Techno-economic evaluation of solar-nuclear hybrid system for isolated grid

Abstract A solar-nuclear hybrid system that combines Concentrating Solar Power (CSP) and nuclear power was suggested previously to meet the electricity demands for remote microgrids. The hybrid system combines CSP, Thermal Energy Storage (TES) and a Micro Modular Reactor (MMR). A Supercritical Carbon dioxide (sCO2) power system is used for power generation system. CSP, which has relatively high efficiency, no refueling, low operation and installation costs, is suitable as an energy source for the microgrid. However, since it is challenging to meet 100% electricity demand with a standalone CSP system due to excessive energy storage system and large land area requirement, a hybrid system is proposed by adding a nuclear system to resolve this issue. The hybrid system showed a higher capacity factor than the standalone CSP system while reducing the required energy storage. However, the TES capacity was still excessive to meet 100% of the electricity demand in the previous study to overcome seasonal variation. Therefore, in this study, the hybrid system is re-designed by optimizing solar to nuclear ratio while tracing change in the Levelized Cost Of Electricity (LCOE) of the system. A sensitivity analysis is performed with respect to the five variables; nuclear to solar heat ratio, direct normal irradiation, peak-to-average electricity demand ratio, nuclear island cost, discount rate affecting LCOE. As a result of economic evaluation, it is confirmed that the hybrid system is cost competitive to the standalone CSP system. This study showed that the nuclear-CSP hybrid system can be utilized as a power source with a high potential for isolated microgrid.