Solar combined cycle with high-temperature thermochemical energy storage

The present work proposes integrating a high-temperature thermochemical energy storage cycle to boost the solar contribution in solar combined cycles. The main feature of the plant is the possibility of storing solar energy at a very high temperature and releasing it on demand to drive the combined cycle in the absence of solar radiation. Based on the reversible calcination-carbonation of CaCO3/CaO, the Calcium-looping process is proposed since it allows power production above 900 degrees C by using cheap, non-toxic and widely available raw materials (i.e. limestone or dolomite). Based on an air-open and a CO2-closed combined cycle, two potential configurations are modelled and analysed, including designing a 360 degrees solar field with a 200-meter tower. The novel solar combined cycle analyzed in the present work enhances the annual solar share above 50%, whilst the current state-of-the-art technology is below 15%. From actual solar irradiation data and clustering analysis, results show overall plant efficiencies over 45% (considering off-design performance) with a very high dispatchability, which justifies the interest in further developing this novel cycle.

Automated summary

This research proposes integrating a high-temperature thermochemical energy storage cycle into solar combined cycles to enhance the solar contribution. The novel solar combined cycle analyzed in this work significantly increases the annual solar share and demonstrates high plant efficiencies and dispatchability.