MCS (Microgeneration Certification Scheme) expects the proposed updates to its Heat Pump Design Standard will increase the number of heat pumps installed.
Currently, the MIS 3005-D: Heat Pump Design Standard requires that a ‘heat pump should be selected that will provide at least 100% of the calculated heat loss’…unless ‘reasonable justification can be given’.
This means hybrid systems are only allowable for MCS certification if there’s reasonable justification as to why the pump can’t be sized to provide at least 100% of the calculated heat loss.
As it stands, there’s also no minimum sizing requirement for the portion of heating which is to be delivered by the heat pump. The concern is this could lead to the installation of poorly performing systems.
Industry feedback has suggested that the lack of guidance around sizing and lack of clarity around what constitutes ‘reasonable justification’ is restricting the installation of such systems.
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
Feedback is also sought on whether the heat pump should always be prioritised in a hybrid heating system, or if there should be a set minimum of heat supplied from the pump.
The consultation closes at 10am on Monday, March 11.
The hybrid heat pump debate
Although hybrid systems are considered by some as a ‘stepping stone’ to all-electric solutions, they’re not eligible for government funding, leading to much debate across the industry.
The Heating and Hotwater Industry Council (HHIC), for example, has previously called for more support for hybrid systems as part of the net zero strategy, saying this type of solution ‘bridges a gap’ and provides a ‘practical method of achieving low-carbon heating for consumers’.
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.”
Shared view
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.”
‘Ongoing need for a hybrid solution 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.”
Responding to the MCS consultation
In response to the MCS heat pump design consultation, Neil added: “The consultation proposes a minimum of 55% of the property’s heat loss to be met by a renewable technology, and this is reasonable and achievable for most cases. For properties where this 55% target cannot be achieved, then remedial work should be taken to achieve this goal.
“There is no doubt that we need to move away from fossil fuel installations where the same size boiler is installed to replace an old appliance. If we can offset some of the boiler’s workload, such as substituting 55% of the load to a heat pump then, as the electrical grid decarbonises, we will be making even more of an impact.
“This impact could be even greater if you consider HVO as an alternative to kerosene in off-gas areas, an additional 90% carbon reduction could be achieved when using the boiler to assist the heat pump. This is a no-brainer.
“The heat pump hybrid products that Grant UK supply have proven to be very successful, helping many hard to heat homes begin their transition to low carbon heating. In the context of this proposal, by installing one of our Aerona³ R32 heat pumps together with the EvoLink Hybrid System Hub, with the heat pump fulfilling a minimum 55% contribution to the heating system, properties with a heat loss of up to 25kW would be able to meet the requirements for a MCS installation.
“What is going to be crucially important is that full room-by-room heat loss calculations must be carried to ensure that the heat pump can satisfy at least 55% of the output at the design conditions.”
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.