Cooling and increasing the electrical efficiency of photovoltaic modules using expanded graphite (EG)/paraffin PCMs

Solar energy is one type of renewable energy that is clean and freely available and electricity production using photovoltaic modules (PV) has received a lot of attention.The performance of a PV module severely depends on its surface temperature. Increasing about ۱۰°C in the surface temperature of a PV module causes to ۵% reduction in its electrical efficiency. In this study, PCM composite of paraffin with expanded graphite (EG) is used to augment the heat removal from the surface of a PV module. The effects of the mass fraction of EG (φ=۲-۱۱.۵ %wt.) in paraffin on the surface temperature and power output of PV module are investigated. Obtained data showed that temperature and output power are as high as ۶۴.۰۸ °C and ۴.۸۸ W, respectively, for an uncooled system. The composite of ۸۸.۵% paraffin and ۱۱.۵ % EG is the more efficient PCM. The temperature and output power of PV module at the best condition are found to be ۴۳.۱°C and ۷.۳۵ W, respectively.

Keywords:

Paraffin , PCM , Expanded graphite , Photovoltaic , Cooling.