The EU-funded REFLECT project aims at preventing problems related to geothermal fluid chemistry which are currently a key problem for the efficiency of most geothermal operations. The project team recently met virtually to evaluate its progress within the first twelve months.
The efficiency of geothermal utilisation depends on the behaviour of fluids that transfer heat between the geosphere and the engineered components of a power plant. REFLECT aims to prevent problems related to fluid chemistry rather than treat them. The physical and chemical fluid properties are often poorly defined, as in situ sampling and measurements at extreme conditions are difficult to date. Therefore, large uncertainties in current model predictions prevail, which REFLECT aims to tackle by collecting new, high-quality data in critical areas.
The Covid-19 pandemic has caused delays as it affects both the sampling campaigns and the laboratory work. Nevertheless, the team could collect and evaluate existing data, and also advance the modelling. So far, sampling campaigns took place in Tuzla and Aydin in Turkey, Bad Blumau in Austria, Insheim in Germany, Krafla and Theistareykir in North Iceland, and Bouillante in Guadeloupe. Further campaigns are planned for Neustadt-Glewe and Heemskerk as soon as Covid-19 related restrictions will be lifted. First analyses of the geothermal fluids have been completed and revealed interesting microbial spores and fungi in the geothermal waters from Insheim and Bad Blumau. The modification of experimental set-ups for investigations on fluid physics, polymerisation, silica precipitation and degassing kinetics is also well underway. In autumn 2020, the team has reached one of its milestones, the ‘Construction and testing of the high p, T equipment for scale experiments’. For this purpose, the Institute for Energy Technology (IFE) worked on the development and testing of experimental setups and methods to determine mineral solubility limits and dissolution kinetics in highly saline brines at temperatures up to 200 °C.
By the end of 2021, a beta version of the European Geothermal Fluid Atlas will be launched. This online database will provide information on fluid properties all across Europe. The atlas will cover geographical and physical data of wells, fluid sample, rock sample as well as reservoir data. It will be freely available to the public, providing relevant data especially for geothermal operators. The team working on predictive models aims at improving existing numerical models in order to better predict geochemical processes and optimise the fluid flow behaviour in the geothermal loop. The modelling will allow to provide recommendations on how to best operate geothermal systems for a sustainable use.
The REFLECT approach aims thus at improving the operational efficiency, project economics and viability as well as the environmental footprint of geothermal operations. Ultimately, REFLECT intends to contribute to the increase of the number of economically viable geothermal sites, broadening thus the share of geothermal energy within the European energy market.
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