Off-design model of concentrating solar power plant with thermochemical energy storage based on calcium-looping

Abstract

Dispatchability is a key issue to increase the competitiveness of concentrating solar power plants. Thermochemical energy storage systems are a promising alternative to molten salt-based storage because of the higher energy storage density and the possibility of increasing the storage period. Among possible thermochemical systems, the Calcium-Looping process, based on the multicycle calcination-carbonation of CaCO3, is a main candidate to be integrated as energy storage system within a scenario of massive deployment of concentrating solar power plants. The present manuscript goes beyond previous works by developing an off-design model of the system that leads to a more accurate discussion on system size and plant efficiency. A capacity factor as high as 58% is calculated with lower mass of stored products than in commercial solar plants while the calculated solar-to-electric daily efficiency varies between 17.1% and 20.1%. Simulation results suggest an interesting attractive potential of the Calcium-Looping integration.