IMPORTANT: The heating system will not be fully confirmed until we have results from our energy modelling study.
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. However, since the homes will have such a low heating demand we are also modelling how cost effective a simple resistive heating system could be.
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 funded by the Rural Community Energy Fund and working with Buro Happold.