Combined linear Fresnel solar Rankine cycle with multi-effect desalination (MED) process: effect of solar DNI level on the electricity and water production costs

In the present study, the direct steam generated from a linear Fresnel solar field was considered to be used as the working fluid of a Rankine cycle. Four regions located in North and South hemispheres and with different annual direct normal irradiance levels, ranging from 1,950 to 2,750 kWh/m(2),SRC/MED/LF were selected to investigate the effect of solar radiation on the performance of a linear Fresnel/solar Rankine cycle (LF/SRC). The condenser of the LF/SRC plant was considered to be replaced by a multi-effect desalination (MED) unit. Different thermal storage capacities were considered for the LF/SRC plant with the electricity generation and water production rates of 85 MW and 80,000 m(3)/d, respectively. Not only the required solar field area, thermal energy storage (TES) capacity, solar multiple (SM) were investigated but also the water and electricity costs of the plant. A sensitivity analysis was performed on solar field cost, TES system cost and fuel cost in order to determine the sensitivity of the electricity and water unit of costs to each of the mentioned cost parameters. In order to determine the effect of plant size on the water and electricity unit of costs, the calculations were made for the SRC/MED/LF plant with the larger scales.