The increase in the number of electric vehicles means there will be a lot of batteries. Some of these batteries may complete their lifecycle with the life of the vehicle, and some may go out early, and that means we will have a lot of batteries to deal with in the future. Recycling, of course sounds like a very viable option, but why recycle when you can reuse?
Even when a battery pack is unfit for vehicle powering duties, it can still hold nearly 80% of its charge. This could make the batteries an intermittent power source for solar farms as well as wind farms. They can store any surplus power generated, and feed it back when need arises, as in low wind and/or cloudy conditions.
Solar and wind farms do face the problem of dealing with surplus energy generated, and while not entirely a solution, batteries could be helpful. Also, it would drive down costs as vehicle manufacturers could provide batteries on lease to customers, and later hand them over to utilities.