Theoretical analysis of a solar-powered multi-effect distillation integrated with concentrating photovoltaic/thermal system

A novel concentrated photovoltaic/thermal-multiple effect distillation system is proposed to simultaneously provide electricity, heating and freshwater for satisfying essential demands from isolated islands. Theoretical analysis under nominal condition is evaluated from perspective of energy and exergy and results indicate that electricity and heating are 353.2 and 432.9 kW with related energic and exergic efficiency of 0.2966 and 0.3635, 0.3177 and 0.0064. Produced freshwater is calculated as 0.7107 kg/s with gain output ratio of 6.59. Exergy destruction analysis exhibits detailed scenario of exergy consumption and solar collector field obtains the largest destroyed exergy, followed orderly by multiple effect distillation, heating unit and preheater. Parametric and sensitive analyses are performed to illustrate effects of parameters on system performance. Results indicate operating parameters exert remarkable impact on system efficiency. Efficiency of electricity is most sensitive to photovoltaic cell temperature, while that of heating and freshwater are most sensitive to coolant fluid temperature in comparison to the rest parameters. Primary energy and exergy saving ratio are conducted and results indicate proposed system is superior over individual systems with the same amount of electricity, heating and freshwater. In conclusion, this built system achieves a rational and efficient strategy to the comprehensive utilization of solar energy.