LAUSR

Abstract The direct steam generator (DSG) solar power tower plant concept is receiving more attention due to its ability to provide superheated steam without any intermediate heat exchanger and heat transfer fluid. However, the literature on the time-dependent or quasi-static performance evaluation of these systems is limited. In this study, a thermoeconomic assessment of a DSG solar tower with a dual receiver mechanism integrated with a regenerative steam Rankine cycle is carried out. A quasi-static analysis of the system is provided to study the performance of a DSG solar power tower under different operating conditions, i.e. ambient temperature and solar irradiation. To do so, a flexible operation strategy is developed for the heliostat field at which the number of mirrors directed toward the evaporator and superheater is varied to maximize the output of the DSG system. The developed control strategy provides flexibility and improvement in the system’s performance in off-design conditions. Thermoeconomic analysis showed that a 50 MWe plant LCOE is 127.7 US$/MWh with an annual solar share of 42.3%. The plant LCOE is reduced to 114.6 US$/MWh by increasing the plant capacity to 150 MWe.