Los Angeles is looking into whether it should spend an estimated US$3 billion on a massive, 20-mile underground pumped hydropower storage system that would be connected to the iconic Hoover Dam on the Colorado River outside of Las Vegas. If it does get built, this system would essentially serve as a giant battery to store power. Having written a book about the aggressive propaganda program behind the Hoover Dam’s construction in the 1920s and 1930s, I can say that the technical and financial challenges of this plan are sure to pale in comparison to the legal and political roadblocks that will have to be overcome.