energy has also launched a USD $84 million program to fund pilot demonstration projects for EGS as part of the Bipartisan Infrastructure Law. These projects aim to showcase EGS in various geological settings and help scale geothermal energy as a reliable, zero-carbon power source.
The geopolitical landscape, highlighted by the Ukraine war and Europe’s energy crisis, is driving European nations to focus on geothermal energy, as it offers a hedge against the volatility of global fuel markets. Unlike oil and gas, which are subject to geopolitical tensions and price shocks, geothermal energy is inherently local. Once a plant is built, it provides decades of stable, low-cost power, which is insulated from international market fluctuations.
Geothermal’s Role in the Green Transition
Unlike solar and wind, geothermal doesn’t depend on weather conditions – in fact, geothermal has a utilization rate of over 75%, compared to less than 30% for wind and less than 15% for solar. This makes it particularly valuable as a source of baseload electricity – energy that is available around the clock to meet consistent demand.
In terms of environmental impact, geothermal plants emit significantly fewer greenhouse gases than fossil fuel-based power generation. As calculated by the National Renewable Energy Laboratory, the median life cycle emissions for electricity generation is in line with other renewable energy sources, and significantly lower than fossil fuel electricity generation:
- Coal: 1,001 gCO₂e/kWh
- Natural Gas: 486 gCO₂e/kWh
- Solar PV: 43 gCO₂e/kWh
- Geothermal: 37 gCO₂e/kWh
- Wind: 13 gCO₂e/kWh
Beyond its environmental benefits, geothermal energy also contributes to energy security. Because it is locally sourced and not reliant on imported fuels, it reduces exposure to global energy market volatility and geopolitical risks. Once a geothermal plant is operational, it can produce electricity for decades with minimal maintenance, offering long-term cost stability and a compact physical footprint compared to other energy facilities.
There are also geothermal fields – for example, along the Salton Sea and the Upper Rhine Graben – that can contribute to energy storage. The brines from these fields have relatively high concentrations of lithium, which can be extracted and used in the production of batteries.
The Stainless Steel Advantage
So where does stainless steel come in?
Geothermal environments are harsh. The fluids extracted from underground often contain high levels of chlorides, hydrogen sulfide, and other corrosive elements. This makes material selection critical for safety, cost-efficiency and longevity.
When compared to carbon steel, not only does stainless steel present advantages regarding corrosion resistance, but also it is not prone to the precipitation of heavy metal ions, the so-called heavy metal scaling, common phenomenon for example in the Rotliegend formations in the Netherlands and in north Germany. Reason for that is the stainless steel’s passive layer, which blocks the electron transfer between steel and metal ions, thus avoiding their deposition.
Key applications of stainless steel in geothermal systems include:
- Heat Exchangers: Transfer heat efficiently from geothermal brine to a secondary fluid in binary cycle plants. Stainless steel grades like Duplex 2205 resist corrosion and perform well thermally.
- Piping and Tubing: For transporting geothermal fluids, stainless steel provides durability and low maintenance. Solutions as mechanically lined tubes (MLT) can become a cost efficient solution.
- Well Casings: Protect deep geothermal wells from collapse and contamination. Stainless steel is essential in high-chloride environments and withstands intense thermal and mechanical stress.
- Storage Tanks and Valves: Store chemicals and handle high-pressure, high-temperature fluids. The durability of stainless steel reduces the risk of leaks and failures. In general, it is also common that Duplex stainless grades actually can reduce the weight and initial cost for a Storage Tank, in comparison to coated carbon steel.
- Pressures vessels or reactors for lithium extraction: temperature and pressure are necessary for concentrating lithium chloride and converting it into lithium carbonate, requiring usage of alloys with high corrosion resistance, such as 2507 or Sanicro 35.
Stainless steel is not just a material choice; it is a commitment to the future of geothermal energy. Investing in the right materials today ensures that we harness the earth's energy safely and efficiently for generations to come. The journey towards a sustainable energy future is not merely about adopting new technologies, but also about making smarter, more resilient choices in the materials we trust to build that future.