The performance of a conventional ground-source heat pump (GSHP) has been measured in the laboratory with alternating current (AC) and direct current(DC) operation using the standardised points fromEN14511:2018. The results from these measurements have been used to modify a variable speed heat pump model in IDA Indoor Climate and Energy (ICE) and the annual performance of AC and DC operation have been simulated for an entire year's operation at two geographical locations in Sweden. Results show that the energy savings with DC operation from laboratory measurements span between 1.4{5.2% and when simulating the performance for an entire year's operation, the energy savings vary between 2.5{3.4%. Furthermore, the energy savings from the simulations have been compared to the bin method described in EN14825:2018.