I can't think of a combination that gives better household energy running costs than a heat pump and solar PV.

@heatpolicyrich Heat pump & solar thermal with inter-seasonal thermal storage ?

@theolodian @heatpolicyrich Also depends on the heat demand…

@ECO2H2OUSE @theolodian @heatpolicyrich Depends where you are but Aquifer Thermal Energy Storage works a treat at scale dutch-ates.com