Rivian and Redwood Materials Deploy 10 MWh of Second-Life

Rivian and Redwood Materials deployed a 10 MWh stationary energy storage system at Rivian’s Normal, Illinois, manufacturing plant, the companies announced on April 14, 2026. The installation uses more than 100 retired Rivian EV battery packs refurbished by Redwood and integrates them into the facility’s grid connection to reduce peak demand charges. The companies describe it as the largest repurposed battery energy storage system deployed at a U.S. automotive manufacturing facility.

How It Works

Redwood Materials collects retired Rivian battery packs – packs that still retain significant capacity but no longer meet EV performance requirements – and integrates them into a stationary storage system using Redwood’s Pack Manager software. The 10 MWh system at Normal dispatches stored energy during the factory’s demand peaks, reducing the 15-minute interval power draws that determine demand charges on Rivian’s utility bill.

Ameren Illinois, which serves the Normal plant, applies a demand ratchet based on the single highest 15-minute peak in any billing month – a structure that can inflate bills for manufacturers with intermittent high-draw operations such as paint shop or chassis stamping. A 10 MWh system can absorb roughly 2-4 hours of peak shaving, depending on plant load shape, and can significantly reduce monthly demand charge exposure if deployed correctly.

Why It Matters

Second-life batteries are entering the grid faster than new stationary cell production can ramp. Redwood estimates that more than 50 GWh of battery capacity will exit U.S. EV fleets before 2030 – enough to supply several years of grid storage demand if effectively re-deployed. The Normal installation demonstrates that second-life systems can be economically competitive with new lithium iron phosphate cells for demand charge reduction applications, where cycle requirements are lower than in daily arbitrage markets.

For Rivian, the partnership reduces demand charge exposure at its largest plant while advancing the company’s circular economy commitments. Redwood Materials gains a recurring supply of packs for its refurbishment pipeline, replacing an ad-hoc parts stream with a structured partnership with a named automaker. The model could extend to Rivian’s planned Georgia plant and to other automakers with established EV fleets.

Critical Perspective

Second-life batteries carry capacity uncertainty: individual packs vary in remaining state of health, and degradation curves for automotive cells in stationary cycling duty are not fully characterized at commercial scale. Redwood’s Pack Manager software manages cell-level monitoring to flag degraded units, but warranty terms for second-life systems are typically shorter than for new BESS installations. Whether Ameren Illinois will grant demand response enrollment to a second-life system – and at what reliability standard – is not addressed in the partnership announcement.

Sources

• https://www.businesswire.com/news/home/20260414701719/en/Rivian-and-Redwood-Materials-Announce-Energy-Storage-Partnership-for-Manufacturing
• https://electrek.co/2026/04/14/rivian-redwood-materials-energy-storage-partnership-illinois/
• https://chargedevs.com/newswire/rivian-and-redwood-deploy-10-mwh-of-second-life-battery-storage-at-illinois-factory/

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