Thermal energy storage in CSP plants. Greater efficiency at lower cost and new concepts


Compared to other renewable energy sources, the main advantage of concentrated solar power (CSP) plants is their easy integration into thermal energy storage (TES) systems. This is undoubtedly a key aspect for this type of plants as they allow the production of electricity to be adapted to demand as well as bringing stability to the grid.

Today, two-tank molten salt storage systems are the only commercially-available technology. The system consists of two tanks, one storing the hot fluid and the other containing the cold fluid. In this system, these fluids cannot be mixed thereby giving the system the maximum energy availability (exergy). The molten salt from the cold tank is heated by the energy harnessed from the solar field and then stored in the hot tank.

If there is insufficient solar radiation to generate electricity, the energy stored in the hot tank is recovered for steam generation in the power block. Once this energy is transferred, the molten salt flows back into the cold tank.

Carlos D. Perez-Segarra (Professor), Ivette Rodriguez (Associate Professor), Santiago Torras (Researcher), Pedro Galione (Researcher), Ignacio González (Researcher), Joaquim Rigola (Associate Professor), Assensi Oliva (Professor)
Heat and Mass Transfer Technological Center (CTTC), Universitat Politècnica de Catalunya

Article published in: FuturENERGY March 2015