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

    • 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.

                • MrMakabar@slrpnk.net
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                  1 year ago

                  Most of that is fine during a dunkelflaute. The only really big issue is not having enough generating capacity, but even that likely works out. The most fuel generation during a single week last year was 24,302GWh so 144GW running throu. Sweden and Norway can generate 49GW in hydro at full power. Even the best weeks still have over 12TWh of fossil fuele generation in the EU, so that certainly goes a long way to solving the problem of dunkelflaute.

                  But you are right, most of the year smaller storages to cover a night or so, is all you need. So you still want some TWh of battery and pumped hydro storage. That preserves hydro storage and is needed to balance the grid. Biomass is also worth a look for long term storage.