Earlier this week the Department for Net Zero surprised many people by quietly expanding the Boiler Upgrade Scheme (BUS) grant to include Air to Air Heat Pumps and Heat batteries.
The reason for the surprise was in the run up to the budget all the leaked announcements indicated the budget would means test the BUS grant in some way. Whilst this could still be the case, the announcement that the grant has expanded its remit is very welcome indeed!
What is the BUS grant?
The Boiler Upgrade Scheme (BUS) grant is a UK Government Grant intended to cover part of the cost of replacing a fossil fuel heating system with a heat pump or biomass boiler in your home or a building used for your business. Until now the main focus for most people has been the £7500 grant towards the installation of Air to Water heat pumps or Ground Source Heat pumps.
So the Department for Net Zero announcement that the grant has expanded to include £2500 towards an Air to Air Heat Pump or a Heat battery is very welcome.
What Heating Systems can the Grant be used to replace?
The UK Goverment website defines the systems eligible for replacement part funded by the grant as fossil fuel heating systems include oil, gas, electric or LPG (liquefied petroleum gas). It is unclear to the author exactly what electric heating systems are eligible for replacement funding by the grant, but it could be that older storage heaters or direct panel heaters for example might be classed as electric heating systems.
It may be necessary to go through the grant eligibility process to check…
Apply for the Boiler Upgrade Scheme: Check if you’re eligible – GOV.UK
Why has the grant expanded to included Air to Air Heat pumps and heat batteries?
We know that the Department for Net Zero has been consulting industry for some time as technology changes rapidly.
Whilst Air to water heat pumps and Ground Source Heat pumps are fabulous as an energy efficient low carbon replacement for radiator heating systems (see the many case studies on our Home Energy page) they do require space for a hot water cylinder and associated equipment. If you have a small apartment with old electric storage heaters it would be a considerable effort to install a wet radiator system and hot water tank. However a couple of rooms could be easily heated or cooled by an Air to Air system.
Air to Air heat pumps are very energy efficient (typically 300% to 400%) and have the advantage that they can cool as well as heat, something that might be advantageous if your home or flat overheats in the summer.
note: Whilst many air to water systems are capable of cooling as well as heating, they are not typically installed like that in the UK at present as they are viewed as a gas central heating system replacement.
The BUS grant now offers £2500 towards the installation of an Air to Air Heat pump providing you meet the eligibility criteria. There are some systems now that are capable of heating hot water as well as supplying the Air to Air units.
It is important that the installer is Microgeneration Certification System (MCS) certified. This may initially limit the availability of installers as most Air to Air installers come from an F-Gas refrigeration background and haven’t typically taken MCS certification. Similarly most Air to Water Heat pump installers come from a plumbing background and aren’t typically F-Gas certified as the refrigerant gases are fully contained within the Air to Water heat pump, but they are MCS certified.
Air to Air heat pumps have an outdoor fan unit that in many circumstances falls under permitted development in a similar manner to Air to Water heat pumps. They need to meet MCS noise requirements and this requires positioning to ensure the noise produced is 42dB or less at the closest habitable window.
In Chippenham if you have a listed building or are located in the Conservation area you will need planning permission. If you are in a multi-storey apartment building outside of these areas you may still need planning permission.
Wiltshire Council are the Planning authority for Chippenham. However the Town Council has an excellent friendly planning officer, so if you contact your local councillor you may be able to obtain some informal guidance on whether you will need planning permission.
What are Heat Batteries?
Heat batteries store spare heat or electricity, often generated by renewable energy systems. These store heat in a material that changes from a solid to a liquid and back. These materials are called phase change materials (PCM).
The best two commercial examples I know of are from Sunamp and Tepeo.
Heat batteries are a kind of modern storage heater. The battery is ‘charged’ on an off peak electricity tariff. Unlike electrical battery storage the Phase change materials don’t degrade in the same way and therefore have a longer life.
The Phase Change Material concept has also been used in some Zero Emission Boilers. The examples of Heat batteries i’ve seen to date are roughly the size of a washing machine but can be slimmer than a hot water cylinder, and so might be an alternative to a hot water tank in some circumstances. Though technology and products are changing rapidly in this area. Once ‘charged’ Heat batteries can retain heat for days at a time and are typically sized as though they are a hot water cylinder equivalent. They can also work in combination with solar PV systems.
The BUS grant offers £2500 towards the cost of a Heat Battery.
Conclusions
The expansion of the BUS Grant to include Air to Air Heat Pumps and Heat Batteries is very welcome, and perhaps something the government should shout a little louder about!
Air to Air Heat pumps offer similar 300% to 400% efficiency gains of Air to Water Heat pumps and also cool in the summer. They do however require internal units and refrigerant pipe runs so are perhaps best suited as a solution to small apartments, or where a wet radiator system isn’t already installed.
Heat Batteries use material Phase Change technology to take advantage of lower cost electricity rates or solar diversion. They require a wet plumbing system and typically replace a hot water cylinder, though technology is evolving rapidly.
So it could be for example that for a small apartment a combination of Air to Air heat pumps for heating and cooling, and a Heat battery for hot water, might be an energy efficient solution that works in a smaller space.