‘World’s largest battery’ to help run Google’s new clean energy data center

Google announced plans to build a new data center in Pine Island, Minnesota, powered by 1.9 gigawatts of clean energy from wind and solar sources. Central to this initiative is a 300-megawatt iron-air battery system developed by Form Energy, claimed to be the "world’s largest" with a 30-gigawatt-hour capacity and 100-hour duration. This long-duration battery technology differs from conventional lithium-ion batteries by storing energy through reversible iron rusting, enabling the data center to operate on clean energy for extended periods, including nights or low-generation times. Although less efficient than lithium-ion batteries (50-70% vs. over 90% energy return), Form’s batteries are significantly cheaper, costing about $20 per kilowatt-hour, roughly a third of lithium-ion costs. The project also introduces an innovative utility fee system in Minnesota called the Clean Energy Accelerator Charge (CEAC), designed to help utilities invest in clean energy without conflicting with regulatory preferences for low