Theoretical modelling and experimental studies to predict the performance of a solar hybrid photovoltaic thermal system

Abstract

Energy is one of the prime needs in the development of any nation and the welfare of its newlinecitizens. The excessive exploitation of fossil fuels for the production of energy causes newlineecological devastations. In an attempt to mitigate global warming and related newlineenvironmental damages, focus towards a renewable energy based world economy is newlineemerging fast. Solar energy is one of the most widely adopted renewable energy sources newlinethat can be used for domestic and industrial applications. There are two distinct newlinetechnologies available for harnessing solar energy: solar thermal technology and solar newlinephotovoltaic (PV) technology. In spite of the advantages of the solar PV technology, its newlinemajor disadvantage of low electrical conversion efficiency limits the wide spread use of newlinethis technology. Solar PV cells absorb up to 80% of the incident solar radiation but convert newlineonly a small fraction into electricity. The remainder is converted into heat, resulting in a newlinetemperature rise of the solar panels. The high operating temperature of the solar cells leads newlinein reduction of electrical conversion efficiency. Effective cooling of photovoltaic cells is newlinenecessary, especially under high insolation levels as the electrical efficiency of PV cells newlinedrops significantly with increase in the operating temperature. To overcome this major newline newlinedisadvantage and to effectively utilise the heat generated in the panels, hybrid photovoltaic- newlinethermal (PV/T) technology is developed. A hybrid PV/T system simultaneously converts newline newlinesolar energy into heat and electricity. newlineIn the present work, the performance of a double pass photovoltaic-thermal hybrid solar air newlineheater is analysed theoretically and experimentally. Active air cooling of the PV system is newlineimplemented by the use of a blower. For the enhancement of heat dissipation from the newlinepanels, three simple and economical heat transfer enhancement devices are incorporated.