• ChaoticNeutralCzech@feddit.org
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    2 months ago

    There is a lot of operations that aren’t timing-critical (their work is cumulative) and can be made cheaper by only using excess energy in daytime.

    • Pumped hydro
    • Charging grid-tied batteries and EVs
    • Air heating/conditioning (especially when used with physical heat storage)
    • Water heating/cooling for residential use
    • Water heating for pools
    • Reverse osmosis
    • Furnaces in glass/metal/aluminum factories, crematoriums etc.
    • Computation-heavy tasks (AI training, simulations, rendering, crypto mining…)

    Solar can be built wherever there’s demand for any of these, right? Also, more customers should adopt a real-time energy pricing model.

    • frank@sopuli.xyz
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      2 months ago

      I will say, from my time being a process engineer in metals:

      -Everything runs 24/7 cuz the equipment is so expensive and there’s always too much demand

      -furnaces are gas, probably too hot to reach in a reasonable space with electricity

      Totally agree with storing temperature/water locally as a battery, especially at home levels

      • wewbull@feddit.uk
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        2 months ago

        I believe the electric funaces are called "Arc furnaces" and you heat by making electricy jump between conductors.

        One of the advantages over blust furnaces is that production can be varied more easily as there isn’t a whole lot of ancillary parts of the furnance which all need to get up to temperature. So only running them on excess energy might be more practical.

        • frank@sopuli.xyz
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          2 months ago

          Oh I wasn’t even thinking of it, but for secondary in iron that is probably perfect. Still not gonna be able to continuously anneal or anything due to the massive amount of thermal mass needed, but for the “spot” stuff that sounds perfect

          I also have no idea about titanium production and it could easily be useful there

    • evasive_chimpanzee@lemmy.world
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      2 months ago

      Yeah, this should really be the future. There’s a lot of unnecessary materials used/energy wasted to give us our current “all power costs the same all the time” system.

      According to this, about 70% of US household energy use is heating/cooling the space, or water. Much of that can be time shifted. What can’t be time shifted can be stored in cheaper ways than battery storage.

      1 tonne of rock heated (or cooled) 20° C above ambient is a store of about 4.7 kWh. According to that same site, the average yearly energy use in the US is 10500 kWh. If 70% is heating/cooling, that’s about 20 kWh per day, so you’d need about 5 tonnes of rock to hold that enough energy. That seems like a lot, but it’s just about 2 cubic meters of rock.

      If you use water, it has 5 times the specific heat (but less density), so you only need 1 cubic meter. Probably easier to heat/cool/use, too. Water can also be heated more than 20 degrees above ambient, too.

      Really, we should create incentives for homes to be built with high thermal mass. Even without any sort of fancy direct heating or cooling of a thermal mass, it will store significant heat.

      • Logi@lemmy.world
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        2 months ago

        Really, we should create incentives for homes to be built with high thermal mass. Even without any sort of fancy direct heating or cooling of a thermal mass, it will store significant heat.

        Welcome to traditional housing in Italy and probably elsewhere in the Mediterranean region. Thick stone walls even out the temperature swings through the day. Throw open the windows when the temperature is comfortable and close up when it gets too hot or cold depending on the season. This gets you quite far without any air-conditioning or heating.

      • vzq@lemmy.blahaj.zone
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        2 months ago

        If you use water, it has 5 times the specific heat (but less density), so you only need 1 cubic meter. Probably easier to heat/cool/use, too. Water can also be heated more than 20 degrees above ambient, too.

        My old house had an electric boiler that would automatically heat up at night when electricity was cheap. They have fallen out of fashion in the past two decades or so around here, but I can see them making a come back.

        Of course that was direct resistive heating. Stick a heat pump in there and you got something.

      • Valmond@lemmy.world
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        2 months ago

        Wait until you calculate how much energy you need to tip over to the freezing point for water!

        • evasive_chimpanzee@lemmy.world
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          2 months ago

          Yeah, freezing water is definitely great. It’s just a little trickier to deal with since you need to account for the expansion, and the fact that you can’t pump it around anymore.

    • Hirom@beehaw.org
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      2 months ago

      That’s true. If there’s lots of flexibility in the energy consumption, then it would be easy to keep adding lots of renewable. And there’s lot of potential for demand flexibility.

      In reality there’s limited flexibility, in part due to laziness and inertia. So adding more solar is giving diminishing returns. Which means adding solar gets harder to do economically as the share of renewable increase.

      There need to be better incentives for flexibility in demand (ie push consumer to shift energy usage) and for storage (ie give energy producers bonuses depending on the amount of energy storage they have available).

    • general_kitten@sopuli.xyz
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      2 months ago

      Factories often kinda have to run 24/7 so only firing up the furnaces/other electricity intensive machines when electricity is cheap isn’t feasible in most cases

      • ChaoticNeutralCzech@feddit.org
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        2 months ago

        I’m not saying factories should be forced to switch machinery like with ripple control systems in Soviet countries (contactors in households and industry switching based on signals superimposed on the 50Hz grid), there should just be an appropriate economic incentive in doing so. If it’s not enough to offset equipment cost, the factories can ignore it.