Green Flexibility proposes template for flexible grid connection deals

Green Flexibility has developed a template for flexible grid connection agreements based on one year of operating a grid-neutral battery energy storage system and negotiations with multiple German distribution system operators.

The company said the template draws on operational experience from its 15 MW/33 MWh battery project in Immenstadt, Bavaria, which has operated under the requirements of Allgäuer Überlandwerk for the past year, as well as 15 negotiations with different grid operators.

According to Green Flexibility, the blueprint identifies which contractual provisions have proved practical and where more restrictive approaches limit flexibility without improving grid security.

The company said the model agreement is intended to serve as a practical template for future flexible grid connection agreements between battery storage developers and grid operators. Allgäu Netz plans to use the framework to connect additional large-scale battery storage projects in its service area next year.

Volker Wiegand, managing director of Allgäu Netz, told Green Flexibility that overly broad or restrictive requirements for flexible grid connection agreements can prevent storage systems from providing flexibility to the grid. He said practical operating models are needed to maintain grid security while allowing storage assets to perform their system functions.

According to Green Flexibility, the blueprint includes dynamic power limits, a full-load-hour-based curtailment model, and coordinated control of ancillary services. The company said the approach distinguishes between grid-neutral and grid-supportive operation and bases operational restrictions on actual grid conditions rather than fixed limits.

Wiegand also said current proposals for flexible grid connection agreements from some large distribution system operators focus too heavily on restricting storage operation instead of enabling grid-compatible integration. He argued that responsibility for forecasting and operational constraints should remain with grid operators, which have access to the relevant network data and are responsible for system security.

From pv magazine Deutschland