Thermal regulation of photovoltaic system for enhanced power production: A review

Abstract

The efficiency of the photovoltaic (PV) module is drastically decreased when integrated with building material. This efficiency decrease is mainly caused due to the temperature rise of the PV module. The temperature rise is responsible for the overall decrease in voltage and power production. Only a small fraction of the solar radiation that falls on the PV module is utilized for electricity production and the rest generates excess heat responsible for the temperature rise of the PV module. The integration of the PV panel on the roof also prevents air circulation results in the accumulation of heat. There are several techniques to manage the temperature rise viz. air cooling, water cooling, thermoelectric cooling, and phase change materials (PCMs). This paper discusses the various cooling technologies that can regulate PV temperature and augment power production. The result showed that passive cooling that relies on convection is the easiest and simplest approach and does not consume additional power. Active water cooling is effective to a greater extent but there is always a requirement of cold water which may offset the benefit of cooling. The temperature up to 18 °C can be reduced and efficiency between 1 and 18% can be enhanced by PV/thermoelectric module (TEM). The PV temperature can be lowered by about 35.6 °C by using a PCM system with the PV panel. The addition of nanoparticles has a positive influence on lowering the temperature of the PV module. The temperature can be lowered up to 16 °C by using nanoparticles in the water system with PCM. The electrical efficiency can be improved by 8–10%. The integration of PV/T with PCM can increase the heat availability time by 100%. The addition of such kind of heat extraction system increases the electrical power production and better thermal efficiency is also observed. The combined efficiency of 70–80% has been achieved in many cases. For the PV/ T system, the economic payback is obtained between 20 and 25 years and the energy payback is between 15 and 20 years.