Techno-economic optimization of Concentrated Solar Power plants with thermocline thermal energy storage and integrated steam generator

The utilization of molten salts as the Heat Transfer Fluid (HTF) in Concentrated Solar Power (CSP) allows to increase the maximum operational temperature of parabolic trough power plants, with a substantial gain in the power cycle efficiency. ENEA has recently tested a way to further ameliorate this concept by introducing a single-tank configuration of the storage system with an integrated steam generator, which can dramatically reduce the total investment cost and simplify the power plant layout. In this paper we propose to couple this system to a waste-heat recovery unit for the cogeneration of power, heating and cooling, which has the potential to extend the range of applications of CSP plants to small-size systems and to regions with a moderate solar resource. In this paper, a techno-economic analysis is implemented to investigate the feasibility of this innovative technological pathway, to determine the optimal design of a representative 1 MWe plant located in Rome and to analyze its performances.Results reveal that the heat market brings a 28 % reduction of the Levelized Electricity Cost, allowing to reach the competitive value of 230.25 $/MWh. This is remarkably lower than the Feed-In-Tariff (FIT) of the Italian incentive scheme for CSP and comparable to the specific cost of larger plants despite an investment cost limited to 14.56 M$.