• KillingTimeItself@lemmy.dbzer0.com
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    10 days ago

    solar cells have no mechanically moving parts

    ironically, large grid tie systems are starting to “emulate” the spinning mass behavior of turbine generators, since there’s an exponential failure issue waiting to crop up if you aren’t careful, as texas has already learned, a very significant part of your solar generation can just, go offline, if it decides grid conditions aren’t suitable, which can lead to LARGE drops in power production and frequency, which is likely to kill even more generation.

    So the solution is to make it emulate the physical mass tied to a turbine, or at least, more generously provide power in fault like conditions, to prevent this sort of exponential breakdown of the grid. You could of course, use a large spinning flywheel to regulate grid frequency, as is being used in a few places right now. I’m not sure how popular that is, outside of wind energy. It’s likely to get more popular though.

    weird little side tangent, but the frequency of electricity on the grid is essentially directly tied to the rotational speed of all turbines currently on the grid, meaning there is a very large inertia in the grid frequency, it’s weird to think about, but makes perfect sense, and it provides for an interesting problem to solve at large scales like this.

    Batteries are really fucking cool btw, the fact that you can just chemically store electricity, and then use it, is really fucking crazy. The fact that it’s the most accessible technology is also insane to me. But maybe it’s just the adoption being the way it is.

    • TheOakTree@lemm.ee
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      10 days ago

      I think people underestimate the value of intertia in power generation. I liken it to the way capacitors regulate voltage changes or coilovers absorb bumps and vibrations.

      The inertia of the generators connected to the grid helps stabilize frequency changes caused by blackouts, power plant issues, etc. by resisting and thereby slowing down frequency decline. It buys time for grid operators to find a way to balance loads in a way that doesn’t weaken or disable the grid as a whole.

      Here’s a great NREL report explaining how this all works, and what other systems we use to stabilize grid frequency.

      • KillingTimeItself@lemmy.dbzer0.com
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        9 days ago

        I think people underestimate the value of intertia in power generation. I liken it to the way capacitors regulate voltage changes or coilovers absorb bumps and vibrations.

        the best way to think about it is a literal flywheel, because that’s what this is, just at a grid scale, and directly tied to the frequency.

        The inertia of the generators connected to the grid helps stabilize frequency changes caused by blackouts, power plant issues, etc. by resisting and thereby slowing down frequency decline. It buys time for grid operators to find a way to balance loads in a way that doesn’t weaken or disable the grid as a whole.

        TLDR it moves the “OH SHIT OH FUCK” window from about < 1ms worth of time in the worst cases, to the much more manageable, seconds window.

        It’s a potential challenge with moving to renewables, but not a significant one, i think. This is also a big advantage to having sources based on thermal generation, like nuclear.

    • MentallyExhausted@reddthat.com
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      10 days ago

      Also, solar trackers are a big deal for large farms when you start to scale above residential. Those trackers physically moving the panels to optimize generation are moving pieces.

      • KillingTimeItself@lemmy.dbzer0.com
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        9 days ago

        this is sort of true, it depends on the array, but from what i understand, unless you’re doing an experimental array, it’s most common to just use fixed axis mounted panels, it’s much cheaper and more cost effective that way. Ideally you would use a tracking array, which is better, but more complicated, and requires significantly more maintenance and investment. Single axis tracking arrays might be a clever solution to this problem though.

        Regardless, it’s not relevant to the grid inertia problem at hand.