Geothermal energy makes an important contribution to climate-friendly electricity and heat generation worldwide. In order to provide heat for buildings or generate electricity, geothermal energy extracts heat from the ground. Geothermal energy is base-load capable and independent of wind, tides and sun. (IRENA and IGA 2023; Stober and Bucher 2020)

A key operational challenge in the use of geothermal energy is often limited flow rates. These reduce heat transfer, which reduces the efficiency of geothermal plants (image above: German Geothermal Association 2016). A common cause of limited flow rates are deposits (scales) of minerals and microparticles (right image: German Geothermal Energy Association 2022) and corrosion in the pipes (bottom image: German Geothermal Energy Association 2016) and system components. Complex cleaning and maintenance work is required to prevent a drop in the system’s performance, which results in high costs. (van Pull-Verboom 2020; Stober and Bucher 2020)

In order to improve the performance of geothermal plants, increase the service life of the plants and ensure maximum energy production when required, the PERFORM II project aims to develop new methods and technologies that enable an increase in energy production. The technologies should be efficient and cost-effective and offer environmentally friendly improvements and alternatives to the current state of the art. (Regenspurg 2022; van Pull-Verboom 2020).

The PERFORM II project aims to filter the cations Cu2+ and Pb2+ from the thermal water and thus prevent the accumulation of radionuclides as well as deposits and corrosion in the plant. Zeolites and chitosan are used for this purpose. In the course of the project, a filter system will be designed and assembled in cooperation with the Fraunhofer IEG. After construction and a test phase in the laboratory, the filter system will be tested at various geothermal plants in Germany and the Netherlands. (van Pull-Verboom 2020)