Modeling of a linear Fresnel direct steam generation solar thermal power plant with sensible-latent hybrid thermal energy storage: A case study for Northeastern Brazil

Abstract

This study aims to model a linear Fresnel reflector concentrated solar power plant to assess its potential for electricity generation in Northeastern Brazil, where the annual direct normal irradiation exceeds 2,000 kWh m-². Time-series simulations were performed using EBSILON Professional. The modeled plant consists of three subsystems: (a) a solar field, where superheated vapor is generated at 550°C and 107 bar, (b) a sensible-latent hybrid thermal energy storage with a capacity of six hours, and (c) a 30 MWe power block. From annual plant simulation, the profiles for electricity dispatch, capacity factor, and solar-to-electric efficiency for one year are obtained. The results showed an even distribution of the monthly power output, although the generation is higher during the dry season (April to September) than the wet season (October to March). The opposite occurs to thermal energy storage: the stored energy is more relevant during the dry period. Thus, the satisfactory performance of the proposed storage system and the solar-to-electric efficiencies obtained suggest direct steam generation and sensible-latent storage integration could play an important role in enabling concentrated solar power plants using linear Fresnel reflectors to be competitive in the Brazilian energy market.