Managing overheating in a solar thermal plant with trackers using dynamic optimization

• Flow rates and tracking angle of solar collectors were economically optimized. • The economic objective function includes overheating costs. • Scenarios with a parameterized and an optimized tracking angles were compared. • Optimizing the tracking angle reduced the overheating cost by 98.9% • Optimizing the tracking angle reduced the electricity consumption by 44.8% High solar irradiation combined with low heat demand can cause overheating in a solar thermal plant which can lead to equipment premature aging and damage. In this work, a dynamic optimization of flow rates and tracking angle of the flat plate solar collectors is studied to prevent overheating. An economic objective function is employed, maximizing the heat profits while considering the operating costs, including the costs associated to overheating. A case study where overheating is likely to occur was considered, and a scenario with a parameterized tracking angle is compared to an optimized tracking angle, with optimized flow rates for both scenarios. The results show that optimizing the tracking angle and defocusing the solar collectors when solar irradiation is too high, can avoid overheating and achieve better economic performance than only optimizing the flow rates. The overheating costs between the two scenarios were reduced by 98.9%, and the electricity consumption was reduced by 44.8%. This is the first study considering the optimization of the tracking angle to manage overheating, and it shows the importance of including trackers in the solar field and optimizing the tracking angle during operation.