Passive cooling technology for photovoltaic panels for domestic houses

The efficiency of photovoltaic panels decreases as the panels’ temperature increases, which results in deduction of electricity generation. In order to reduce this effect, different cooling methods were proposed and investigated. This paper reviews the previous work on PV cells cooling and concludes that the cost effectiveness, design feasibility and minimal energy consumption are the important design consideration for cooling systems. This paper reports a passive cooling method which utilises rainwater as cooling media and gas expansion to distribute the rainwater. The gas expansion is driven by solar radiation so that it can pump the collected rainwater to flow over the PV cells proportionally with the strength of the solar radiation. The paper reports a design and simulation of such a system for a domestic house application. In the paper, a relationship of the gas chamber size, solar radiation and gas expansion volume was established for evaluation with respect to the variation of gas temperature and the amount of rainwater used for cooling. A heat transfer model was used to evaluate cells performance by cooling with this passive device. The results show that on a design day, the passive cooling system reduces cells temperature and increases electrical efficiency of the PV panel by 8.3%. The payback period of this system is less than 10 years, which means the cooling system is economically feasible.