• Wanderer@lemm.ee
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    2 days ago

    Just to be clear this can’t be solved with storage. Currently it can be but not permanently.

    For ease of argument let’s say the grid runs 100% on solar with batteries that last a day. For 100% solar you need to build power for when demand is highest, winter, and supply is lowest also winter. Come summer demand is lowest and supply is highest. You can’t store all that energy in summer because you got fuck all to do with it.

    It’s a really weird cost saving exercise but basically when supply is massively abundant it has to be wasted. No one is going to build that final battery that is only used for 1 day every 10 years.

    Bringing it all together. In a 100% renewables grid with solar, wind, hydro and batteries a lot of electricity will be wasted and it will be the cheapest way to do it. Cheaper than now.

    Quite a few people talk about this on youtube. Tony Seba and rethinkx is the best place to start in my opinion.

    • humanspiral@lemmy.ca
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      1 day ago

      You can’t store all that energy in summer because you got fuck all to do with it.

      Main value of H2 electrolysis is solving (more economic return from renewables than just curtailing) this problem. Also provides exportable energy to cover winter clean power/heat needs.

      • Wanderer@lemm.ee
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        1 day ago

        I’ll be interested to see what happens with this.

        New forms of industry will work out if you got very low capital costs and high energy costs. The factory is going to be running, what? At most 25% of the year? Probably more like under 10 and unpredictable. That’s going to be so weird for profitability.

        I feel like storing the hydrogen itself could be an issue. Storing methane seems way easier so I wonder if that happens instead. But is it cheap to make a device that can make huge amount of hydrogen or methane? I have no idea and no one seems to know what’s going to happen yet.

        I just expect most of it to be dumped. Because it’s 1 less thing to buy.

        • humanspiral@lemmy.ca
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          23 hours ago

          To get $2/kg 300 bar H2, $500/kw electrolyzer capital costs, and 2c/kwh electricity input costs are needed. China is pushing down to $300/kw on electrolyzer costs. Just as seasonal negative prices happen in some locations, stabilizing to 2c/kwh is the path H2 enables. $2/kg H2 means 6c/kwh CHP power cost from Fuel Cell, and 10c/kwh electric only power output. Competitive with electric utility service, and fast charging vehicle stations. It’s competitive at $4/kg in many jurisdictions, in fact.

          Factories already operate mostly daytime. Solar output is seasonal with more variability the further from equator you go. Having solar cover 100% of summer cloudy day generation at low AC use, can result in 2c/kwh or less prices on sunny days, and in Spring and fall where there is no HVAC demand. Running FF electricity just in winter/backup is path to significantly lower emissions, and lower cost of FF energy from less use. Factories with long shifts running half on solar is still low overall energy input costs, if they can sell what they make.

          H2 storage is a solved problem. Lined pipe and pressure vessels. If factories are ever automated to the point where labour cost is nearly irrelevant compared to energy costs, then they too can become variable loads. H2 electrolysis and desalination and battery charging are all highly automated processes that benefit from those conditions today.

          The forever advantage of green H2 production is that it is containerizable. Can be transported seasonally to where renewable surpluses will occur. I guess self mobile robots could do the same, though.

      • Wanderer@lemm.ee
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        2 days ago

        Yes it can, I didn’t say otherwise. I’m not sure what your point is.

        The electricity grid is about matching supply and demand. Hydro is not going to stop massively amount of wind and solar being wasted in a 100% is it?

        Also most grids don’t have enough hydro storage or inertia to solve to problem by itself.