A car mechanic named Jeff Carpoff invented a portable solar generator. Companies like Geico and Progressive Insurance bought thousands of his generators because they got tax credits for doing so. But there was something not quite right about Carpoff’s invention. You can read Ariel Saber’s Atlantic story, “The Billion Dollar Ponzi Scheme that hooked Warren Buffett and the US Treasury,” here: https://www.theatlantic.com/magazine/archive/2023/06/dc-solar-power-ponzi-scheme-scandal/673782/