Latent Heat Based High Temperature Solar Thermal Energy Storage for Power Generation

The design of a phase change material based high temperature solar thermal energy storage device is presented. Said unit will be used as an energy reserve for a 1 kWe domestic CCHP system using a Stirling engine to produce electric power. The thermal energy storage is conducted by means of the exploitation of the latent heat of fusion of the material contained inside the tank. This method was chosen because a great energy density is obtained and, at the same time, it is possible to extract the stored energy with very small variations on the temperature, which is a favorable feature for its intended purpose. The selection of the phase change material is discussed and the design of the different components of the proposed storage model is described. It is analyzed, as well, the insulating solution applied that minimizes heat losses. Finally, a comparison between experimental results of the tests performed on the first built to scale prototype and the data obtained from computer simulations is shown.