Form Energy, a startup from Massachusetts, has developed an iron-air battery for long duration energy storage, surpassing Tesla's Megapack 3 in terms of duration. The company secured a 300-megawatt, 100-hour energy storage deal with Xcel Energy and Google, aiming to provide cost-effective, safe, and reliable energy storage solutions for a grid saturated with wind and solar power. Xcel Energy is moving forward with plans to deploy a Form iron-air battery in its energy plan for a new Google data center in Minnesota, pending approval from the Minnesota Public Utilities Commission. The technology involves iron pellets that rust when exposed to air, releasing energy, and can be recharged by applying electricity, with Form Energy receiving funding to establish a factory in West Virginia for mass production of their iron-air batteries.