Pilot testing of water utilization for integrated solar energy storage and power production using linear Fresnel collector and organic Rankine cycle

Abstract

This work presents a new method of utilizing water as thermal energy storage to improve the capacity factor of integrated linear Fresnel collector – organic Rankine cycle (LFC-ORC). A new process flow diagram has been proposed to manage overnight operation of the ORC relying on thermal energy storage in water. Pilot testing of 10 kW capacity of LFC-ORC process under arid and desert conditions of Arabian Gulf operating conditions (Qatar) is also reported. A thermodynamic analysis has been performed based experimental evaluation and process simulation of the LFC-ORC production and efficiency. The LFC-ORC operations at storage temperatures of 170 °C showed peak electricity production of 6.76 kW (38 W/m2 aperture area of LFC) whereas 1st law, and 2nd law efficiencies were 6 % and 19 %, respectively. An operational strategy is proposed to generate 5 kW over a period of about 12 h using 10 m3 storage capacity. The developed process simulation program showed that two LFC systems, each 176 m2 aperture area, equipped with three storage tanks each 10 m3, must be installed to generate 5 kW electricity for 24 h. The proposed system can be upscaled to any size as per end-user needs. The new system design would be subjected to further optimization and feasibility to cope with the development of the ORC and LFC efficiency in the future.