Abstract
Energy regeneration through heat recovery is practically possible for maximizing energy obtained from the sun, by recovering and reusing the heat that is typically lost within energy dependent electrical equipment. Solar thermal systems utilize flat plates or evacuated tube collectors which absorb the heat from the sun. Similarly, Photovoltaic (PV) systems absorb solar irradiation to generate electricity. A combination of both technologies results in Solar Photovoltaic/Thermal (PV/T) systems wherein thermal plates or liquid contained tubes cool PV collectors resulting in increased efficiency. Solar Photovoltaic/Thermal Optimised (PV/TO) is simply a PV/T module with an improved thermal output designed and investigated in this research study. The PV cooling mechanism is important because excessive heat in PV panels generates high resistance, which impedes the performance of the solar cell and in the process, results in lower efficiency. PV/T systems are also known to produce low thermal output which makes them unsuitable for applications already serviced by market-ready solar thermal systems. The study is aimed at developing an efficient and cost effective heat recovery system which has been designed specifically to improve the thermal output without compromising the electrical output of the PV/T module. To achieve this, a survey was conducted to understand the PV/T technology market share compared to other solar technologies. Furthermore, a prototype was developed to investigate the effect of Peltier cooling method on PV cells. Two models (PV/T and PV/TO) were developed using Autodesk Inventor Professional and simulated using Autodesk CFD Simulation. The results from the simulations were then used with support from the mathematical models developed to determine the economic performance study of the two models. The survey results showed that only 11% of the respondents are actively participating in PV/T related matters. The experimental results showed that Peltier cooling improves performance by 1.1% higher than conventional cooling methods. The results from economic performance study showed that PV/TO model can archive over 100% solar fraction for the DHW demand of 800 litres/day using only 4 panels whereas PV/T model for the same demand and panel size archives just under 80% of the solar fraction using 9 panels. The overall results showed that PV/TO model optimise thermal output by over 150% and can compete with market-matured solar thermal technologies.
M.Tech. (Mechanical Engineering)