• Victoria@lemmy.blahaj.zone
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    2 months ago

    From a grid stability point, you can’t produce more than is used, else you get higher frequencies and/or voltages until the automatics shut down. It’s already a somewhat frequent occurence in germany for the grid operator to shut down big solar plants during peak hours because they produce way more power than they can dump (because of low demand or the infrastructure limiting transfer to somewhere else)

    Negative prices are the grid operator encouraging more demand so it can balance out the increased production.

    • kippinitreal@lemmy.world
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      2 months ago

      Spot on! I hoped this comment would be higher! The main problem isn’t corps not making money, but grid stability due to unreliability of renewables.

      To be fair, the original tweet is kinda shit to begin with. They’ve unnecessarily assigned monetary value to a purely engineering (physics?) problem.

      • Resonosity@lemmy.world
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        2 months ago

        The original commenter’s (OC’s) point has nothing to do with renewables’ reliability.

        It is entirely to do with generation vs demand. Grid operators could ask other generators like coal, nuclear, hydro, etc. plants to curtail so inverter-based renewables can export power, but that’s not likely because those producers can’t ramp generation up and down as easily.

        Grid stability is a problem when you have overcrowding of generation without enough demand on given feeders. This is moreso an issue with the utilities anyways and how they plan their transmission and substation upgrades.

        • MooDib@lemmy.world
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          2 months ago

          The issue is those coal, nuclear, hydro plants are what produce power when the sun isn’t out. If you consistently shut them down for solar, they will go out of business and there will be no way to provide electricity when solar doesn’t.

    • unexposedhazard@discuss.tchncs.de
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      2 months ago

      But the thing is, you CAN simply turn them off at the press of a button (or an automated script) so its really a complete non issue. As long as big solar installations control systems are accessible by the grid operators, it should be fine.

      • chonglibloodsport@lemmy.world
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        2 months ago

        If you’re spending billions to build a solar plant that has to turn off all the time during peak hours then you’re wasting your money. That seems like a fundamental issue to me, not a non-issue.

        • nilloc@discuss.tchncs.de
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          2 months ago

          Are there any solar plants that cost a billion dollars each?

          Secondly, you want to over build solar, so that you have enough capacity during off peak hours. Grid storage is obviously the better solution, but seems not widely available enough yet.

    • MaxMalRichtig@discuss.tchncs.de
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      2 months ago

      Well I wasn’t expecting to find THE right answer in the comments already. Kudos!

      And to everyone reading through this post: If you have questions, need more explanations or want to learn more about the options that we have to “stabilize” a renewable energy system and make it long term viable, just ask!

        • MaxMalRichtig@discuss.tchncs.de
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          1 month ago

          Well, I set myself up for this, didn’t I… 😅 Actually I was kind of hoping for a more specific question, as I would need to respond with a wall of text - and I would like to avoid that as it is kinda rude to force people to read so much and it makes discussion difficult.

          So maybe 3 options:

          1. Wall of text
          2. You have a more specific question in mind to rephrase
          3. I try to summarize my wall of text, but I might not get the point across
          • thanks_shakey_snake@lemmy.ca
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            1 month ago

            Lol yes you walked right into that one… Well let me try to meet you half way with some open-ended questions:

            1. What does “stabilize” mean in this context, and are the challenges there different than the challenges with non-renewables like fossil fuels?

            2. What are the biggest bottlenecks for stabilizing renewables, and how surmountable are they? For example, I’ve heard lots of talk about how large-scale battery networks(…?) are important to smooth out capacity for swingy energy sources like solar and wind (i.e. you gotta make sure the power doesn’t go out at night!), but the materials for batteries (e.g. extractable lithium?) are scarce… Or similar concerns about photovoltaic cells. Is there any merit to those concerns? Or are the bottlenecks elsewhere? Or is there no bottleneck at all but Big Oil is conspiring to keep us on hydrocarbons?

    • antimongo@lemmy.world
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      2 months ago

      Piggybacking on your grid stability point, another issue I don’t see getting addressed here is ramp rate.

      If we install enough solar where 100% of our daytime load is served by solar, that’s great. But what about when the solar starts to drop off later in the day?

      A/Cs are still running while the sun is setting, the outside air is still hot. People are also getting home from work, and turning on their A/Cs to cool off the house, flipping on their lights, turning on the oven, etc.

      Most grids have their peak power usage after solar has completely dropped off.

      The issue then becomes: how can we serve that load? And you could say “just turn on some gas-fired units, at least most of the day was 100% renewable.”

      But some gas units take literal hours to turn on. And if you’re 100% renewable during the day, you can’t have those gas units already online.

      Grid operators have to leave their gas units online, running as low as they can, while the sun is out. So that when the peak hits, they can ramp up their grid to peak output, without any help from solar.

      There are definitely some interesting solutions to this problem, energy storage, load shifting, and energy efficiency, but these are still in development.

      People expect the lights to turn on when they flip the switch, and wouldn’t be very happy if that wasn’t the case. Grid operators are unable to provide that currently without dispatchable units.

      • Vilian@lemmy.ca
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        2 months ago

        If we install enough solar where 100% of our daytime load is served by solar, that’s great. But what about when the solar starts to drop off later in the day?

        Store the surprus of energy from the solar panels and use that as a buffer with batteries or gravity

        But some gas units take literal hours to turn on. And if you’re 100% renewable during the day, you can’t have those gas units already online.

        Why not? Just time it and start it hours before, wind energy could help in that too

      • Resonosity@lemmy.world
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        2 months ago

        One solution to what you’re describing is to expand the grid. If your grid stretches half the planet, when the East starts to experience night, the West still experiences day and can ship electricity from renewables to the East to make up for their self curtailment. The same goes for wind where if one location on the planet doesn’t experience wind, odds are another location does and the power can be shuffled around.

        Another option is to build out more battery storage such that any clipped energy from solar or wind - that is, the energy that can be generated from your solar or wind resource but that can’t be exported because it would overload your inverters or transformers or exceed your PPA agreement with your utility - is stored and can be exported for 2-4 hours as the sun goes down or wind dies out.

        Not a lot of renewables sites are colocated with battery storage, but more and more are.

    • Mobilityfuture@lemmy.world
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      2 months ago

      As someone with a technical background this is the stupidest problem with solar that I don’t get… just turn off the panels in groups until generation is closer to demand… how have engineers not figured that out. And if they have why does this still get written about.

      Someone is an idiot. Maybe it’s me?

      • antimongo@lemmy.world
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        2 months ago

        I’m adjacent to this problem, so I have a little context, but am not an expert at all.

        To my knowledge, we don’t have granular control over panels. So we can shut off legs of a plant, but that’s a lot of power to be moving all at once.

        Instead, prices are set to encourage commercial customers to intake more power incrementally. This has a smoother result on the grid, less chance of destabilizing.

        A customer like a data center could wait to perform defragmentation or a backup or something until the price of power hits a cheap or negative number.

        • Mobilityfuture@lemmy.world
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          2 months ago

          Thanks that’s helpful.

          But right…?

          Solar plants can be reduced to rationalize supply.

          To my understanding. The bigger issue is you can’t as effectively do this with other non-renewables like coal/gas… so this not a solar problem but a problem of legacy power plants.

          So stupid. The narrative as well.

          • antimongo@lemmy.world
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            2 months ago

            Yea, more control over the panels will help with the overgeneration issue.

            But there’s other issues like ramping supply to meet peak demand and general generation during non-solar hours that still have to be addressed.

            Each have interesting proposals on how to solve them, but they haven’t been developed to the point that they’re ready to be put onto the grid at a large scale.