Innovation trial shows how to unlock flexibility from residential heat pumps

We have published results from our flagship EQUINOX innovation project, which explores how households with heat pumps can help manage electricity demand while staying warm and comfortable.

EQUINOX (Equitable Novel Flexibility Exchange) tested new, easy‑to‑understand billing approaches that rewarded customers for shifting their heating patterns at certain times of day.

With more than 1,800 households taking part, EQUINOX is one of the UK’s largest trials exploring domestic heat pump flexibility. The innovation project tested real‑world performance during peak winter demand events, assessing customer comfort, supplier propositions and technical response.

Key findings show that:

• Customers shifted heating use without noticeable comfort loss.
• Heat pumps can reliably help reduce pressure on local networks during busy periods.
• Suppliers did not require bespoke products to make heat pump flexibility work at scale.

The project also found strong interest from participating households and suppliers, showing that simple, customer‑friendly design is key to engagement.

Ryan Huxtable, Innovation Programme Lead at National Grid Electricity Distribution, said: “Customers will be relying on us more than ever before as they connect heat pumps and other low-carbon technologies, so it is important that we look at innovative ways to balance demand at key times.

“Our trials show heat pump flexibility can help manage the demand on electricity through the distribution network.

“Throughout the trials, households were able to shift heating use while maintaining comfortable indoor temperatures.”

The results demonstrate the role that flexibility can play in helping manage the system as more households adopt heat pumps, alongside network upgrades needed to support long‑term demand.

EQUINOX was an Ofgem Network Innovation Competition funded project delivered in collaboration with Octopus Energy, ScottishPower, Sero, Guidehouse, Passiv UK, National Energy Action, West Midlands Combined Authority, Welsh Government and SP Energy Networks.

Octopus Energy and ScottishPower, two energy suppliers who participated in the project, are already using the knowledge gained from EQUINOX into their business-as-usual operations.

Kieron Stopforth, Head of Flexibility at Octopus Energy, said: “Heat pumps aren’t a strain on the grid – they’re part of the solution. EQUINOX shows that with simple, fair incentives, customers can shift their heating with no loss of comfort. Smart flexibility like this keeps bills down, eases pressure on the grid, and helps power Britain’s clean energy future.”

We have seen the impact of the EQUINOX project through:

• Increased heat pump flexibility registrations, over 8,000 in total
• Improved network planning for customers with heat pumps and on time of use tariffs
• Implementing demand turn up flexibility procurement

Following feedback during the project, we have developed a new Equitable Participation Framework to help industry to target heat pump support more effectively and ensure all customers benefit from flexibility services.

Key findings from EQUINOX and all project reports are now available here.

The team will be running a series of webinars to talk through the details.

You can view an explainer of the project here.