Germany lets batteries mix solar and grid power without losing support

Victoria Shinder02 October 2026, 17:372 min read

Germany's Federal Network Agency, the Bundesnetzagentur, has approved its long-awaited rules for the market integration of storage systems and charging points, known as MiSpeL, pv magazine reports. They let batteries combine renewable and grid electricity without losing the support paid for the renewable power stored in them, and treat bidirectional charging points for electric vehicles in general like storage systems.

Until now, supported renewable electricity and electricity from the grid generally had to be kept apart in a battery. Under MiSpeL a storage system can draw from the grid and feed power back later without losing support eligibility for its renewable share. Electricity drawn from the grid and later fed back is subject to a balancing mechanism, so lower levies and network charges apply to those volumes. The aim is that batteries can respond to prices on both sides, charging when power is cheap and discharging when it is dear.

The rules offer two ways to separate eligible renewable power from grid power. A delineation option, open to everyone, measures the volumes precisely and normally needs two meters, sometimes one. A flat-rate option for households with PV systems up to 30 kW should usually need one meter, but still requires state-aid approval from the European Commission. After criticism in September from carmakers and energy companies that the proposed flat-rate design could hinder bidirectional charging, the agency said the final version makes the simplifications for charging points easier to use. MiSpeL can also be applied to unsubsidised installations and without on-site generation.

Network and metering operators have until the end of September 2027 to implement the rules; in the meantime they can be applied where operators agree. The solar association BSW-Solar called the decision a long-awaited key for using renewable and grid power together in batteries, and storage provider Voltfang pointed to co-location projects that could use existing solar and wind grid connections.

Why it matters

The old separation rule turned many home and commercial batteries into solar-only devices. Allowing them to trade with the grid without losing support is what lets small storage, and eventually parked electric cars, help with exactly the price swings that negative-price hours create.