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 sun-tracking 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.