• credo@lemmy.world
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    4 months ago

    A novel variation on compressed air energy storage that should directly help replace a coal power plant by:

    converting carbon dioxide gas into a compressed liquid form and then converting that liquid back into a gas, powering a turbine to generate electricity, according to the Department of Energy. The gas will be stored in what officials call an “energy dome.”

    From a linked article discussing the proof of concept installation:

    The company says its technology has an energy storage density 10-20 times higher than other compressed air energy storage (CAES) solutions and two-thirds that of liquid air energy storage (LAES). However, Energy Dome points out that its solution does not require the cryogenic temperatures of LAES which can increase system complexity and competitiveness, it claims.

    The DoE adds:

    Through the use of compressed CO2, the system aims to improve efficiency compared to similar systems, as it produces less heat during the compression cycle and can be stored as a liquid. Energy Dome’s modular system also offers flexibility that can support a more resilient power grid.

    Compressed air energy storage currently tops out with round trip efficiencies of 67-71% in complex setups.

    https://www.sciencedirect.com/science/article/pii/S2666202723002045# Search: “Compared to other adiabatic systems”

    https://en.wikipedia.org/wiki/Compressed-air_energy_storage#

  • sin_free_for_00_days
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    4 months ago

    This seems kind of inefficient, but I love all these large-scale energy storage attempts. And these people are a hell of a lot smarter than I am.

  • tunetardis@lemmy.ca
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    4 months ago

    Spent breakfast researching this:

    • the plant would store 200 MWh
    • given the 10-hour figure, one would assume it can feed up to 20 MW to the grid at any time
    • they have already built a 4 MWh pilot plant in Italy
    • the utility has also been building lithium-ion battery farms, so it stands to reason they see enough potential in this approach to continue pursuing it
    • compressed CO2 storage has advantages over compressed air in that it can be stored indefinitely at ambient temperature and has a higher energy density in liquid form
    • it has disadvantages in terms of plant safety
  • mindbleach@sh.itjust.works
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    4 months ago

    Is pumped-hydro inefficient or something? All the arguments about flooding land and surveying geography seem bizarre if the alternative includes a big impermeable structure. We’ve got those, for water. They’re called pools. They’re nontrivial because you have to contain pressure that desperately wants to leak out, but holding compressed air is surely harder. Water also doesn’t change temperature when you move it uphill.

    Why is this better than two reservoirs with a pipeline between them?

      • mindbleach@sh.itjust.works
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        4 months ago

        … what, just anywhere flat? Pumped hydro should be feasible wherever there’s a hill.

        If we’re building big weird structures, even that is optional. You can put one pool above-ground and another in-ground. Deep and tall presumably beat wide.

        • silence7@slrpnk.netOP
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          4 months ago

          To actually do the volumes that make pumped hydro practical you need not just a hill but a space which can hold a truly huge volume of water.

    • DrFuggles@feddit.org
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      4 months ago

      Don’t get me wrong, I love me a good pumped hydro solution, but they do come with a couple of disadvantages:

      a) as others pointed out, you need a somewhat steep gradient between two places. Preferably for a bit of distance so as to increase efficiency by putting more turbines in. Their need for a gradient limits their use in flat locations such as the entire US Midwest, for example.

      b) comparatively expensive and longer construction process than other storage forms.

      c) usually you have to build the upper reservoir. That’s an environmental harm. IMHO not that big if a concern, but it’s there.

      d) if you don’t build out a reservoir, but use an existing lake, you risk contaminating it with algae / cyanobacteria and wreaking havoc on fish and other wildlife.