• Killing_Spark@feddit.de
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    18 days ago

    For the fun of it I did do the calculation. Berlin uses about 12TWh per year. That’s about 33GWh per day.

    Assuming an energy density of 450Wh/l (a number car batteries apparently were able to reach 2020) that’s about 80.000 m³.

    A soccer field is about 4000 m². So a space of 10 soccer fields with 20m high battery stacks would do that.

    Now assume that energy density will have improved in the last 4,5 years and that maybe storage batteries can be different from batteries in cars and that can go down by a lot. Seems reasonable enough for the biggest city in Germany.

    • PowerCrazy@lemmy.ml
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      18 days ago

      Unfortunately your rough math misses a lot of the picture. This is where the gotcha comes in.

      https://electrek.co/2022/10/19/the-worlds-largest-single-phase-battery-is-now-up-and-running/

      That is a currently realized grid storage facility, the largest and really only one of it’s kind. Today’s renewables do not do storage at all, they rely on fossil fuels to make up the baseload.

      Some numbers. This facility stores 1400MWh, on 2,000 acres or (~8,000,000 sq meters) Much greater then your 40,000sq meter estimate. Plus you said about 33GWh for a day. Well you’d need ~24 of these facilities to cover just Berlin.

      So now the big question, how much energy storage will be needed in a >90% renewable grid? It’s obviously a difficult question based on a lot of factors, but one such estimate I found here: https://www.pv-magazine.com/2022/01/24/us-zero-carbon-future-would-require-6twh-of-energy-storage/ ~6TWhrs for the US or about 4300 of those facilities.

      Yes it wouldn’t have to be monolithic like that facility is, but regardless of how you distribute it, it’s a non-trivial amount of space taken up. Totally ignoring the costs, and sourcing the materials for the batteries of such facilities.

      But just for fun that facility was ~$550M So you’d need to spend about $2.3T for the initial building of that storage.

      • Killing_Spark@feddit.de
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        18 days ago

        Okay so your comparison has a few flaws there. The square meters I calculated were just a reference. The important thing is the volume taken up. If you stack your batteries only 1m high that’s gonna cover a lot of ground. You also completely failed to take into account that energy density has apparently 4x since 2020 which shrinks the required volume significantly.

        I’m gonna argue that 4000 of these facilities distributed around the whole USA isn’t that much. Spacewise the USA is in a very comfortable position compared to European countries.

        As for the price: taking the price for a pilot project and assuming that every facility is going to cost that is very wrong. If you’re going to build 4000 of them, cost is going to go way down.

        But if we are talking numbers here I too have a question. How much land would nuclear plants (and the intermediary storage and final storage for the waste) use to fulfill those 12TWh per year? And how much would those cost to build and maintain? I imagine that a battery facility is way cheaper to operate than a nuclear plant.

        • PowerCrazy@lemmy.ml
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          17 days ago

          You’d be wrong then.
          https://en.wikipedia.org/wiki/Palo_Verde_Nuclear_Generating_Station This is a Nuclear power plant in the middle of a desert so no large bodies of water near by, though obviously the design could be adapted to places where water was more plentiful.

          It takes up 4000 acres (16,000,000 sq meters) Produces (not stores) 4GW (~32,000 GWHrs annually) For comparison, the US Produces 42400000 GWhrs annually. And it cost $14Billion in 2023 dollars

          If I were to replace all of the US’s generating capacity with nuclear, fully shunning renewables. it would cost ~$19Trillion and take up 5.3million acres (which is the minimum amount of land that could be taken up by any currently existing power generation system https://ourworldindata.org/land-use-per-energy-source ). But no one wants to do that (although it would be amazing for the atmosphere). Instead we merely need to supplement renewables with base-load power, and we don’t actually need power storage at all.

          The ideal ratio between renewable power and base-load power I do not know. But during the day in Texas in July it’s about 50% higher then at night. https://www.eia.gov/todayinenergy/detail.php?id=42915

          So even if we assume renewables don’t work at night, base-load only needs to account for ~33% of total electric production at the worst case. Much more manageable then the ~6.5hrs/6TWhrs of energy storage required for a 100% renewable grid to function.

          The tl;dr, is that while renewable powered storage is possible, the magnitude of storage required to eliminate base-load generation is VASTLY larger then anti-nuclear advocates realize, and not feasible today (or possibly ever). This belief stems from is fossil fuel propaganda, especially in Germany where the fossil fuel interests understand they have nothing to fear from renewables because a renewable heavye grid is only possible with fossil fuel plants and every year every nation burns more fossil fuels then they did the year before*, Germany included. It will stay that way until mass famine hits and the human population of the earth collapses, unless we stop burning fossil fuels. The only viable non-fossil fuel replacement for our large and growing baseload capacity is nuclear power.

          *note that fossil fuels aren’t only used for energy production, transportation and shipping are huge areas as well.