3 ms·

How do they make the seal at the bottom of the piston?

• ec109685 8y ago
  “The Gravity Storage is cut out of surrounding rocks. Because rocks nearly always have crevasses and fine cracks through which water can flow, it is necessary to completely seal the piston and the surrounding piston cylinder against the surrounding area. For this purpose, all freely exposed surfaces are sealed with a geomembrane and concrete.”
  • ISL 8y ago
    There still needs to be the equivalent of a series of O-rings between the piston and the cylinder bore to prevent the piston from sinking. I'd guess that it is the second-hardest technical problem, after the considerable challenge of isolating the piston.
    • gns24 8y ago
      The 'rolling membrane' that they are proposing is described here: https://heindl-energy.com/technical-concept/engineering-challenges/ https://heindl-energy.com/technical-concept/engineering-chal...