Solar energy has the potential to reduce power generation dependence on fossil fuels. However, the periodic nature and uncertainty of the solar insolation call for the deployment of energy storage. Thermal chemical storage (TCES), which stores and releases energy by breaking and reforming chemical bonds, has high energy density and the potential for long storage period. To this end, we perform system level studies for TCES systems in concentrating solar power (CSP) plants. Specifically, we develop general optimization-based methods for the synthesis and evaluation of various reaction candidates and technology alternatives (see Figure 1).