Dynamic modeling and simulation of a concentrating solar power plant integrated with a thermochemical energy storage system

This paper presents the dynamic modeling & simulation of a concentrating solar power (CSP) plant integrated with a thermochemical energy storage (TCES) system. The TCES material used is calcium hydroxide and the power cycle studied is a Rankine cycle driven by the CSP. Firstly, dynamics models of components written in Modelica language have been selected, developed, parametrized, connected and regulated to create the CSP plant with different TCES integration concepts. Then simulations were performed to determine and compare the energy efficiency, water consumption and energy production/consumption of three integrations concepts for two typical days (summer and winter) and for a basic continuous production mode. After that, a feasibility study has been performed to test a peak production scenario of the CSP plant. The results showed that the TCES integration could increase the overall efficiency of the CSP plant by more than 10%. The Turbine integration concept has the best global efficiency (31.39% for summer; 31.96% for winter). The global electricity consumption of a CSP plant with TCES represents about 12% of its total energy production for a summer day and 3% for a winter day. An increased nominal power by a factor of 10 could be reached for the peak production mode within one hour using the Turbine integration concept, but with a lower global efficiency (17.89%).