This week, a visit to the energy startup trying to replace coal with a very cheap battery. Form Energy has attracted nearly $900 million in investments and is building its first manufacturing facility in the US. Its big innovation relies on rust. Really. The materials scientists at Form have taken the same process that’s a symbol of time slowly passing and turned it into electricity. It’s one of the first big bets that batteries could help push the grid closer to running without fossil fuels altogether. You can read more about Form Energy and see what the battery looks like here. Read a transcript of this episode, here.Zero is a production of Bloomberg Green. Our producer is Oscar Boyd and our senior producer is Christine Driscoll. Special Thanks to Kira Bindrim and Blake Maples.  Thoughts or suggestions? Email us at [email protected]. For more coverage of climate change and solutions, visit https://www.bloomberg.com/green See omnystudio.com/listener for privacy information.