Optimisation of life cycle performance of a double-pass photovoltaic thermal-solar air heater with heat pipes
A double pass photovoltaic thermal-solar air heater (PVT-SAH) system integrated with heat pipes was developed with the aim of using it for applications that require high-temperature air. A dynamic model was first developed and validated to predict the electrical and thermal performance of the PVT-SAH system with heat pipes and inform an analysis of economic benefits. A life-cycle saving method was employed, and an uncertainty analysis was included to investigate the economic performance of the proposed system in comparison with the performance of a benchmark design. The optimal designs for maximising electrical and thermal efficiencies of the new PVT-SAH system were obtained for several system lengths through a multi-objective design optimisation strategy. The PVT-SAH systems with heat pipes had higher capital construction costs than the benchmark designs but can still offer an annualised life cycle saving that ranged from A$925 to A$4606 and a payback time between 5.7 and 16.8 years. The PVT-SAH system with heat pipes was also found to deliver more efficient cooling effect to the PV panel and improve the temperature uniformity of the PV panel. The temperature variation along the length of the PV panel for the proposed system and for the benchmark design was 9.4 °C and 21 °C respectively. In addition, the maximum thermal efficiency of the PVT-SAH with heat pipes was 69.2% compared to 61.7% for benchmark design.