EXPERIMENTAL COMPARISON ON PV, PVT, AND PV/PCM SYSTEMS

Abstract

Photovoltaic thermal (PVT) collector produces thermal energy along with electrical energy when exposed to sunlight. A PVT system combines a solar cell, which produces electricity with a solar thermal collector, which extracts thermal energy from the sun. A solar panel is capable of achieving a maximum electrical efficiency of 15 to 25%, while a PVT hybrid collector produces combined energy efficiency in the range of 55 to 70%. This ability of the PVT collector to trap a large amount of the sun’s energy makes them superior over the conventional solar panels. This study is to investigate the performance of a PV, PVT and a PV/PCM system under real outdoor conditions. A 15W solar panel is used for the construction of the PVT collector. First, experiments were conducted to compare the efficiencies of the PV, PV-PCM and PV/T systems. By measuring the power output, backplane temperature, and tank water temperature, the thermal and electrical efficiencies of the three systems were calculated. The performance analyses of the PVT system shown that, these systems are four to five times more efficient than normal PV systems. The integration of a PCM layer into a PV/T panel was found to effectively reduce its heat loss to ambient. The heat stored into the PCM can be discharged into the working fluid when the solar radiation is less intensive or unavailable. Since thermal energy is also obtained from both these systems, the overall efficiency of the system increases considerably when compared to a normal PV system.