IMPORTANT: The heating system will not be fully confirmed until we have results from our energy modelling study later this year.
A passivhaus uses 75% less energy for space heating than UK new build requirements, because the houses are so well insulated and can make the most of the passive solar gain (technical term for sun coming in through windows!)
It is likely that we will use ground or air source heat pumps, possibly with thermal storage.
Heat pumps use the heat from either the air or the ground and then, powered by electricity, they condense this to provide space and water heating. With a ground source heat pump, for every one unit of electrical energy you put in, it will take approx. 3 units of heat energy from the ground and so deliver 4 units of heat energy to the homes.
It may be that each property has its own air source heat pump, or we have several larger ground source heat pumps around the site pumping hot water through a heat main (highly insulated pipe) to the homes. We are undertaking a feasibility study for this.