German startup Eden Energy has delivered its first commercial battery storage system, a 70 kWh unit built from 112 retired e-scooter batteries. The Freiburg-based company is a spin-off from the Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) and is developing systems that give used micromobility batteries a second life in stationary storage.
The company is initially targeting small and medium-sized businesses that have photovoltaic systems but no battery storage. Eden Energy says the systems could also help municipal utilities increase self-consumption, reduce peak demand and support electricity trading.
Eden Energy’s approach uses power electronics developed at Fraunhofer ISE to connect different storage units and enable communication between modules without dismantling the battery packs. The first system’s batteries were screened before installation. The startup currently sources them mainly from large e-bike and e-scooter fleet operators, which can provide sufficient quantities of matching battery types.
Tests on 350 batteries found that some retained well over 90% of their original capacity. Eden Energy had expected them to retain around 80%. The company says stationary use could expose the batteries to less vibration and fewer temperature fluctuations than mobile applications.
The system is designed to allow individual modules to be replaced while it remains operational. Eden Energy monitors modules with a tracking system and sends them to partner companies for recycling when they reach the end of their service life. The company says replacing modules can help maintain the system’s storage capacity over time.
Eden Energy plans to scale its systems to capacities of up to 300 kWh and is seeking additional commercial pilot customers in the region. Businesses participating in the state-funded “Mittelstand trifft Start-ups” program can receive a subsidy covering 50% of the cost of an Eden Energy storage system.
The company says around one million high-performance e-bike and e-scooter batteries are discarded in Germany each year, although many retain substantial capacity. Wider use in stationary storage remains challenging because of differences in battery designs, cells and management systems. Eden Energy expects its technology to support different battery types in the future, but this will require adaptations to connectors, management systems and communication protocols.
Sources: pv magazine.