EXECUTIVE SUMMARY
A long-term Virtual Tolling agreement gives Centrica Energy access to 100 MW / 400 MWh of battery storage flexibility through Return’s German portfolio. The arrangement aggregates capacity from multiple physical battery assets, with Centrica providing multi-market optimisation across wholesale electricity markets and ancillary services.
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Centrica Energy is the energy trading and optimisation business of UK-based Centrica plc, and Return have signed a long-term Virtual Tolling agreement covering 100 MW / 400 MWh of battery energy storage flexibility in Germany. The agreement establishes a partnership between the two companies, combining Return’s physical battery storage portfolio with Centrica Energy’s trading and optimisation capabilities.
Unlike conventional arrangements tied to a dedicated battery project, the contracted capacity will be supplied through Return’s Virtual Flexibility Portfolio (VFP). This structure aggregates flexibility from Return-owned battery storage assets across Germany, allowing Centrica to access capacity from multiple physical battery energy storage systems (BESS).
The portfolio-based arrangement is designed to provide greater diversification and resilience by reducing reliance on a single storage site. Although the contracted capacity is virtualised, it remains backed by physical battery assets within Return’s German portfolio.
Under the agreement, Return will provide the battery assets and operational expertise. Centrica Energy will manage the commercial optimisation of the contracted flexibility through its established multi-market optimisation service. This includes participation in Germany’s wholesale electricity markets and ancillary services.
The partnership brings together Return’s battery infrastructure and Centrica’s market expertise to commercialise storage flexibility. By combining physical assets with trading capabilities, the companies aim to create a scalable structure for managing battery capacity across Germany.
Cassim Mangerah, Managing Director of Centrica Energy, said that accessing 400 MWh across a portfolio rather than a single site provides a more resilient route to market. He also highlighted the importance of expanding flexibility in Germany as renewable generation increases.
Sjoerd Bazen, Managing Director at Return, explained that the Virtual Flexibility Portfolio allows an offtaker to access flexibility across multiple physical assets instead of relying on one dedicated battery. He added that Centrica’s trading and optimisation expertise enables Return to commercialise its German battery portfolio through a single partnership.
The arrangement also provides a framework for adding further flexibility capacity as required. As Return’s portfolio develops, additional capacity can be incorporated into the partnership without being exclusively linked to an individual battery project.
The agreement comes as Germany’s electricity system requires increasing flexibility to manage the expansion of renewable energy generation. Battery storage can respond to differences between electricity generation and demand, supporting the integration of variable renewable resources.
Through the Virtual Tolling structure, Return’s physical battery assets will be connected with Centrica Energy’s market optimisation capabilities. The partnership establishes a portfolio-based approach to commercialising battery flexibility across Germany’s wholesale and ancillary services markets, with scope to scale contracted capacity as Return’s storage portfolio expands.