With the number of electric vehicles hitting the market increasing, so the question of what becomes of the used batteries arises. While recycling seems to be the default option, these batteries could play a substantial role in the electricity grid for demand response and frequency regulation
Utilities look for energy storage systems that will last 10-15 years. GM estimates that the current Volt battery still retains about 70% of their capacity after being replaced by their owners after about 10 years of use. A 30% drop in capacity would not be feasible for an electric vehicle as the car would need to be recharged more often. However, this remaining capacity could well contribute to residential solar/storage combinations and/or provide reliability to the grid.
Sumitomo launched a pilot project last year to explore the commercial viability of an energy storage system made from used EV batteries. Separately, BMW has also partnered with the company Vattenfall to develop secondary uses for EV batteries and GM has developed a used EV battery microgrid backup system with the global company ABB.
What these companies will now have to do is work out a mix of used batteries to deliver the ideal performance for grid storage, to store and discharge power over many cycles.
To make this economically feasible, there have been suggestions for cost-sharing of batteries between carmakers and grid storage companies that correspond to the capacity used.
If you want to know more about this and other topics directly from end users of energy storage technologies join us at one of these annual events: The Energy Storage World Forum (Grid Scale Applications), or The Residential Energy Storage Forum, or one of our Training Courses.