Amsterdam, 21 September 2026 - Centrica Energy and Return have signed long-term Virtual Tolling agreement for 100 MW / 400 MWh of battery storage flexibility in Germany. The contracted capacity is not tied to one dedicated battery project. Instead, it is provided through Return's Virtual Flexibility Portfolio (VFP), bringing together capacity from Return-owned battery storage assets across Germany.
The structure gives Centrica access to Return’s virtual flexibility portfolio, creating greater diversification and resilience, while the underlying capacity remains backed by physical battery energy storage systems (BESS). Rather than relying on one dedicated asset, capacity can be provided from across Return’s broader German battery portfolio.
The deal marks a new partnership between the two companies and brings together complementary strengths: Return provides the physical battery assets and operational expertise, while optimisation will rely on Centrica Energy’s established multi-market optimisation service, with participation across Wholesale Markets and Ancillary Services in Germany to commercialise the flexibility in the market.
Cassim Mangerah, Managing Director of Centrica Energy, said:
"Flexibility is what makes a renewable-led system work, and this innovative agreement with Return helps bring more of it to the German market. Accessing 400 MWh across a portfolio rather than a single site gives us a more resilient route to market and scaling it in Europe’s largest power market is part of how we energise a greener, fairer future.”
Sjoerd Bazen, Managing Director at Return, added:
"This agreement demonstrates how our Virtual Flexibility Portfolio can provide an offtaker with access to flexibility across a broader portfolio of physical assets rather than relying on one dedicated battery. Centrica's trading and optimisation expertise lets us put our German battery portfolio to work at scale through a single partnership. That foundation allows Centrica to click in additional flex capacity as required."
As renewable generation continues to expand, the German energy system requires increasing amounts of flexibility to balance supply and demand. Battery storage can respond quickly to differences between when renewable electricity is generated and when it is needed, helping the system integrate growing volumes of renewable energy.
By combining Return's physical battery portfolio with Centrica's trading and optimisation capabilities, the partnership provides a scalable way to bring that flexibility to market. As Return's portfolio develops, capacity can be managed across a wider set of assets rather than being linked exclusively to one site. Together, the Virtual Tolling structure and Return's VFP connect physical battery capacity with the market expertise needed to optimise that flexibility effectively.
