Design and performance evaluation of a novel solar concentration PVT system with dual-runner nanofluids optical filtering

This paper presents the design of a novel concentrated solar dual-runner photovoltaic/thermal (DPVT) system with multi-mirror concentrator and nanofluid optical filter. The integrated evaluation of optical, operational, economic and environmental protection performances of the DPVT system is conducted. Ag/water nanofluid is used as the optical filter, of which the average transmissivity and absorptivity are 67.21 % and 32.79 %. The ray tracing method is experimentally validated by using an experimental setup and then employed to simulate the solar concentration process, revealing the technical feasibility of the DPVT system. The results also reveal the acceptable sun tracking error adaptability of the DPVT system. The ray tracing and computational fluid dynamics (CFD) coupled method is used to evaluate the operation performance of the DPVT system. The results reveal that the electric power, overall electric, thermal and overall exergic efficiencies of the DPVT system are 1538.94 W, 17.95 %, 71.72 % and 23.48 %, respectively. The appropriate decrease in the inlet nanofluid flow velocity and environmental temperature, or the proper increase in the inlet nanofluid temperature can improve the overall operation performance of the DPVT system. For the DPVT system, the levelized cost of electricity is about 0.029 $/kWh, the annual fuel cost saving for supplying heat can be 162.8 $, and annual emission reductions of soot, SOx, CO2 and NOx are 48.8 kg, 83.8 kg, 3403.5 kg and 79.2 kg, respectively.