Optimal switching control of PV/T systems with energy storage using forced water circulation: Case of South Africa

摘要

In this paper, the optimal switching control of flow in hybrid PV/T systems with forced water circulation is presented. Actual historic exogenous data obtained from a weather station in the considered area is used as input for the established model.The aim was based on developing an optimal control model to maximize the energy output of the PV module using water circulation to collect the heat and persevering in maintaining the surface temperature as minimal as achievable.Comparisons between the baseline and the proposed model yields an output power improvement of 2.65% during summer, whereas a 5.90% deterioration during winter. Therefore, the simulation results further demonstrate the proposed model yields a daily heat gain of 9.37 × 107 J, 26.03 kWh inside the water storage tank during the selected summer day and 2.61 × 107 J, 7.25 kWh during the selected winter day.A true payback period (PBP) analysis is presented, where the project lifetime is chosen to be 30 years. The PBP analysis shows it takes up to 4 years and 2 years for the investor to generate profit from the standard PV system and the optimal switching control model, respectively. However, when looking at both systems over their predicted lifetime, the optimal switching control strategy generates a higher profit of 92.41%.