This is cool. What size of gravity battery would you need for a typical solar powered American home? One of the obstacles to solar power and a decentralized power grid is of course battery storage for power when the sun is not out. A cheaper and environmentally more friendly battery system could revolutionize the decentralizing of world electric power. It would also create a lot of jobs for installation and maintenance. Our solar panels generate enough power for our home but batteries would be too costly to add. So we remain connected to and obliged to a power company. I would love to change the power dynamic in that relationship!