What will we do with millions of used electric car batteries

Electric vehicles are widely seen as the key to decarbonising road transport. Despite recent supply chain issues, global electric sales continue to break records every year. The latest figures from the Irish motor industry show that electric surpassed diesel car sales in Ireland for the first time in the first three months of 2023 and represented more than 24% of all new cars sold. The days of the internal combustion engine car are numbered, with last years’ announcement of an EU-wide ban on the sale of new petrol and diesel engine cars by 2035.

But this rapid growth of the electric car market leads to an inevitable question: what will happen to the millions of used electric car batteries in the near future?

It is commonly accepted that an electric car battery’s “second-life” starts when its performance drops to 70 to 75%. While recycling has been proposed as a solution to dealing with end-of-life batteries, the idea of repurposing these batteries for second-life applications is becoming increasingly attractive.

Second-life batteries are retired electric vehicle batteries that still have a considerable amount of capacity left and can be repurposed for various energy storage applications. The second-life battery market is currently in its infancy, but is set for exponential growth. A new “stationary storage systems” sector is emerging, with second-life batteries providing new local and grid-scale energy storage capabilities.

How can we get the most out of electric car batteries?
One of the most promising applications is in stationary energy storage systems designed to support the integration of renewable energy into the electricity grid. Eurostat figures show that Ireland’s renewable energy share in electricity production was 36.4% in 2021, which still lies just below the EU average despite significant progress over the last two decades.