Redwood Materials introduces open-air grid storage batteries

Redwood Materials has unveiled an innovative approach to second-life battery storage by deploying open-air battery farms at a pilot site near Reno, Nevada. The company has installed rows of repurposed electric vehicle battery packs on above-ground cable trays, eliminating the need for active cooling systems such as fans or refrigeration. This design not only reduces mechanical complexity and potential points of failure but also simplifies installation by keeping wiring accessible and modular components manageable in size. The pilot project powers four data centres operated by Crusoe, using a 20 MW solar array combined with 12 MWh of repurposed batteries. Redwood intentionally operates the battery packs at a reduced power output compared to their original capacity, prioritising safety, longevity, and thermal management over maximum performance. This strategy enables the system to function effectively even in the hot Nevada climate without requiring energy-intensive cooling, marking a significant step forward in sustainable energy storage solutions. Central to Redwood’s system is a proprietary battery pack management technology that can interface with batteries of varying voltages, protocols, and conditions. This universal adapter converts power into a standard DC output compatible with conventional inverters, while a site controller orchestrates the operation of multiple packs, balancing their state of charge and adjusting usage based on individual pack health. Older batteries are cycled more gently to extend their usable life, while fresher packs are utilised more intensively, reflecting a sophisticated approach to second-life battery management. Following the success of the pilot, Crusoe has committed to installing similar battery storage systems at 20 additional data centres, signalling growing confidence in Redwood’s technology and its potential to scale. The ongoing development of battery health algorithms ensures continuous monitoring and optimisation throughout the batteries’ repurposed lifespan, ultimately feeding back into Redwood’s recycling processes. This initiative highlights a promising model for integrating recycled EV batteries into large-scale energy storage applications, supporting both circular economy goals and renewable energy integration.