8.5.2026
Why E.ON CZ decided to build a flexibility product for their PV customers
A few years ago, E.ON Czech Republic faced a problem that every energy supplier in Europe knows well.
Their residential solar customer base was growing. These customers were engaged, invested in their homes, and increasingly vocal about wanting more from their supplier. And yet, every time the product team tried to build a genuinely better offer for them, they hit the same wall: the margin simply wasn't there.
The solar tariff they could afford to offer looked almost identical to every competitor's. A modest export rate. Net metering. Nothing that would give a PV customer a real reason to stay.
The question they were asking
E.ON CZ's Head of Strategy and Innovations framed the challenge clearly: as energy decentralises and commodity margins compress, flexibility is a new source of value emerging in the market. Suppliers who figure out how to capture it will have something to sell. Those who don't will keep competing on cents.
The question wasn't whether to pursue residential flexibility. It was whether it was actually possible to do it fast, without risk, and in a way that customers would value.
What they built
E.ON CZ partnered with Delta Green to deploy a residential flexibility platform across a segment of their PV customer base. Customers connected their solar systems and batteries to the platform via a small plug-in device. E.ON gained real-time visibility into and control over their PV portfolio for the first time.
The platform optimised battery behaviour against grid conditions and energy market prices automatically, without requiring anything from the customer day-to-day.
On top of that, E.ON built a customer-facing proposition around it. A branded product that rewarded participating households every month for the flexibility their home generated.
The product they launched, E.ON Balance, gave their PV customers something none of their competitors were offering, a solar tariff that actively earns money for the household, month after month.
What happened
The pilot results were strong enough that E.ON CZ moved directly to product development and commercial launch. E.ON Balance is now in gradual rollout, scaling across their PV customer base.
Customer satisfaction was high. Retention was high. The proposition differentiated.
And the margin problem that had made a better solar tariff impossible? It was solved at the source by turning unpredictable PV households into manageable, flexible assets that generate value rather than absorbing cost.
