Energy and exergy analyses and electricity generation of PV-T combined with a solar collector for varying mass flow rate and ambient temperature

In this study, energy, exergy and electricity generation of a system that comprises a photovoltaic thermal panel (PV-T), evacuated tube solar collectors (ETSCs) and an organic Rankine cycle (ORC), solar pool a water storage tank are investigated. PV-T and ETSCs have an area of 30.24 m(2). The PV-T increases the temperature of the water entering the ETSCs by preheating it. Thus, the preheated water, whose temperature is further raised by the ETSC, is pumped into the ORC that contains R134 as a working fluid to generate electricity. While the electricity generated by PV-T and ORC is supplied to the home, the produced hot water is collected in an insulated tank for domestic use. The system is assumed to be operated under constant solar radiance of 500 W/m(2) and ambient temperature conditions ranging from 0 degrees C to 25 degrees C for changing three mass flow rates 0.028 kg/s, 0.031 kg/s and 0.034 kg/s. As a result, the system produces maximum 3.687 kW of electricity and the highest energy and exergy yields of the system is found as 19.76% and 9.71% at 0 celcius for 0.034 kg/s. While the energy and exergy yield decreases with the increasing of ambient temperature, it increases by the increasing of mass flow rates.