Spanish-based plastics technology centre AIMPLAS is one of the ten participants in a European project led by the Universitat Politècnica de València, aimed at developing new components for geothermal systems offering high thermal-conductivity properties.
Geothermal heating is the direct use of the heat stored inside the earth for as an energy source for heating and air conditioning applications. With the current drive towards transitioning to more sustainable, renewable energy sources, harnessing the heat deep in the earth is one of the options attracting increasing interest.
In these closed-loop systems, an underground geothermal probe, consisting of a polyethylene tube through which a heat-transfer fluid flows, is used to capture the heat. Some systems are configured horizontally; most, however, are systems with vertical borehole heat exchangers. Vertical installations require boreholes to be drilled for the probes to be installed. Drilling the holes, which are around 100 metres deep and filled with specific filler, is the most expensive part of the system.
Using the new highly temperature-conducting components which are being developed within the scope of the GEOCOND project, will improve the efficiency of these geothermal systems, by reducing the drilling depth needed by up to 20%, advanced grouting additives and concepts, advanced phase change materials and system-wide simulation and optimisation. Together, these could shave up to 25% of the cost of the installation.
The project, launched a year and a half ago, will run for three-and-a-half-years and has pnow produced its first results. Different formulations with high thermal conductivity have been developed, and test components have been extruded at pilot scale. The next step will be industrial production. This will take place at two of the other participants in the project, Silma and Caudal Extruline Systems.