Earlier this was for a much larger cylinder, say kilometers across, where you could leave the nature at the top intact. They have explanation here. http://www.

Earlier this was for a much larger cylinder, say kilometers across, where you could leave the nature at the top intact. They have explanation here. http://www.authorstream.com/Presentation/heindl-958931-hydraulic-energy-store-system/ http://www.authorstream.com/Presentation/heindl-958931-hydra... (Edited to change info it was the same guy, added url)