Quantifying the performance advantage of the novel passive air cooling system for PV array and system structure optimization

With the consideration of performance reliability, compared with the water cooling and the active air cooling, the passive air cooling technique without using of any pump(s) and blower(s) may be a better solution to the cooling issue of PV panels working under critical condition (high ambient temperature and no wind). In this paper, a new passive air cooling system for PV panels was elaborated. To quantify the performance advantage of this novel system and optimize its structure design, a numerical model was developed and then verified through a series of validation experiments. Following numerical analysis results showed that when the ambient temperature was 30°C, compared to the reference PV panel, the PV array equipped with this kind of passive air cooling system could have a much lower working temperature: 10°C decrease in the case of the solar irradiation intensity reaching to 500 w/m2 and over 15oc decrease once the solar radiation intensity jumps to 800 W/m2. Greater the solar radiation intensity, more benefit can be achieved from this novel passive air cooling system. In addition, the effects of main geometric parameters on the cooling performance of the system were carefully studied. Considering the balance of the cooling capacity and the manufacturing cost, the structure design with a rectangular cooling channel, relatively low channel height and rectangular chimney seems to be the optimal option for the passive air cooling system.