Tue, 04 October, 2022
Geothermal energy storage systems use phase change materials (PCM) to store heat at an almost constant temperature level through a phase transition and these systems are often referred to as PCM modules.
The most ubiquitous PCM, H2O, has been used to store winter cold to cool buildings in summer since the Achaemenid Empire. However, the operating range of this ubiquitous fluid is limited. To provide flexibility, industries use a wide variety of PCMs such as polyethylene, paraffin, and inorganic eutectic mixtures like ‘chameleons’ depending on the nature of the geofluid demand. These systems offer an innovative approach to storing the sensible heat of the brine in the latent heat of melting of the PCM. Therefore, integration of PCM thermal energy storage units are expected to give geothermal power plants the ability to store heat and then turn heat into power via an existing steam unit to meet with grid demands in peak hours.
TWI has already carried out an exhaustive literature search and review on material selection and analysis to identify the optimum phase change materials and suitable metal-metal alloy combination. Based on the consortium expertise and experience, TWI has performed initial experiments involving two PCMs and a series of different metal-metal alloys and assessed their corrosion performance with the aim to increase the flexibility of geothermal plant facilities in overcoming the dynamic peak loads. The GeoSmart consortium, comprising of geothermal operators, SMEs, equipment suppliers, Universities, and research and technology organisations, is currently investigating the efficacy of the PCM thermal storage module and comparing them with different storage options such as steam accumulator, sensible heat storage (hot water).
To find out more about the work on PCM, join our expert, Dr Shiladitya Paul on 18 October for his talk on, ‘Materials selection for Adipic Acid-based PCM thermal storage system’ at the European Geothermal Congress, in Berlin from 17-21 October 2022.
About EGC
The European Geothermal Congress is Europe’s largest event of its type, drawing stakeholders from across the continent and from further afield. The diverse event is created by the sector for the sector and includes policy and scientific sessions, an exhibition, training courses, science bars, site visits, and networking events to promote the geothermal sector in Europe and beyond.
Organised every three years, the EGC provides a unique opportunity for stakeholders from all parts of the sector, whether academic, industrial, financial, policy-making, or societal, to come together, learn, and find new ways to progress.
The GeoSmart project has received funding from the European Union's Horizon 2020 research and innovation programme grant agreement 818576