Performance Analysis of Photovoltaic Thermal System Using Silicone Oil Spectrum Filter

Abstract

The paper reports use of silicone oil as spectrum filter and heat absorber for photovoltaic thermal systems. The terrestrial solar spectrum is in the wavelength range of 0.25 to 2.5 μm. The response range of C-Si solar cell is 0.75 to 1.125 μm. In the current study, the feasibility of Silicone oil (Transformer oil) as spectrum filter cum heat absorber for C-Si solar cell is investigated. The spectroscopic analysis of 1 cm thick Silicone oil sample with UV-VIS-NIR spectrophotometer is carried out. This analysis concludes that the Silicone oil is transparent to the response range of C-Si solar cell. Also, it shows a significant absorption for UV and IR part of the spectrum. A glass container with 1 cm thick Silicone oil layer is mounted on the C-Si PV module. The performance of the system is analyzed using solar simulator at irradiance of 1000 W/m², AM 1.5 G and in natural sunlight at Nagpur (21.10 N, 79.090 E). The experiments were performed for the entire year for time period of one hour in the noon. With Silicone oil spectrum filter, the average electrical efficiency of the PV module was found increase marginally. However, for 10 W module, 27 W average heat gain was recorded. In this study, the surface area of PV module (30 × 35 cm = 0.105 m²) was very small. In actual practice, for large scale installations, significant heat gain is possible. The experimentation and significant outcomes are discussed in this article.