Thermo-economic and environmental assessment of a hybrid solar power plant with a packed-bed thermal storage and a supercritical orc power block

Abstract

In this paper, an optimization-oriented model of a hybrid solar power plant is proposed. The facility is composed of a parabolic trough solar field, a packed bed thermal storage, a fired heater and a supercritical ORC power block. In a first step, all the components of the power plant are sized. In a second step, its operation is simulated over a typical year using irradiance data as input which allows to assess the Levelized Cost of Electricity (LCOE) and the amount of CO2 emitted per kWh produced. A new analytical model developed by the authors is used to simulate the operation of the heat storage and permits to reduce considerably the computation time. Therefore, the model is suitable to be integrated in stochastic optimization algorithms. Finally, the effects of the solar field size and the storage tank on the LCOE and CO2 emission are investigated and it has been found that the shape factor of the packed bed storage (the ratio between the hight and the diameter) is a very important parameter that affects the impact of the storage integration on the LCOE and CO2 emission levels.