Annual performance evaluation (energy and exergy) of fully covered concentrated photovoltaic thermal (PVT) water collector: An experimental validation

In the present communication, an experimental set up of single unit of fully covered concentrated photovoltaic thermal (CPVT) collector is designed and fabricated to achieve thermal as well as electrical gain. This system is installed at the rooftop of the building of Centre for energy studies, IIT Delhi, India. Here, semitransparent PV module is used to cover the collector. The monthly observations are taken in clear sky day condition for (September 2015 to August 2016). Two cases are considered on the basis of receiver rotation according to sun movement, to study the annual behaviour of present system, case (i): fixed position and case (ii): manual maximum power point tracking technique (M-MPPT). The manual tracking is adopted for 3 times/day in a 3 h interval (09.00-12.00-15.00 h). Consecutive days are selected for taking observation for both cases (i-ii) in each month throughout the year. The validation has been found to be fair agreement between theoretical and experimental results by calculating correlation coefficient (r) and error (e). It was found that case (ii) is dominating for overall thermal energy as well as exergy gain. The annual net thermal energy and exergy, obtained by case (ii), were 1.25 and 1.19 times higher than for case (i).