| Abstract: | A photovoltaic/thermal hybrid panel (PV/T) is a high‐efficiency energy converter which supplies electrical energy and thermal energy from solar energy. In this paper, we report characteristics of two PV/T types under various environmental conditions and fluid flow rates, using numerical analysis. We found photovoltaic efficiencies to be 9.61% for PV/TA and 10.56% for PV/TB at T c = 25 °C; thermal ones were 52.11% for PV/TA and 40.14% for PV/TB at Tf = 40 °C, Irr = 800 W/m2. From these results, we propose some design points to construct the optimum structure of PV/T. Next, we adopted exergetic evaluation to study electrical energy and thermal energy quantitatively. As a result, we could confirm the existence of flow rate maximizing the total efficiency (optimum flow rate) on some environmental condition, and could define the optimum operating condition. Moreover, we compare exergetic efficiencies on optimum operating conditions (maximum exergetic efficiency) under various environmental conditions with PV, PV/TA, and PV/TB. A rise of maximum exergetic efficiency with increasing irradiance yielded –3.6%/kW ⋅ m–2, +3.6%/kW ⋅ m2, and +1.4%/kW ⋅ m2, respectively. Nevertheless, we could confirm a hybridizing advantage of high irradiance. © 2000 Scripta Technica, Electr Eng Jpn, 133(2): 43–51, 2000 |
