TREASoURcE, an EU-funded research initiative, has examined whether end-of-life electric vehicle (EV) batteries can be repurposed for stationary energy storage, highlighting both the technical feasibility and the remaining barriers to large-scale deployment.
According to the TREASoURcE project, by the end of 2025 there were nearly 8.5 million battery electric vehicles across Europe, spanning passenger cars, vans, trucks and buses. Collectively, these batteries represent hundreds of gigawatt hours of installed capacity – equivalent to around 1.5 hours of total electricity consumption across the whole of Europe.
The project found that a significant proportion of this capacity remains usable once vehicles reach the end of their automotive life. Typically, lithium-ion batteries are retired from vehicles when their state of health falls to around 70–80%, at which point reduced driving range affects resale value. However, these batteries can still be suitable for less demanding stationary applications such as battery energy storage systems (BESS).
TREASoURcE pilot installations
Pilot installations in Norway and at Lempäälä House in Finland demonstrated the concept in practice, with the Norwegian sites proving more suitable for continued operation. Discussions are ongoing to extend their use beyond the project.
The study concluded that reuse can offer both environmental and economic advantages over immediate recycling. Extending battery life reduces demand for virgin raw materials and provides a relatively low-cost route to supporting renewable energy integration.
However, the project also identified significant technical and commercial constraints. Battery chemistry plays a key role: nickel-manganese-cobalt (NMC) batteries may be more valuable as a source of recoverable materials, while lithium iron phosphate (LFP) batteries could be better suited to second-life applications.
“Reuse is clearly more successful if the original Battery Management System, or BMS, can be used. This is properly successful if the battery’s original manufacturer permits the reuse solution provider to use the BMS”, said Raimo Tengvall, senior specialist at Forum Virium Helsinki.
Reliable testing of remaining capacity and internal resistance is also essential prior to reuse, with the project calling for standardised testing protocols and improved access to battery data, including charging histories.
Operational considerations were also highlighted during the trials. “A battery as an energy storage unit is best suited for sites with an occasional large power requirement: public events, industrial processes, or even high-power charging for electric vehicles”, Tengvall said.
Safety remains a key concern, particularly given the increased risk of failure or thermal runaway in aged batteries. Installations require grid connection approval, fire suppression systems and site-specific safety assessments, as dedicated regulations for battery rooms are not yet established.
In the near future, regulatory developments such as the EU Battery Regulation’s Digital Product Passport – due to be introduced in 2027 – are expected to improve traceability and facilitate reuse. However, meaningful volumes of suitable batteries are unlikely to emerge until the 2030s and 2040s.
The project also noted that low prices for new batteries, combined with labour-intensive repurposing processes and restricted access to proprietary battery management systems, continue to limit commercial viability.
“If processes can be standardised, used electric vehicle batteries could become one part of a flexible energy system – alongside new batteries and other energy storage solutions”, Tengvall concluded.
The EU-funded TREASoURcE project aims to develop the circular economy across the Nordic countries, the Baltics, Germany and Poland. Its Replication Handbook website compiles the functional results and operating models from the project including information on plastic recycling and using bioeconomy side streams, as well as batteries. Forum Virium Helsinki is the City of Helsinki’s innovation company.
Main picture: an AI-generated image of a group of end-of-life vehicles being used as BESS Credit: Shutterstock
