Experimental investigation of solar photovoltaic thermal system using water, coconut oil and silicone oil as spectrum filters

In the current study, the performance of a photovoltaic thermal system with easily available and less expensive liquids as spectrum filters is analyzed. The absorption and transmission spectrum of different liquids is investigated using a UV–VIS–NIR spectrophotometer for the wavelength range of 200–2500 nm (terrestrial solar spectrum). Among all the selected liquids; tap water, silicone oil and coconut oil were found transparent to the response range of C-Si solar cell and shows absorption in UV and IR region. In the current work, the electrical performance of the solar cell with these liquids as spectrum filters is analyzed using a solar simulator at 1 Sun, AM 1.5 G. The simulator experiment shows the improvement in the electrical performance of the solar cell. To investigate the performance of the system under natural sunlight, the experiments were performed on a 10 W C-Si PV module, with 1 cm thick liquid spectrum filter in the month of April. In these experiments, an average electrical efficiency of 12.53% and average thermal efficiency of 47% was recorded. The detailed experimentation, findings and scope for further research are discussed in this article.