…Redwood believes that by 2030, end-of-life batteries could supply more than 50 percent of the entire energy storage market. Instead of grinding up used batteries to reclaim the critical materials inside, put them to work storing electricity. There have been many experiments done that re-purpose used EV batteries which no longer can supply enough power to meet the need for rapid acceleration in an EV but still have up to 80 percent of their original energy storage capacity available…

…Traditional energy storage systems are high density and require heavy-duty cooling. To avoid this, Redwood’s team opted for an open-air, low-density system mounted on above-ground cable trays.

Spreading packs out in the open air helps avoid the need for active refrigeration, and stripping away moving parts like fans and filters minimizes potential reliability failures. Keeping the wiring above ground and limiting the size of each modular component minimizes the need for large equipment. As Sun explained, the result is a storage system that is faster to build, easier to inspect after storms, and cheaper to keep running over time…

Not having read the article, I wonder if building an elevated array of photovoltaic panels over the batteries would make sense by shading them from the sun, giving more passive help with heat? A simple roof would be cheaper but solar panels would mean the site is also producing electricity, not just storing it.

They should make "grid modules" like that out of shipping containers - racks of batteries inside with solar panels on the roof. Maybe the panels could be on swing-out hinges to make them able to stow away more compactly for transport on top, and then fold out for more surface area after the module is installed on site

The point of going low density is to reduce cooling requirements. Cramming them into a shipping container is the exact opposite of that.