Comparison of control approaches for variable speed air source heat pumps considering time variable electricity prices and PV

Results show that the MPC approach reduces annual operating cost by 6-11% for constant electricity prices and 6-16% in the case of variable electricity prices. Rule-based approaches lead to cost reductions of 2-4%. MPC could increases PV self-consumption from 56% to 58% up to 64-71%. The rule base approaches are found computationally less demanding and easier to design. However fine-tuning has been considerable work and with changing boundary conditions rules had to be readjusted. It showed that increasing thermal storage without MPC is not beneficial and optimised controls are a prerequisite to benefit from increased storage sizes.