- Kensa Group Managing Director, Simon Lomax, contemplates the future of heating for off-gas grid developments.
- Traditional oil or LPG boilers are not hugely favoured by purchasers and complicates compliance with building regulations.
- Air source heat pumps disfigure the appearance of the property, often require planning permission, and their efficiency has often not matched expectations, coupled with concerns about reliability and durability.
- Communal LPG systems impose huge running costs and emit high levels of carbon.
- The proposed carbon intensity factors for SAP 10 demonstrate that a ground source heat pump would emit less than one quarter the carbon of a LPG boiler and running costs would be less than half.
- Recent refinements to the Renewable Heat Incentive mean ground source heat pumps with shared ground arrays can be provided at zero cost to the house builder.
- Ground source heat pumps are now no more expensive than air source variants.
The non-domestic RHI provides a guaranteed income based on the deemed heat consumption of each dwelling featuring a individual ground source heat pump installations (at each dwelling) that is served by a shared ground array, as this system architecture is regarded as district heating. The ‘deemed’ payment, a key refinement to the RHI regulations in May 2018, enables funders to provide no-cost ground arrays: they are now certain of their income and realise the asset – the underground array – will have modest and very predictable maintenance costs.
Further benefits include:
- The specification of a ground source heat pump allows savings to be made elsewhere in the build without compromising on building regulations compliance.
- What used to be the most expensive heating system choice turns out to be the cheapest.
- Unlike traditional district schemes, householders are in control of their own heating, and able to switch providers.
- Flexible tariffs and thermal storage enable intelligent heat pump operation to capitalise on low cost and low carbon electricity.
- Ground source heat pumps have the most potential to participate in load shifting initiatives.
- Passive cooling abilities overcome overheating and costs for air conditioning.
Air source heat pumps really can’t stack up as an alternative to their less expensive, more efficient, more reliable and durable ground source heat pump cousin and the real question is the timescale for gas boilers to submit too.