New Role for Old Car Batteries

A way of keeping these units from landfill is to use them as Battery Energy Storage Systems (BESS)

As EVs become familiar sights on our roads, we are faced with the tricky issue of what to do with the batteries when they are wearing out and no longer generating enough electricity for car use. Once it has reached the end of its service life in the vehicle, this energy storage unit could be still working at up to 80 per cent of its original energy storage capacity. It isn't sensible to send an expensive battery for recycling when it can still be used productively. The battery can be reused and start a long second life – as a stationary storage unit. According to some estimates, these batteries might be able to operate efficiently in stationary storage facilities for at least another ten years.

This improves the CO2 footprint and material efficiency of the battery. It could also provide extra income for the owner, who has a range of options for re-using the energy storage unit before it eventually wears out and needs to be recycled.

Over the next ten years, as the number of batteries formerly used in electric cars increases, there will also be many more options for second-life batteries. Analysis by IDTEchEx suggests that by 2029, three million battery packs that were previously used in electric vehicles – with a combined storage capacity of 100 GWh – will become available each year.

An example of the reuse of old car batteries is the UK's Advanced Manufacturing and Research Center (AMRC) North West in the North of England. It has solar panels on the roof, and it is using old Renault car batteries as its BESS. This ensures that the center has energy available when it needs it. Opened in 2022, it is one of a number of centers devoted to advanced research run by the University of Sheffield.

Many industrial buildings have unused roof space they could utilize for PV systems, but ideally these should be partnered with battery storage: if there is an excess of energy, it will just be wasted unless it can be captured for time-shifted usage. Most businesses have been hard hit by the volatile prices of energy recently, and by generating their own electricity first, it will help alleviate this issue. Again, many businesses are transitioning to electric vehicle fleets so will inevitably have surplus batteries on hand in future.

The benefits are various: improved energy efficiency, reduced emissions, control of energy costs, use of local generation and VPPs, not to mention Environmental, Social and Governance (ESG) improvements. Many companies now have ESG targets, so this will help them meet those goals.

In addition, battery storage projects can help improve the speed, efficiency and cost-effectiveness of the process of integrating much more renewable energy into the grid, which is moving towards 40 to 45% of the energy mix in some countries. Utility-scale stationary storage facilities are the key to stabilizing the power grid when there are weather-related fluctuations in the quantities of wind and solar energy that can be generated. In the next ten years, electric vehicles will introduce five to ten times more storage capacity to the market than all of the pumped-storage power plants put together.

So up-cycling old car batteries is going to be an additional benefit to the future of electricity generation by improving energy efficiency and storage.