EQUINOX is a Strategic Innovation Fund-supported project led by National Grid Electricity Distribution investigating the potential for heat pumps to support electricity grid flexibility.
Energy Capital partnered with this project to help us learn more about how flexibility from heat pumps can be made accessible and beneficial to all West Midlands residents, and to better understand how heat pump flexibility can help us plan energy infrastructure more strategically - saving money for customers by lowering energy bills and contributing to an equitable low-carbon energy system.
The results help us understand how we can make green heating cheaper and greener still. During the three-year project, participating heat pump users were asked to turn down (and turn up) their heat pumps during peak energy demand periods, to help save energy and support the electricity grid.
Why was WMCA involved in this study?
Energy Capital supported the project as a partner as part of its aim to reach net zero emissions by 2041. The results will help us to understand how we can unlock local flexibility for a smarter local energy system, how we can do so in a way which enables a fairer net zero transition for our communities, and how we can embed this understanding into smarter spatial planning. Understanding the business case for heating flexibility offerings will also help us to create innovative business models and financial products toa accelerate the delivery of smart energy systems.
What did it find?
The project found that customers can offer meaningful flexibility for electricity grids. This means that grid operators and energy suppliers can utilise many individual heat pumps at once to shift demand away from peak periods and provide flexibility to the grid that can reduce the immediate need for energy infrastructure upgrades – this ensures a more reliable, resilient and cost-effective system for everyone.
Crucially, the project found that for most people taking part in EQUINOX, they experienced no or very little change in comfort during trial ‘events’: the times they were asked to turn their heat pumps down for between 2 and 4 hours. Where households did experience discomfort, feedback indicated they could easily manage this – such as by putting on a jumper, or engaging in more active activities.
Average demand profile of EQUINOX trial two participants across all events, showing demand response during 5-7pm events.
This was really important for WMCA to understand: the West Midlands as a whole is the region with the highest fuel poverty rate in England and safe, affordable Homes for Everyone is a Mayoral Priority.
We shaped the third trial of the project in 2024-2025 by developing an Equitable Participation Framework to make sure we were capturing and understanding all the ways people might find it challenging to engage in heat pump flexibility offerings. The EPF enabled the project to develop recommendations to support different households to engage with heating flexibility offerings fairly, as well as to develop hypotheses to ensure the project helped inform future heating flexibility offering design. This framework can also be used in other projects looking at other opportunities for people to take part in energy markets.
During the project, no significant difference was observed between the ability and willingness of households to participate in heating flexibility offerings, or in their comfort during events, although we would encourage further research into this. We also identified the value of working with trusted partners and intermediaries, such as housing associations, to help people to engage with heating flexibility offerings.
Three project trials took place between 2022 and 2025. The first trial focused on identifying if heat pump flexibility from individual households is possible, while the second and third trials focused on how heat pump flexibility from individual households could work in the existing electricity network and market. The latter trials also sought to understand how people in more vulnerable situations can engage with heat pump flexibility and receive fair benefits from doing so. In Energy Capital, we are also keen to understand how much flexibility can be unlocked though well-designed heat pump flexibility offerings, and are seeking to embed this in our future Local Area Energy Planning processes.
In each trial, participating households were invited to turn down their heat pump during specific time periods in return for payments via their energy bill or other energy supplier-based rewards. They were also invited to take part in surveys and interviews about their experiences during events.
Data was gathered on how much households were able to shift their heating demand (their electricity demand) through their heat pump, as well as their experience and any challenges they faced when doing so. This was then analysed to inform the project’s results.
If you’re interested in reading more about the project, you can access all publicly-available information about the study from the project webpage here.
EQUINOX was an innovation project supported by Ofgem and funded through the regulator’s Network Innovation Competition. The project sought to test new commercial arrangements to reward households for temporarily altering their heating choices without compromising on comfort. EQUINOX will save consumers money by lowering energy bills and mitigating costly system upgrades, while contributing to a more resilient and equitable low-carbon energy system. EQUINOX is led by National Grid (Electricity Distribution), in collaboration with Octopus Energy, ScottishPower, Sero, Passiv UK, SP Energy Networks, Welsh Government, West Midlands Combined Authority, National Energy Action, and Guidehouse.