A simplified calculation method for the evaluation of the performance of a hybrid solar plant with linear parabolic collectors and Joule-Brayton air cycle

Abstract

A calculation method for the evaluation of the performance of a 50 MW hybrid solar plant with linear air collectors and an open Joule-Brayton air cycle, equipped with an interrefrigerated compressor, a regenerator and a natural gas combustor has been developed. If the plant is operated each day between sunrise and sunset for an entire year in conditions close to nominal ones, the net electricity produced in one year is 244,000 MWh, the fuel consumption is 34,575 tons of natural gas, the annual average efficiency of solar collectors is 49.8%, the average thermodynamic efficiency of power block is 42.1%, the average conversion efficiency of solar energy to electricity is 20.9%. The saving of fossil fuel due to the employment of solar energy in the hybrid plant is 22%, the cost of electricity produced results to be 8.3 cents$/kWh. This value is competitive with that of other plants using renewable energy.