Use of model predictive control to increase the energy efficiency of domestic solar thermal heating system

Solar thermal heating system relies on efficient use of available solar radiation. Traditional systems use temperature sensors to directly measure actual parameters and controls are used that react accordingly. In this article use of model predictive control is analyzed to use the temperature of the water leaving the top of the tank (load temperature), which increases with an increase in solar radiation, as a control signal for lowering setpoint for auxiliary heater placed inside the storage tank. Results show that the use of prediction horizon 24–72 h increase solar fraction and reduce necessary auxiliary energy of the system. Monthly analysis shows that a longer prediction horizon performs better in most cases.