Performance analysis of thermosyphon hybrid photovoltaic thermal collector

The conversion of solar irradiance into electricity by a photovoltaic module (PV) is 6-17% of the incoming energy from the sun depending on the type of technology and the environmental parameters. More than 80% of incoming energy from the sun is reflected or absorbed by the solar module. The fraction of energy absorbed increases with solar cell temperature and the cells' efficiency drops as a consequence. The efficiency of a PV module is improved by combining a PV module and a thermal collector in one unit, resulting in a hybrid photovoltaic and thermal collector (PV/T). The purpose of this paper is to present the behavior a thermosyphon hybrid PV/T when exposed to variations of environmental parameters and to demonstrate the advantage of cooling photovoltaic modules with water using a rectangular channel profile for the thermal collector. A single glazed flat-box absorber PV/T module was designed, its behavior for different environmental parameters tested, the numerical model developed, and the simulation for particular days for Durban weather run. The simulation result showed that the overall efficiency of the PV/T module was 38.7% against 14.6% for a standard PV module while the water temperature in the storage tank reached 37.1 degrees C. This is a great encouragement to the marketing of the PV/T technology in South Africa particularly during summer, and specifically in areas where the average annual solar irradiance is more than 4.70 kWh/m(2)/day.