E.ON Next's pioneering flexibility trial showcases how lower bills, a stronger grid and renewables can thrive together

E.ON Next has launched a pioneering new trial designed to demonstrate how lower energy bills, greater grid flexibility and accelerated renewable growth can be delivered simultaneously.

For too many years, reduced energy bills, greater grid flexibility and renewable ambition have been treated as mutually exclusive ideals – never being fully achieved at the same time. A new trial from E.ON Next is challenging that assumption, demonstrating how flexibility can deliver benefits across the system, from households to network operators and renewable generators.

Building on learnings from E.ON’s original Coventry battery pilot in 2024, the second phase of the project will see up to 100 homes fitted with batteries to show how customer demand flexibility can unlock lower bills for struggling households while simultaneously reducing pressure on the electricity grid and supporting the growth of renewable generation.

“This trial shows that lower bills, grid flexibility and renewable growth don’t have to be trade-offs,” said Ramona Vlasiu, Chief Operating Officer at E.ON Next. “By putting the right technology in the right place, we’re showing that flexibility can deliver real value: making energy more affordable for households, strengthening the UK’s energy system so it is fit for the future, and enabling us to rely more on home-produced renewable energy sources.”

This trial builds on the design and learnings of the original pilot, which saw the first fully funded battery installations delivered to vulnerable households and offers a clear example of how innovative approaches to flexibility can help turn long-standing challenges into shared successes.

E.ON Next is also running a parallel trial in Glasgow aimed at demonstrating how batteries can be used to support the most vulnerable families to ease child poverty across the city.

This second battery trial across Coventry is another element of E.ON Next and Coventry City Council’s 15-year Strategic Energy Partnership, focused on modernising energy use across the city.

The home batteries will be fitted to eligible homes without upfront cost, meaning families can store electricity when it is abundant and cheap – ready for use when demand, and prices, are highest –  enabling customers to rely less on expensive peak-time power. Early data indicates meaningful bill savings of up to £360 a year per household, driven by each customer receiving a guaranteed payment of £30 per month, without needing customers to change their daily routines or behaviours.

The results also point to wider system benefits, with increased flexibility helping to ease grid constraints at peak times, reducing the need for costly, time-consuming network reinforcements or upgrades. It also lowers the volume of renewable energy that must be curtailed during periods of excess generation – a growing challenge as wind and solar capacity accelerates across the UK. This isn’t the first time E.ON Next has conducted pilot studies into the effects of batteries on grid load – the 2025 project in conjunction with Northern Powergrid showed positive results in this space.

Curtailment costs have become an increasing burden on the energy system and a barrier to renewable ambition, driving up costs that are ultimately passed on to consumers. Recent figures suggest that curtailment costs have tipped £1 billion for 2025 and could actually be as high as £1.5 billion, with nearly £400 million of that being paid to renewable energy generators to sit idle. This equates to £34 per household, up from £15 in 2023.

By reducing or removing these constraints which hamper renewable energy use, the trials show how flexibility can cut waste, lower system costs and allow renewables to provide a greater, more consistent share of electricity demand.

Vlasiu continues: “E.ON Next continues to explore what is possible when we look at the issue as a whole and trying to address the root cause rather than the symptom. By combining technology with accessible energy systems. innovative thinking and direct action, we can deliver a flexible energy system that benefits everyone. We are showing how more reliable, clean energy systems and less grid constraints, as well as increased energy security as a nation result ultimately in more affordable, predictable energy bills for households. We are doing everything we can to make this an affordable reality for all, and we would welcome the government continuing to prioritise these ambitions through mechanisms such as ED3 and other legislation.”

E.ON Next believes trials like this are essential to proving that flexibility is not a future concept, but a practical, real-life solution that can be deployed today – helping to build a cleaner, cheaper and more resilient energy system for tomorrow.

As the UK accelerates towards a low-carbon energy future, E.ON Next’s trial is part of E.ON and Coventry City Council’s long-term Strategic Energy Partnership in the city.

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