Impact of liquid spectrum filter and solar tracker on the overall effectiveness of a photovoltaic thermal system: An experimental investigation

The purpose of this experimental research is to improve the electrical and thermal efficiency of an innovative photovoltaic thermal setup equipped with a Fresnel lens, a nanofluid-based liquid spectrum filter, and a dual-axis solar tracker. The nanofluid, which is a combination of water and ethylene glycol solution with 0.3 wt% of ZnO nanoparticles, was used as a cooling medium. The experiments were conducted on different days that were generally sunny, hazy, and cloudy. The maximum output power of the setup increased by 4.8% and 23.8% from no-lens to single-lens concentration and from a single-stage lens to a two-stage lens concentration system, respectively. The integration of a two-stage system with a solar tracker further enhances the output power by 6.1%. Significant enhancement in the performance of the system was achieved using nanofluid coolant and suntracking technologies. The incident solar radiation was efficiently utilized, resulting in an appreciable increase in thermal and electrical efficiency of 6.96% and 28.85%, respectively. Therefore, the proposed system is efficient and suitable for solar photovoltaic thermal applications.