Thermal energy storage is a key feature of concentrating solar power facilities. The basic idea is to store a fraction of the thermal energy generated by the solar system in a specific, suitable material. This stored energy can then be used both for extending process operation (electricity generation cycle, thermo-chemical reaction, etc..) beyond the hours of sunlight and keeping the parameters of the heat supply to such a process stable at all times, avoiding problems due to the transient nature of solar irradiance. However there is not a unique storage system that can be used for all different CSP concepts (troughs, towers, dishes) but the storage design depend strongly on the heat transfer medium, temperature level and other parameters.
Different storage concepts have been developed and tested in different research infrastructure facilities in Europe.
Test procedures and evaluation methodology between the different research infrastructure facilities are inconsistent, uncoordinated and sometimes contradictory. As an example, for Phase Change Material (PCM) storage, being extremely favourable if water/steam is used as heat transfer medium, there is no convincing method available to determine accurately the charging/discharging status of a PCM storage.
The main outcome of this WP15 (JRD) will be a joint and systematic approach, aiming to overcome fragmented status and to provide a scientifically sound methodology to test and to evaluate different types of thermal energy storage systems and materials in all European CSP infrastructure installations.
- Methodology to characterize various types of storage systems (350 kB).
- Definition of a standardised procedure (including a Handbook) for the testing of all types of storage (1.2 MB).
- Methodoloy and standardised procedure (including a Handbook) to characterize storage materials (4.9MB).
- New measurement systems which is able to determine the charging/discharging status of latent heat storage materials (3 MB).