Geothermal Energy: Extreme Materials for Extreme Opportunities

At Sandvik, we are committed to using engineering and innovation for more sustainable business. We believe one of the many ways to pursue sustainability is through natural and renewable energy sources, such as geothermal energy.

Sustainable energy

Considered a clean energy source, geothermal heat can be extracted from below the Earth’s surface without burning fossil fuel, such as coal, gas, or oil. Found in certain geographical regions around the world and available year-round, this largely untapped renewable energy source offers a steady, predictable large-scale power generation.

According to the Office of Energy Efficiency & Renewable Energy, geothermal fields also produce only 1/6th of the carbon dioxide that a relatively clean natural-gas-fueled power plant produces and very little, if any, of the nitrous oxide or sulfur-bearing gases.

Demanding conditions

Production wells are drilled to various depths, but the trend in the industry is to go deeper for increased efficiency. In its most usual form, a well is drilled into an aquifer from which steam is used to power a Rankine turbine. These aquifers tend to be very saline (at saturation, the chloride content can reach 25%) creating an extremely corrosive environment. These corrosive conditions can be severe with high chloride and H2S contents, but low pH, which calls for the use of higher alloyed corrosion-resistant materials.

Newer designs for geothermal plants don’t use the aquifer water/steam to drive the turbine but transfer the heat to a cleaner working fluid via a heat exchanger which is exposed to the corrosive fluids in the process. This leads to higher demands on the materials used, such as the ability to resist higher temperatures and pressures.

Extreme materials

The success of geothermal energy depends on the ability of its components and the precision, performance, and durability behind the manufacturing process.

We have a wide range of alloys and heat exchanger tubing manufactured to embrace the heat and resist the corrosion seen in geothermal energy applications. Designed for extreme environments, our heat exchanger tubing provides:

  • High corrosion resistance
  • Lower life-cycle cost
  • High mechanical strength
  • Good weldability
  • And much more

Choosing the right material for equipment components can be difficult in complex applications that require more than a standard stainless steel. We can help you to select appropriate materials for your geothermal plant, and find solutions for the critical service conditions and applications.

Want to collaborate on reducing environmental impact with geothermal energy? Learn more about our heat exchanger tubing.

By Jennifer Svensson, Product Manager, Sandvik.