Redwood Materials, a startup founded by former Tesla CTO JB Straubel that recycles more than 70% of all the batteries in North America, proposes repurposing old electric vehicle batteries to store electricity for the power grid, factories, and AI data centers. The company cites projections that AI data centers alone could consume 12% of US electricity by 2028, adding pressure to a grid facing rising demand from electrification and factory reshoring. Building new transmission lines takes years, so large battery storage systems can balance supply and demand in the interim. Redwood argues that more than 6 million electric vehicles sold in the US over the past decade provide an overlooked source of batteries, as aging packs that no longer offer sufficient driving range could still store electricity. The company estimates roughly 1 terawatt-hour, or 1,000 gigawatt-hours, of used EV battery capacity will become available in the US by 2040, and beginning in the early 2030s, these second-life batteries could supply about half of the country's energy storage demand during that period. Redwood aims to provide about 400 gigawatt-hours of this supply, developing technology to combine battery packs from more than 100 different EV models into standardized storage systems. Batteries that cannot be safely reused would be recycled to recover materials such as lithium, copper, and rare earth minerals, potentially creating lower-cost storage while keeping materials inside US supply chains.