Meta and Google are pouring billions into long-duration batteries to keep AI running

Meta and Google are placing major bets on long-duration energy storage systems, the kind that can keep power flowing for days instead of hours, as they scramble to find enough clean electricity to feed their ballooning data center empires. Standard lithium-ion batteries typically discharge for around four hours. The new wave of investments targets systems capable of 10 to over 100 hours of continuous discharge, a fundamentally different class of energy infrastructure. The deals on the table Google’s February 2026 agreement with Form Energy stands out as the marquee transaction. The deal covers a 300 MW / 30 GWh iron-air battery system slated for a Minnesota data center, reportedly the world’s largest by energy capacity. The project carries an estimated price tag of around $1 billion and promises 100-hour discharge capability. Iron-air batteries work by essentially rusting iron to store energy and then reversing the process to release it. They’re far cheaper per kilowatt-hour than lithium-ion at long durations, though they’re bulkier and slower to respond. In September 2026, Google partnered with MN8 Energy on what’s being called the Mammoth Solar project. That initiative combines 8...