Techno-economic Analysis of Hybrid Supercritical CO2 Based Molten Salt Tower CSP-PV

The present work performs a techno-economic analysis of a hybrid CSP - PV plant composed of a molten salt tower CSP running a supercritical CO2 power unit and a PV field. The two plants are connected in parallel, behind the meter. The PV unit produces power during daylight. The CSP plant stores thermal energy during the day to enable stable production during cloudy periods and enlarges the plant capacity factor while producing during the night. The plant performances have been evaluated in terms of capacity factor, thermal energy storage utilization factor, capital expenditure, and Levelised Cost of Electricity. The influence of plant solar multiple, storage size, supercritical CO2 nominal size, PV relative nominal size, receiver thermal efficiency, CO2 power unit, and PV cost assumptions has been assessed through different sensitivity analyses. The results show that it is worth hybridizing the system, indeed the PV unit can provide low-cost renewable power during the day, while the CSP unit can provide a cheap storage technology. Plant configurations leading to a Levelised Cost of Electricity lower than 70 S/MWh(e) can be identified already at relatively low nominal power size, 15 MWe. The receiver thermal efficiency is shown to be a highly important assumption, highlighting the need for further component development.