Electric vehicle (EV) batteries are not just for powering cars anymore. A new study suggests that these used batteries could play a significant role in meeting China’s grid storage needs, helping to balance the supply and demand of electricity from renewable sources.
Renewable energy generation, such as wind and solar power, can fluctuate based on environmental conditions. This variability can lead to shortages during peak demand times, like mornings, evenings, and winter months. Traditionally, gas and coal plants have filled this gap. However, countries like China, the US, the UK, and Australia are turning to grid storage solutions using batteries to store excess renewable energy for later use.
Researchers at Tsinghua University in China propose that as EVs become more prevalent, dismantled car batteries could be repurposed for grid storage. These “second-life” batteries, which are typically retired when they reach about 80% of their original capacity, could potentially meet 67% of China’s grid storage demand by 2050. Not only would this approach help reduce costs by 2.5%, but it could also accelerate the transition to a carbon-neutral power system.
While EV batteries degrade over time with use, this degradation has minimal impact on grid storage systems. Hundreds or thousands of batteries can be used collectively to store and release electricity over extended periods. This approach not only maximizes the remaining power capacity of these batteries but also promotes sustainability by reducing waste.
Although some studies have debated the cost-effectiveness of using used batteries for energy storage compared to new lithium-ion batteries, the increasing number of EVs on the road suggests that second-life batteries could become more economical in the future. With millions of EVs being purchased each year, especially in countries like China, a significant supply of used batteries will be available for repurposing.
The study envisions a scenario where different battery chemistries are sourced nationwide in China and deployed until they reach 40% of their original capacity. This approach could result in a rapid growth of second-life grid storage capacity after 2030, surpassing the capacity of new batteries and pumped hydro storage. By 2050, total capacity could reach 2 trillion watts, providing a reliable and sustainable energy storage solution.
While the concept of second-life battery storage is promising, it does come with challenges. Used batteries must be carefully screened, grouped based on capacity, and equipped with safety features like temperature and voltage sensors to prevent potential hazards like overheating. Despite these challenges, companies like Redwood Materials in the US have already demonstrated the feasibility of using decade-old car batteries for grid storage projects.
As the world transitions towards a cleaner and more sustainable energy future, the potential of repurposing used EV batteries for grid storage offers a cost-effective and environmentally friendly solution. By harnessing the remaining power capacity of these batteries, countries can accelerate their transition to renewable energy sources while reducing waste and promoting sustainability.
