Here's an interesting idea, how about the old electric car batteries get used as long as possible, to support the city electric grid?

A company called B2U, in the Southern California high desert city of Lancaster, has developed a system to use depleted EV car batteries to store 28 megawatt hours of electricity from only three megawatts of solar panels to power the grid when the sun sets. The depleted batteries can be used in that capacity for over five years.

B2U takes depleted EV batteries from Nissan Leafs, Honda’s Clarity, and General Motors and even Tesla batteries, racks them together, and connects them to its big array of solar panels. The solar panels charge the battery packs all day. Then, when the sun goes down and the solar panels can no longer power the electric grid, the old Nissan Leaf batteries discharge their stored electricity onto the grid and B2U sells the electricity to the local utility.

The supply of depleted car batteries is relatively small right now but is doubling every two years, Hill said. As more of the world’s car fleet goes electric, the supply of semi-depleted batteries will grow.

https://www.autoweek.com/news/technology/a43937159/b2u-company-reusing-ev-battery-packs-to-store-solar-energy