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Hawaii is in an excellent position to try out the full range of storage technologies and discover which work best for them. They have underground cavities that

by ncmncm 4y ago

Hawaii is in an excellent position to try out the full range of storage technologies and discover which work best for them. They have underground cavities that used to be full of lava, for compressed air, hydrogen storage, or pumped hydro. They have mountains pumped-hydro reservoirs would be easy to build on. They have deep ocean trenches just offshore for undersea compressed air and buoyancy. Choices for renewable generation include not just solar and wind, but also undersea currents and wave air pumping.

tuatoru 4y ago
Volcanic cavities and mountains are not necessarily stable enough and impervious enough to be relied on as reservoirs. Undersea CAES may be worth trying, but I don't know why it hasn't yet been tried.
- ncmncm 4y ago
  Seabed-mounted buoyancy seems to me most promising, but I doubt anybody is working on it.
  - Spinosaurus 4y ago
    What is "Seabed-mounted buoyancy"?
    - ncmncm 4y ago
      Screw a pulley down to the seabed. Run a cable from a float through the pulley to a reel on a winch driven by a motor-generator. (Could be on shore, in a boat anchored out there, or bolted to a wind-turbine post.) Crank the float down toward the seabed when you have power to spare. Let the float reel back out when you need that power back. For extra credit, attach a whole series of reels to one winch, with clutches, so one winch can crank down as many floats as you have reels, one or two at a time. (Floats, pulleys, and reels are cheap, motor-generators expensive, so it pays to share.) Maybe, instead of a winch and clutches, the reels are driven with hydraulics. Size the floats so the winch is a catalog item, say <1000-ton capacity. Use as many motor-generators on winches as you need for the MW you must generate. Use as many pulleys/floats as you need for the MWh you need to store. The deeper the pulleys are, the more MWh each float can store. Keep adding floats until you have enough.

by ncmncm 4y ago

tuatoru 4y ago

Volcanic cavities and mountains are not necessarily stable enough and impervious enough to be relied on as reservoirs. Undersea CAES may be worth trying, but I don't know why it hasn't yet been tried.

ncmncm 4y ago
Seabed-mounted buoyancy seems to me most promising, but I doubt anybody is working on it.
- Spinosaurus 4y ago
  What is "Seabed-mounted buoyancy"?
  - ncmncm 4y ago
    Screw a pulley down to the seabed. Run a cable from a float through the pulley to a reel on a winch driven by a motor-generator. (Could be on shore, in a boat anchored out there, or bolted to a wind-turbine post.) Crank the float down toward the seabed when you have power to spare. Let the float reel back out when you need that power back. For extra credit, attach a whole series of reels to one winch, with clutches, so one winch can crank down as many floats as you have reels, one or two at a time. (Floats, pulleys, and reels are cheap, motor-generators expensive, so it pays to share.) Maybe, instead of a winch and clutches, the reels are driven with hydraulics. Size the floats so the winch is a catalog item, say <1000-ton capacity. Use as many motor-generators on winches as you need for the MW you must generate. Use as many pulleys/floats as you need for the MWh you need to store. The deeper the pulleys are, the more MWh each float can store. Keep adding floats until you have enough.