Experimental characterisation of a novel phase change material heat storage unit for state-of-charge estimation

Energy storage methods will be a critical part of the future energy supply system, as demand is increased by electrification of domestic heat and take-up of renewable generation increases the variability of supply. Domestic storage units are likely to be key to this transition, and this paper will present investigations into a unit for storage of domestic heat. A phase change material (PCM) heat storage unit has been developed that has the potential to provide effective heat storage facility in a domestic capacity. Effective control and use of the storage units is dependent on accurate state-of-charge (SoC) estimation, tools for which are being developed and supported by data presented in this paper. A novel test bed has been developed in order to acquire data for this purpose. The rig is situated in a temperature-controlled chamber which enables charge and discharge tests at a range of ambient temperatures. Automated control of the rig is also available, which allows for repeatable tests to be carried out to gather data for model development.