The Hybrid heat pump debate 

Politically there is no support for hybrid heating systems. They are not included in the Heat and Building Strategy, the Future Homes Standard nor any of the current grant schemes. 

Supporting the path to net zero or an unhelpful diversion?

And while it may be accepted that a fully electric system is the most desirable solution for home decarbonisation, there’s also a feeling that hybrid heat pumps do have a role to play. 

Whether as a solution where standalone heat pumps are not possible, or to ease the customer into their renewable journey, hybrid solutions do have many advocates across the industry. 

The debate was reignited following a recent consultation by the Microgeneration Certification Scheme (MCS). 

It was seeking feedback to a number of proposed changes which aim to clarify the circumstances in which a hybrid heat pump system would be compliant with the scheme’s requirements. MCS expects that, if adopted, the changes will increase the number of heat pumps installed overall. 

An MCS statement accompanying the consultation reads: “Hybrid heat pumps can have several benefits, including acting as a stepping stone to 100% heat pump solutions. 

Consequently, the updates proposed in this consultation are expected to increase the number of heat pumps being installed to support reaching the Government target to install 600,000 heat pumps a year by 2028.” 

The consultation proposes: 

  • Introducing a definition of a hybrid heating system 
  • Removing the requirement that a heat pump in a hybrid system should provide at least 100% of the calculated heat loss 
  • Introducing a minimum 55% peak power output contribution from the heat pump at 55°C flow temperature 

Bridging the gap

Other advocates for hybrid systems include the Heating and Hotwater Industry Council (HHIC) which has previously written a white paper on hybrid heat pumps as a ‘flexible route to decarbonise heat’. 

The council is concerned that the Government’s focus on full electrification of heat risks delaying action on the decarbonisation of domestic heating and hot water, and wants hybrid systems to be included in the Boiler Upgrade Scheme. 

The paper reads: “With proper government support, hybrid heat pumps can deliver on targets and forge the path to net zero without having to wait for the ‘right’ technology to enter the market.” 

Stewart Clements, director at the HHIC, said at the time of the Boiler Upgrade Scheme: “It’s important to acknowledge that transitioning directly to all-electric technology simply isn’t going to be an option for many consumers. For this reason, it’s vital that this level of support is extended to hybrid systems as a means of bridging the gap.” 

’Hybrids are the biggest opportunity for the market’ 

It’s a view shared by co-founder of Heatable, Ben Price. Heatable is an online boiler installation company, which also installs solar PV. Ben is desperate to move into the heat pump space but says he has struggled to find a solution that is currently viable. 

Ben said: “For the last 15 months or so we’ve been trying to find a heat pump solution which is economically viable for the mass market and desirable enough for our partners, but we’re facing challenges in moving into that space. 

“When someone needs to replace their boiler and is in the headspace that they want to go greener, as soon as they find out the level of cost and disruption involved, they quickly change their minds. The quickest and cheapest thing for them is a boiler replacement. 

“I think hybrids are the biggest opportunity for the market by a country mile. I think we could make it work because we’d be giving the consumer the experience of a hybrid, but with the security of a boiler. This would help them get used to reducing their reliance on gas over the long term. 

“If there was a grant for hybrids I reckon I could sell them every day of the week. 

“If I knew today that hybrids were going on the Boiler Upgrade Scheme, for example, I’d start investing in training for our 500 installer partners right now. It would also get them used to working with heat pumps and then we’d be back into replacement territory, rather than retrofit, when people make the full switch later.”

Better to ‘meet some space heating needs than none’

 Smart home energy management specialists at Heatio also think the Boiler Upgrade Scheme should be extended to include hybrid systems. 

The company’s CEO and co-founder, Simon Roberts, said: “It is, of course, preferable for the heat pump to provide 100% of the load; this should always be the goal. However, if constraints within the property or the electricity supply to the property make this unfeasible, it would be more advantageous for the heat pump to meet some of the space heating needs rather than none at all. “This becomes particularly critical when considering the year-round climate variations. I do not doubt that heat pumps will fulfil a greater portion of the space heating load than current calculations predict. 

“Furthermore, we believe that Ofgem should consider extending the Boiler Upgrade Scheme to include hybrids. This would allow customers who have existing combi boilers and lack space heating to obtain a grant.  

With this grant, the heat pump would cover 100% of the space heating load, while the boiler would continue to provide hot water. Such an expansion would make heat pumps accessible to homes currently unable to accommodate a hot water storage system. 

“We also recommend the incorporation of monitoring systems in any hybrid installation to accurately gauge the energy supplied by the heat pump and to inform customers on how to enhance the use of renewable energy in conjunction with solar and battery systems. 

“The Heatio Flexx platform offers homeowners a hybrid system, equipped with a user-friendly dashboard at no cost. This dashboard enables users to monitor their electricity and gas consumption, identifying optimal times for heat pump use to reduce fossil fuel use and maximise energy savings.” 

‘Ongoing need for a hybrid solutions in some homes’ 

Grant UK has been supplying hybrid products for over a decade and continues to see an ongoing need for a hybrid solution in some homes. 

Neil Sawers, Grant UK’s commercial technical manager, said: “Here at Grant UK, we strongly feel that hybrid products have an integral part to play in decarbonising home heating. 

“We have supported the case for heat pump hybrid systems for many years and this is why hybrid technologies have been a part of our R&D focus, with the development of our VortexAir oil boiler/heat pump hybrid, and, more recently, the EvoLink Hybrid System Hub, which combines an Aerona³ heat pump with an existing fossil fuel boiler. 

“While heat pumps on their own are suitable for a large number of dwellings in the UK, there still remains a substantial number of properties which require a significant amount of improvements to be made to their insulation or energy efficiency, improvements which could be out of reach for the homeowner or landlord. 

“It is in these cases an alternative solution may be needed and this is where hybrids have their place. By installing a hybrid, the owners of these types of properties can still install a renewable heat source but they can spread the costs of their home improvements over time.” 

The importance of an exit strategy 

Adding a word of caution to the hybrid debate, the Heat Pump Federation’s director for growth and external affairs, Bean Beanland, said: “I’m not against hybrids and I don’t think our members are, but we need to lead with the concept that the heat pump is correctly sized so it can do the whole job. There’s always the potential that various fuels will be banned by legislation, or that the boiler could fail before the heat pump; you don’t want the consumer to be in a situation where the heat pump also needs replacing because it’s undersized. 

“It’s really important that the consumer understands the exit strategy so they can make an informed decision. 

“In terms of hybrid as a route to get people comfortable with the technology, I’m of the view that people are already used to heat pump technology – they use it to keep their food fresh.” 

What do you think about the hybrid solution? We’d love to hear your views. Share them with us by emailing linda@renewableenergyinstaller.co.uk

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