Heat pumps alone are not the solution to decarbonising domestic heat: they must be supported by a mosaic of solutions, including a hydrogen gas network, according to a new report by the Energy and Utilities Alliance (EUA).
The report “Decarbonising heat in buildings: Putting consumers first” takes a deep dive into UK housing stock old and new. Published in partnership with Leeds Beckett University, Cadent, Northern Gas Networks, SGN and Wales & West Utilities, the report explores the challenges of retrofitting various low-carbon heating technologies into homes of different size, age and construction, as well as customer acceptance of these solutions.
It also highlights that although energy efficiency will be crucial to net-zero targets, some measures supporting a heat pump roll-out will be intrusive to install, and less acceptable to energy customers.
In addition to examining the external building fabric, the report recommends further analysis should be undertaken to consider the internal system changes needed for heat pumps and hydrogen boilers. This includes the suitability of radiators and potential changes to hot water cylinders if combi boilers are replaced with heat pumps.
While heat pumps will play a vital role in the UK’s net-zero transition – for 7-10 million homes there are no limiting factors to installation – the EUA report findings show that for existing UK housing stock, the levels of disruption and cost, as well as lack of available space, mean that heat pumps will only be the best solution for a minority of properties.
For 8-13 million homes out of the 22.7 million that currently use gas, the lack of outside space and thermal properties of the building mean that a heat pump cannot meet the space requirement of the property or can only do so through disruptive measures such as solid-wall insulation.
Up to 4 million homes could be made suitable for heat pump retrofit through energy efficiency measures such as cavity wall insulation. However, the levels of disruption to customers, as well as the cost of significantly upgrading the electricity distribution network to cope with large numbers of heat pumps operating at peak time, means that these properties may be better served through gas-based technology and a decarbonised gas network.
The roll-out of heat pumps must be supported by a decarbonised gas network carrying a gas such as hydrogen, which is zero carbon at the point of use. The UK’s gas transportation infrastructure can be converted incrementally to support the switchover with limited disruption to customers in their homes. Several UK demonstrations of hydrogen to heat homes have already illustrated the technical and economic feasibility of a conversion.
Mike Foster, CEO of the EUA, says: “Heat pumps will play a key role in the future of heat. However, it’s important to recognise that for them to work effectively as the sole heating source, the building needs to be thermally efficient, and they require internal and external space as well as changes to internal systems such as radiators.
“Levels of disruption to people in their homes and associated costs mean heat pumps will be a solution for a minority of properties only, so hydrogen, biogas and hybrid systems need to play a significant role in the decarbonisation of heat in order to support our 2050 net-zero ambition.
“This analysis shows a house-by-house heating solution is needed, and any thoughts to carve up the UK and force regional solutions upon consumers will be doomed to fail.”
Tim Harwood, H21 programme director at Northern Gas Networks, says: “Switching to low-carbon heat is likely, in many instances, to require changes to appliances within our homes and offices, as well as the building itself. When we take these points into consideration, we need an approach that focuses on investment and people’s experience of heating technologies in equal measure as customers need to be part of this journey.”