Thermo-economic analysis of steam accumulation and solid thermal energy storage in direct steam generation concentrated solar power plants

In direct steam generation (DSG) concentrated solar power (CSP) plants, a common thermal energy storage (TES) option relies on accumulation. This conventional is constrained by temperature and pressure limits, delivers saturated or slightly superheated at reduced during discharge, which undesirable for part-load turbine operation. However, accumulation can be integrated with sensible-heat in concrete to provide higher-temperature higher pressure. this paper, (existing) an concrete-steam TES (extended) are described analysed, their thermo-economic performance compared taking the 50-MW Khi Solar One DSG CSP plant South Africa as case study. The results show that extended five 10-m long, square cross-section blocks, each 3600 equally spaced tubes, provides additional capacity of 177 MWh existing configuration result utilising most available receivers. Moreover, 58 % more electricity 13 enhancement efficiency discharging mode. With estimated investment $4.2M, levelised costs are, respectively, 29 6 lower than those obtained option. option, projected net present value increases 73 %, from $41M $71M, average price 280 $/MWh.