A zero-carbon integrated energy system energized by CSP + PV: A real case of isolated grid

Abstract

The integration of concentrated solar power (CSP) system and photovoltaic (PV) can extend the dispatchability of solar energy while contributing to carbon neutrality goals. This paper investigates a real case of zero-carbon integrated energy system energized entirely by solar energy, incorporating CSP, PV, thermal energy storage (TES), and batteries. The system utilizes an extraction condensing steam turbine with flexible heat-to-power ratio as CSP power block, complemented by a segregated steam generation system (S-SGS) enabling direct thermal production from TES, to reduce coupling between electrical and thermal outputs. Based on the case, comprehensive techno-economic analysis through annual hourly production simulation demonstrates that the hybrid system achieves continuous 24-hour operation and meets a 91.17% annual production rate with a levelized cost of energy (LCOE) of 0.121 USD/kWh, representing 2.4% and 4 % reduction compared to the system operating without S-SGS and in separate heat and power production modes, respectively. For reliability enhancement, our analysis reveals that a thermal storage duration to solar multiple ratio of 5.5–5.8 enables the most economically efficient reliability improvements. This optimization allows the system to achieve a 99% annual production rate at an LCOE of 0.172 USD/kWh. However, attaining reliability levels comparable to conventional urban power grids would necessitate prohibitively expensive investments despite significant technological advances.