The critical role of valves in geothermal energy

The world around us is looking for cleaner energy on an industrial scale to responsibly meet growing consumption demands. The need for renewable energy sources is rising at a rapid pace. Geothermal energy is continuously produced inside the earth. In addition to thermal energy, in some areas the geothermal fluid may contain lithium, which is vital for batteries used to power the energy transition. We just need to harness that energy, and the lithium, in a sustainable way. Reliable, high-performance valves play a significant role in producing renewable energy from geothermal sources.

Industrial processes for cleaner energy

Geothermal power plants harness the Earth's internal heat by extracting geothermal fluids, typically in the form of hot brine or steam, which are then used to drive turbines connected to generators, producing electricity. If the lithium content in the brine is big enough, one of the Direct Lithium Extraction (DLE) methods can be applied to capture this additional benefit from geothermal recourses.  

Hydrothermal geothermal power plants where the fluid is extracted directly from the underground are most common. Theses power plants can work as one of three types; Flash steam, dry steam or binary cycle. Binary cycle power plants operate using a secondary working fluid with a low boiling point - commonly a hydrocarbon such as Pentane. This fluid is heated by the geothermal brine, causing it to vaporize and drive an Organic Rankine Cycle (ORC) turbine to generate electricity.

There are also so-called Enhanced (EGS) and advanced (AGS) systems applied. Also, the Superhot Rock System (SHR) and the Supercritical Geothermal Technology (SCGT) are still notably in the R&D stage and yet to be commercially applied.

“As the global demand for lithium continues to grow, some countries are exploring possible synergies with geothermal where the brines often contain dissolved lithium.”

Serving a global demand for geothermal

Currently, Indonesia has the highest annual geothermal production while the US still has the highest amount of installed capacity, even if geothermal only accounts for a fraction of the energy used nationally. Countries such as Kenya, Iceland, New Zealand and El Salvador are already heavily dependent on geothermal for a large part of their energy.

Did you know that we have been involved in many geothermal power plant projects around the world? Our experts have worked with customers from Iceland to Turkey, Kenya to New Zealand, and from Indonesia and the Philippines to Latin America and the United States. We offer also valve solutions for the new geothermal technologies of EGS, AGS, SHR and SCGT.

As the global demand for lithium, an essential component in batteries, continues to grow, countries such as the US, Germany and Chile are exploring possible synergies with geothermal where the brines often contain dissolved lithium. Pilot projects for the extraction of lithium from brines are already in motion. By using advanced direct lithium extraction (DLE) technologies, it's already possible to recover lithium without significantly disrupting the geothermal process.

Efficiency performance in harsh conditions

Brine and steam temperatures in geothermal systems range from 100°C to 370°C and often contain silica, lime, sulfur, and other minerals. Advances in geothermal technology now allow electricity generation even from brine at 100°C or lower. Valves are critical in this process, as they must minimize pressure loss while withstanding these impurities. Steam up to 370°C - and in future SCGT and SHR systems, even hotter - adds further challenges for both valves and the overall system. Poor valve selection or maintenance can cause energy losses, inefficiency, or serious damage, especially to separators and turbine blades.

Geothermal plant valves also face harsh conditions, including high pressure, flashing, and silica scaling, while still ensuring safe, efficient flow control. Pressure and temperature fluctuations demand high valve performance. A major issue is silica scaling: deposits inside valves lead to leakage, which accelerates scaling and can ultimately cause complete valve failure.

Another challenge for the geothermal business can be project duration: the traditional deployment of geothermal power plants can take years, from project start to having power online. These projects require large investments and, in these kinds of huge projects, reliable and experienced partners are often welcome.

Safe, reliable, and energy efficient

With reliable, high-quality valves, geothermal power plants can produce renewable energy efficiently and safely at a low cost and low environmental impact. The availability of the geothermal plant is crucial, which is why durable valves requiring minimal maintenance are preferred. Our proven valve solutions are an ideal fit for the geothermal industry where the natural variation of fluid conditions can be very demanding.

Valmet has the industry’s widest product scope with an extensive pressure rating for the wellhead-steam lines to the main steam distribution system within a geothermal plant. Customers can rely on us, as we have notable experience in sizing and selecting the right valves for their geothermal service. In addition, if maintenance or expert help is needed, we also support our clients with comprehensive life-cycle services.

One service that has been well received is our Resident engineer service. This is when we assign a dedicated local service technician to the factory. In a case in Turkey for example, a geothermal power production facility contacted us to provide immediate service support to help solve their valve problems and minimize production losses. With several on-site visits per month, the geothermal facility reduced production losses and was ultimately able to define and prevent potential future problems.

The right valves for geothermal plants

Neles™ and Jamesbury™ valve solutions ensure efficient and reliable operation in geothermal power plants. The heavy-duty Neles™ Finetrol™ eccentric rotary plug valve is ideal for separator level control (LCV). Neles™ metal-seated butterfly valves have demonstrated long, maintenance-free service in geothermal plants worldwide. Their eccentric plug or triple eccentric disc design, combined with hard-coated metal seats, allows continuous operation even under heavy scaling.

On the turbine side, particularly in binary cycle (ORC) plants, customers rely on high-performance, soft-seated Jamesbury™ Wafer-Sphere™ valves. These examples highlight how valves are critical in geothermal energy. Our broad range of control valves, backed by industry experience, supports safety and environmental compliance.

Our technical expertise also offers solutions for the requirements of new geothermal technologies such as the SHR and SCGT. As an established name in mining, metals and steel processing around the world Valmet also offers wide portfolio of flow control solutions for lithium production from brine sources.

Bright future for clean energy

As the technologies surrounding geothermal energy continue to develop, we are hopeful for a future where this clean source of energy plays an increasingly major role in society. We are equipped and excited to supply reliable, high-performance control valves for all new geothermal projects. For more detailed information, contact our experts at any time.