There is also the idea of gravity pistons which claim to have the advantage of a much wider allowance of siting options than pumped hydro. https://heindl-energ

There is also the idea of gravity pistons which claim to have the advantage of a much wider allowance of siting options than pumped hydro. https://heindl-energy.com/ https://heindl-energy.com/ Nice long-form discussion with the Omega Tau podcast: http://omegataupodcast.net/299-gravity-storage/ http://omegataupodcast.net/299-gravity-storage/ Also this: (don't know if there is any association) http://www.gravitypower.net/technology-gravity-power-energy-storage/ http://www.gravitypower.net/technology-gravity-power-energy-...