Reasonable optimization of the operation strategy is essential for saving energy in the long-term operation of heat pump systems. However

the strategy optimization process is susceptible to load uncertainty

which causes the optimized strategy to save less energy than expected. To address this issue

a method of operation strategy optimization using stochastic load prediction was developed in this study. The method adopts multiple stochastic process samplings to simulate the uncertainty of the load prediction

thereby improving the robustness and energy savings of the operation strategy. The energy-saving properties of the optimization method were verified and analyzed using an air-source heat pump hot-water system. The results show that the novel optimization strategy can reduce the chance of using peak electricity and increase the utilization of off-peak electricity. In the long-term operation simulation

the novel optimization strategy was found to save 6.4% of energy costs compared with the traditional optimization method.