• Gsus4@lemmy.one
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      1 year ago

      Thought experiment: burn a fuel, now how much energy do you think you have to use to go capture all the CO2 molecules from the air and turn them into a material? At best, you’re going to need twice as much energy to recapture the fuel as what you got from burning it.

      But you say: “the energy to power CO2 capture will come from green sources”. Yes, but these require energy to be produced and you’re encumbering already lower density energy sources than fuel with reversing CO2 debt, when we need those energy sources to power everything else.

      It’s a good way to kick the can down the road and say “we’ll fix it later, when we have lots of cheap energy that we can afford to waste.”

      The answer is, broadly in this order:

      • Don’t cut old forests, these are the best at absorbing CO2 and keeping it in the ground.
      • Minimize forest fires with strategic multi-species tiling, spacing, having grazers eat biofuel
      • Reduce energy consumption through mass transit, home, agricultural and industrial innovation to improve efficiency and reduce waste
      • If you are already not cutting forests, plant trees (takes them centuries to become efficient), grasses and seaweed where adequate (e.g. Scottish highlands) and try to sequester them in swamps, mines or furniture.
      • Move to 100% green energy sources
      • Use emission-neutral vehicles
      • Invent batteries that can store surplus energy for baseload power and shut down nuclear powerplants (if you must…).
      • If there is any surplus green energy left, capture as much concentrated CO2 with algae at CO2-intensive exhausts like natural gas plants and test with artificial methods to see how they compare with plant-based capture.
      • Artificial direct-from air capture with whatever unused energy we have left after all these steps <-------this is this article is right here at the end, once all the other mammoth problems have been solved
      • TALD@lemmy.fmhy.ml
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        1 year ago

        Why aim for shutting down nuclear power plants? The carbon emissions per kwh is the lowest out of all methods we have. Even with solar/wind there’s a carbon cost from the materials and maintenence and from what I remember that cost per kwh is higher than nuclear over a long enough time period.

        • Gsus4@lemmy.one
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          1 year ago

          Fine. Apart from the drama of designing, managing the plant, disposal, storage and guarding of residue, waste of mining and preparing the fuel and being a constant target for assholes (e.g. ZNPP), I have no major problem with nuclear power.

          Comparing with most sources today, it’s one of the cleanest and most reliable, but it’s not much cheaper than wind/solar if you account for the construction/maintenance/safety/insurance/dismantlement costs (last time I checked it was 0.06-0.15 per kWh).

          Still, I placed it really far down in the list, because it’s perfect for baseload power and should be the last of our concerns and the last option we ditch when addressing climate change (looking at you, Merkel).

          PS: on second thought, everybody also vastly underestimates the massive cost of disposing and recycling wind turbines and solar panels…yea :/

          • TALD@lemmy.fmhy.ml
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            1 year ago

            Yeah if we want power at all there’s a heavy carbon cost to it regardless where it comes from. Nuclear from what I understand is more compatible with our preexisting electricity networks because like coal it has big chunks of metal spinning to store energy giving the ability to react incredibly fast to changes in the network. Battery banks may be able to do this quick response, but the longevity of rare earth mineral based solutions although fancy has me concerned. Very little can degrade with a massive flywheel and the losses from nuclear to get it up and spinning would be far lower than say spinning it with motors as an energy store.

            Long term I agree though, the complexities around nuclear don’t paint it as our saviour. Maybe for now, and probably the next hundred years, leaning into nuclear is at least harm reduction

      • coyootje@lemmy.world
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        1 year ago

        Thanks for sharing these, it always makes me feel more optimistic to hear these things, even if using a forest efficiently means that it takes a while for them to get going.

        It sometimes feels like everything is negative nowadays and we’re basically doomed but reading things like these makes me feel like I could make a difference (even if I probably can’t on my own).