Due to technological trajectories set in motion by past policy, a global irreversible solar tipping point may have passed where solar energy gradually comes to dominate global electricity markets, without any further climate policies

  • Eheran@lemmy.world
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    1 year ago
    1. You still need the massive excess capacity then. Costs x2 or x3 are a big change. Without seasonal storage you need a global grid as well as that massive excess capacity. That not only costs extremely much (this was the argument against nuclear) but would also be impossible given the unstable relations around the world, let alone terrorists who only need to cut “one line” to remove power from all of Europe. Not going to happen.

    Hydrostorage is absolutely nothing and can not be significantly increased, just like hydro power. Take a calculator and see how long it lasts. World wide it’s 180 GW of power and 1.6 TWh energy, as per wiki. The USA need over 4000 TWh yearly, they empty the whole world capacity of hydro storage from 100 to 0% in 3 hours. Just the USA alone.

    • MrMakabar@slrpnk.net
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      1 year ago

      That was exactly my point, you do not need a global grid for this to work a continent sized one already does a great job. That was why I used the EU as an example. As for seasonal storage the worst month last year had 42.8% renewables, which was March, the best was February so a month earlier with 60.0%. The average was 49.7%. So we are talking 20% up or down. That is also true when you just look at wind and solar. Average was 47.15GWh and the worst month was 40.97GWh and the best 59.00GWh. So again fairly even distribution over the entire year. So no need for seasonal storage, unless you have something super cheap.

      That is real world data and not some crazy stuff. You basicly just have to overbuilt by 50% and add a days worth of storage to the EU grid to work and the ability to move around electricity.

      Also I am talking about hydro power, which per wiki only makes up 16% of global generation. That has storage capabilities built in current reservoir power plants. https://en.wikipedia.org/wiki/Hydroelectricity#Properties

        • MrMakabar@slrpnk.net
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          1 year ago

          Right now Sweden and Norway have 118GWh of hydro storage and there is more in other EU countries. That alone is enough to power the EU for two weeks or so. But even that is not entirly needed as Europe is large and diverse enough geographically to have different weather in different countries. So power can still be moved. Even on the worst day of last year wind and solar were still able to produce 8.5% of the EUs electricity production so 37% of average levels.

              • Eheran@lemmy.world
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                1 year ago

                Thank you. However, that is the yearly amount of energy. Not the maximum storage capacity at one point. Like (dis)charging a battery once <-> discharging it many times over the year. So over the whole year this massive storage was able to produce the energy needed in 2 weeks.

                • MrMakabar@slrpnk.net
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                  1 year ago

                  It is absolutly the storage capacity at one point. . As in the first link:

                  Norway has more than 1000 hydropower storage reservoirs with a total capacity of more than 87 TWh. The 30 largest reservoirs provide about half the storage capacity. Total reservoir capacity corresponds to 70 % of annual Norwegian electricity consumption.

                  That is not that crazy. It just means that less then 10% of global hydro reservoir storage is in two European countries, with a lot of water and mountains. Hydro is by far the biggest storage capacity we have. To put it in the words of the iea and globally speaking:

                  The reservoirs of all existing conventional hydropower plants combined can store a total of 1 500 terawatt-hours (TWh) of electrical energy in one full cycle – the equivalent of almost half of the European Union’s current annual electricity demand. This is about 170 times more energy than the global fleet of pumped storage hydropower plants can hold today – and almost 2 200 times more than all battery capacity, including electric vehicles.

                  Source: https://www.iea.org/reports/hydropower-special-market-report/executive-summary

                  • Eheran@lemmy.world
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                    1 year ago

                    So that are the numbers for dams (since pumped storage is extra and much smaller). That is not (electrically) rechargable storage. It is storage, but bound to the influx of water and with many constraints about how much water can be released at what point, how much it has to have at least or at most at which point in year to prevent floods or droughts etc. That is not the kind of storage we need for solar and wind. And while the storage capacity is high, the available power output is not. Since they maximum anyone would install is going to be correlated to the influx of water, not to the fastest possible draining of the reservoir - which nobody would ever want to do.

                    Also, thank you for the interesting discussion.