To meet net zero goals, local authorities are looking for innovative solutions to decarbonise transport, housing, waste, energy and a range of other services. For our latest blog, we want to focus in on the benefits, potential barriers and opportunities of one solution to low carbon heating – networked heat pumps. Balazs Csuvar, DG Cities’ Head of Delivery and Wouter Thijssen, Managing Director of Kensa Utilities, a leading UK heat pump manufacturer, explain.

What are networked ground source heat pumps?

Networked heat pumps replicate the gas grid model, whereby you have an individual heating appliance in your home (in this case, a ground source heat pump instead of a gas boiler), connected to a shared communal loop of pipework in the ground that supplies energy to this appliance (an ambient temperature heat network, as opposed to the gas grid).

Low-temperature heat can be sourced from the ground all year round. Networked heat pumps absorb this sustainable and constantly replenished heat source through pipework under the street. In each home, there is a heat pump, which is connected to this ground loop. The heat pump uses electricity to upgrade the heat from the ground and provide heating and hot water to homes.

How efficient are they?

On average, the overall energy efficiency of this system is four times greater than using direct electricity for heat, and five times more when compared to gas boiler efficiencies – for every 1kWh of electricity consumed to power the heat pump, approximately 3-4kWh of free energy is gained from the heat stored in the ground.

In effect, the system creates a district heating network. As generations of district heating systems have evolved, the temperatures circulating the district network have also been reduced, further improving efficiency – in networked heat pump systems (often called fifth generation district heating), an ambient temperature flow of below 20°C is possible. This enhances efficiencies and reduces heat losses, whilst still delivering the heating and hot water the end user needs. Ambient temperature loops are also an excellent source to capture waste heat and further improve the efficiencies of networked heat pumps.

The feasibility of a networked heat pump system has been proven; they have been rolled out commercially across the UK in a range of new developments, multi-storey social housing blocks and other, non-domestic, building types. The next boundary is to implement this system at scale in medium density urban areas, such as the residential terraced streets that make up a large proportion of the country’s towns and cities. These are areas likely not dense enough for traditional high-temperature district heating, but in lots of places, too dense for individual air-source (due to noise issues) or individual ground-source heat pumps (due to limited external space).

As part of a recent project, DG Cities and Kensa looked into the feasibility of such a system for a residential neighbourhood – here are some of the key takeaways from our study:

1. Do they work on terraced streets?

Yes. The technical and financial feasibility of the system depends, to a great extent, on the density of homes that will be connecting to the ambient temperature heat network. With a utility provider funding the ground array infrastructure, costs to householders are the same, if not lower, than for air source heat pump installations. Clustered sign-ups over time make this solution viable for the utility provider.

2. How do you design a consumer journey?

The scale of the challenge is massive. To meet 2050 targets, we need to decarbonise 28 million homes in 27 years. That is more than one million per year, or 20,000 homes per week. With that in mind, we need a scalable approach that tackles streets and regions at a time, rather than individual houses one-by-one. Clustered solutions like heat networks and networked heat pumps are great for this. The key, therefore, is to design a consumer journey that engages whole neighbourhoods at a time – a locally-driven transition. This is what DG Cities, Kensa, SELCE and the rest of the Heat Pump Ready Greenwich consortium developed together.

Initial surveys showed what we suspected: heat pump awareness in the UK remains low, with less than half (42%) of survey respondents knowing about heat pumps to varying degrees. Heat pump installation can also be a technical and unfamiliar process for homeowners, as with any new technology.

To address this, we built a ‘funnel’ approach to the consumer journey. This focused on engaging locally and starting very wide; first building up an awareness and understanding of the technology, before giving more specifics and detail about the system to enable people to make an informed decision.

 The diagram highlights the phases of the marketing funnel:

• awareness: making consumers aware of the energy debate, net zero and potential solutions, including networked ground source heat pumps. This includes site visits to existing heat pump sites where residents can talk to those who already have heat pumps, as well as demonstration heat pumps in the local area that they can see and ask questions about.

• consideration: providing consumers with more information to help them decide which technology offers are right for them. This is through 1:1 discussion (e.g. through scheduled ‘coffee hours’) where residents can ask all their questions.

• conversion: allowing people to deploy new technologies in their homes – if a networked heat pump is relevant, providing them with guidance on how to sign up to a scheme. This starts with surveys and quotes specific to their home and situation, giving them the specific details they need to make a decision.

• loyalty and advocacy: once customers have enrolled in the heat pump scheme, the focus moves to making sure customer service is positive, then using their experiences as a success story to recruit more consumers.

3. How can policy accelerate progress?

While we coordinated the key industry players to deliver the best possible consumer journey, we see several policy tweaks that could help fast-track this journey to much more rapid decarbonisation. First, rebalancing electricity and gas levies to avoid unfairly taxing the cleaner fuel of electricity. Second, going from heat network zoning to heat zoning, so that each local authority has the power to designate streets and regions ‘most suitable’ for a certain heat decarbonisation solution, based on local conditions. Third, granting statutory rights to ambient temperature heat networks to enable easier in-road deployment; matching the rights granted to electricity, gas and water utilities.

We believe these three tweaks can significantly speed up coordinated solutions, and would be a great example of a successful partnership between industry and policy to achieve decarbonisation.

Are you a local authority looking to trial a networked heating system?

Our feasibility study showed that current technologies can already make a huge difference to the decarbonisation of many terraced homes. However, for this to work, it will take significant commitment and large-scale behavioural change, along with trials and further evaluation. We are looking for local authorities that are interested in starting this journey with us – to harness a transformative, UK-leading innovation to deliver on decarbonisation goals. Please get in touch if you’d like to discuss this further.