Optimal Indirect Integration of Steam Rankine Cycles in Concentrated Solar Power Coupled with Thermochemical Storage

Energy Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, Torino, 10129, Italy

^* Corresponding author: umberto.tesio@polito.it

Abstract

Storing energy in thermo-chemical form is a promising alternative for renewable energy sources and one of the fields that could exploit its advantages is constituted by Concentrated Solar Power (CSP). High efficiencies, high energy densities, long-term storage and dispatchability in power generation could be tackled with the employment of a Calcium-Looping in a central tower CSP plant. Although Brayton cycles based on sCO2 and He probably represent the most efficient option, it can be interesting to investigate the integration of Steam Rankine cycles because of the lower costs and the higher stage of development that characterize this technology. The present work has the purposes of studying this kind of integration and analyze the system in both energy and economic terms. To perform a comprehensive investigation, the power block layout and its thermal feeding strategy are included in the analysis and optimized. In addition, a multi-objective optimization is performed to evaluate possible compromises between the two most important aspects related to the entire power plant.