Why hot water cylinders will be crucial to achieving Net Zero

Neil Hope – Head of Technical at NIBE Energy Systems – looks at the role that hot water cylinders could play in the race to decarbonise the UK:

There has been much talk over the last few years on the role that heat pumps, biomass boilers, solar thermal technology and similar sources of low carbon heat will play in reaching our Net Zero aspirations. Less has been said on the role that the more inconspicuous hot water cylinder plays in supporting the efficient operation of such renewable heating technologies. With their huge potential to act as thermal storage and domestic batteries, they are a necessity to the decarbonisation of the UK housing stock that is often overlooked and hidden away.

Despite once being a staple of English homes, the rise of the combination boiler has seen a coinciding drop in the number of installed hot water cylinders. New data from the Hot Water Association shows that less than 45% of our homes currently contain a hot water cylinder- a significant drop from 77% of homes in 2001.

In short, only 9 million English households have retained a hot water cylinder. Whilst this is not a negligible amount, it is predicted that this figure will need to double to 18 million in order for the UK to meet Net Zero by 2050. At present, there are noticeable gaps in government policy in regards to achieving this. For example, despite hot water cylinders twinning with heat pump technologies in many installs, the government has only made targets to deploy heat pumps. Indeed, 600,000 heat pumps are to be installed annually by 2028. If such a target is to materialise into a reality where heat pumps are the UK’s primary heating technology, the installation of hot-water cylinders must also become part of the conversation.

More specifically, the re-installation of millions of hot water cylinders must be encouraged by the government. In doing so, the issue of the space requirements for cylinders must also be addressed. With many households choosing to renovate areas previously allocated to cylinders into bathrooms and additional storage, asking for a reversion of such domestic transformations will be a challenge. Fortunately, new space-saving solutions are being developed which will allow cylinders to be stored in less commonly used areas, including lofts and garages.

This is where new build regulations could help. We have called on the government to ensure that new homes are heat pump ready. This means, among other things, providing space for a hot water tank to be installed later, if not at the point of development. This provision will make it easier and more cost effective to deploy heat pumps in homes built before 2025, when the Future Homes Standard comes into force.

At NIBE, we understand the importance of having high quality hot water cylinders which offer both safety and optimal performance. Our highly efficient cylinders are specifically designed to work alongside our heat pump range to minimise heat loss. They can also be paired with solar panels or other heating solutions to provide a holistic solution. As an added benefit, they are stylish and modern in appearance, meaning that they do not need to be hidden from view.

As part of our NIBE Pro Installer programme, we offer technical support and training when it comes to the sizing and selection of hot water cylinders. Many other industry bodies have also developed training courses in preparation for the necessary resurgence in hot water cylinder installations. Two notable examples are the Heat Pump Association and the Chartered Institute of Plumbing and Heating Engineers, which offer low temperature heating and hot water design courses. Such courses build upon your awareness of heating design to support the installation of systems that are efficient and best suited to your customers’ needs.

The humble hot water tank will be an integral part of our domestic heating set up. Playing an important role in our future energy system, hot water cylinders will offer system balancing and allow consumers to use energy when it is cheapest and most sustainable. Next time you discuss your low carbon solutions with your clients, don’t forget to mention the advantages of installing one.

For more information, please visit: www.nibe.eu/en-gb