Comparative enviro-economic assessment and thermal optimization of two distinctly designed and experimentally validated PV/T collectors

Abstract

This article evaluates and compares the enviro-economic potential of two distinctly (parallel flow and serpentine flow) fabricated PV/T water heating systems in view of their respective thermal optimization. A one-dimensional steady-state heat transfer model along with the concept of least entropy production yields around 20 lh−1 being the optimal flow which corresponds to highest thermal exergy of 1.5 and 1.8% for the two systems under consideration. The modeling results reveal an appreciable validation with the experimental data which correspond to maximum increment in DC power by 17.7 and 19.3 W complimented by their low-grade water heating applications worth 493.5 and 530.8 W, respectively. The mitigation potential of both the systems is well appreciated through certain pre-defined parameters as an outcome of the economic modeling. An additional 35–40% increment in total efficiency corresponds to almost 7–8% gain in electrical power with respective (parallel and serpentine) thermal configurations. Both the systems unanimously contribute 15 and 18% increment in their respective exergy-based mitigation potential as compared against 85 and 97% increment in energy-based enviro-economic parameter with respect to solo PV installation. Exergy-based performance indices show smaller increment with respect to energy-based EPI for both the designs, while energy payback period of the serpentine-based thermal installation falls 3 years shorter than a standard 255-W reference PV module.