Optimal design and operation of PV-battery systems considering the interdependency of heat pumps

•Optimal design and operation of PV-battery systems combining heat pumps.•Sensitivity analysis was carried out with varied PV capacities and battery prices.•The use of heat pumps was found to increase the PV self-consumption generally.•The use of heat pumps was found to decrease the storage capacity generally.•The impact on the commercial return depends on the PV size and the battery price.