Comment on Anon questions our energy sector

• iii@mander.xyz ⁨4⁩ ⁨weeks⁩ ago

  Source (1)

  Later this month the LA Board of Water and Power Commissioners is expected to approve a 25-year contract that will serve 7 percent of the city’s electricity demand at 1.997¢/kwh for solar energy and 1.3¢ for power from batteries.

  The project is 1 GW of solar, 500MW of storage. They don’t specify storage capacity (MWh). The source provides two contradicting statements towards their ability to provide stable supply: (a)

  “The solar is inherently variable, and the battery is able to take a portion of that solar from that facility, the portion that’s variable, which is usually the top tend of it, take all of that, strip that off and then store it into the battery, so the facility can provide a constant output to the grid”

  And (b)

  The Eland Project will not rid Los Angeles of natural gas, however. The city will still depend on gas and hydro to supply its overnight power.

  Source (2) researches “Levelized cost of energy”, a term they define as

  Comparative LCOE analysis for various generation technologies on a $/MWh basis, including sensitivities for U.S. federal tax subsidies, fuel prices, carbon pricing and cost of capital

  It looks at the cost of power generation. Nowhere does it state the cost of reaching 90% uptime with renewables + battery. Or 99% uptime with renewables + battery. The document doesn’t mention uptime, at all. Only generation, independant of demand.

  To the best of my understanding, these sources don’t support the claim that renewables + battery storage are costeffective technologies for a balanced electric grid.

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  • Blue_Morpho@lemmy.world ⁨4⁩ ⁨weeks⁩ ago

    It looks at the cost of power generation

    Yes.

    But then you added the requirement of 90% uptime which is isn’t how a grid works. For example a coal generator only has 85% uptime yet your power isn’t out 4 hours a day every day.

    Nuclear reactors are out of service every 18-24 months for refueling. Yet you don’t lose power for days because the plant has typically two reactors and the grid is designed for those outages.

    So the only issue is cost per megawatt. You need 2 reactors for nuclear to be reliable. That’s part of the cost. You need extra bess to be reliable. That’s part of the cost.

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    • iii@mander.xyz ⁨4⁩ ⁨weeks⁩ ago

      But then you added the requirement of 90% uptime which is isn’t how a grid works.

      I’m referring to the uptime of the grid. Not an individual power source.

      We’ve successfully banned fossil fuels and nuclear, as is the goal of the green parties

      How much renewable production, and bess, does one need to achieve 90% grid uptime? Or 99% grid uptime?

      If it’s just 90%, I can see solar + bess beating nuclear, price wise. If the goal instead is a reliable grid, then not.

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      • Blue_Morpho@lemmy.world ⁨4⁩ ⁨weeks⁩ ago

        Yes you have to build for worst case. That’s what I already said.

        You are comparing overbuilt nuclear but acting like bess can’t be over built too. That’s why the cost of storage is the only important metric.

        You need an absolute minimum of 2 nuclear reactors to be reliable (Belgium has 7). That doubles the cost of nuclear. But it doesn’t matter because that’s factored in when you look at levelized cost. You look at cost per MWhr. How reliability is achieved doesn’t matter.

        Bess is $200 per MWhr.

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      • Ooops@feddit.org ⁨4⁩ ⁨weeks⁩ ago

        How much renewable production, and bess, does one need to achieve 90% grid uptime? Or 99% grid uptime?

        About 115% to 130%. Depending on diversification of renewable sources and locations. The remains are losses in storage and transport obviously.

        But shouldn’t you actual question be: How much storage is needed?

        For a quick summary of those questions you can look [here](file:///tmp/mozilla_daniel0/Fraunhofer-ISE-Study-Paths-to-a-Climate-Neutral-Energy-System-1.pdf) for example…

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