Abstract :

The greatest challenge to the development of photovoltaic is the rise in surface temperature, especially in countries with a high solar radiation. For a silicon (Si) photovoltaic, the photons having a wavelength longer than (1.11 μm) possess energy lower than (1.12 eV) band-gap energy required for exciting an electron, their whole energy is wasted, and it only heats the cell. From the other side, the photons having a wavelength shorter than (1.11 μm) possess energy higher than that required for exciting the electron and are also dissipated as a heat loss in the cell. In this experimental study, the effects of mounting 3 mm clear acrylic sheets to the tops of photovoltaic panels in parallel or at various tilt angles with respect to the panels were evaluated. The results demonstrated that installing clear acrylic sheet will reduce the photovoltaic surface temperatures, enhance the performance, increase the electrical energy production, and extend the cell life. After mounting the 3 mm acrylic sheet parallel to the photovoltaic panel and 30 cm from the top, a reduction of 10% was resulted in the surface temperature compared to photovoltaic without acrylic. The greatest percentage drop (14.5%) in the photovoltaic surface temperature was achieved by installing clear acrylic sheet at 30◦ tilt with respect to the panel.