Well, the wind blowing on some hill somewhere in europe isn't of much help, it needs to be diverse enough that some countries can make up for the entire lack of production of other countries.

I am not convinced there is much diversification. I just did some back of the enveloppe analysis to convince myself. I am using hourly wind electricity production data from this source [1] which is referenced on the europa website [2] (first source I found, I don't necessarily vouch for it). I only looked at 2014-2015 (the last two years of this time series), took the daily production at 2pm (seems to be peak production and peak demand), and then calculated a weekly average of the 2pm production by country for every day. I took the low points for the UK (arbitrarily, that's where I am now), and looked at the percentile of each country for those UK low points.

So the way you read this is for the week ending 28 June 2014, when the UK was at its 1% worst wind production across 2014-2015, at that time Norway was at its 15%th worst production, Sweden 9%th worst, etc. "15%th worst" means that the norwegian production for that week was below that level only 15% of the weeks in 2014-2015.

                     2014-06-28    2014-09-09    2014-09-16
  United Kingdom             1%            1%            2%
  Norway                    15%           21%           20%
  Sweden                     9%            0%           11%
  Netherlands                1%           19%           18%
  France                     2%            9%           15%
  Germany                   23%            1%           41%
  Italy                     63%            9%           18%
  Portugal                  32%            5%           60%
  Greece                    55%            5%            8%

so you do get some outliers (Italy and Greece in the first column, Portugal in the last), but overall, all the major countries are down at the same time, so it's not Portgual that will produce the wind energy for all the other countries.

[1] https://zenodo.org/record/4803353 [2] https://data.jrc.ec.europa.eu/dataset/jrc-emhires-wind-gener...

I've looked at studies from researchers running simulations on weather data sets, and yes, you need some dispatchable sources in Europe. The question is how much you need.

Generally, the biggest issue seems to be heating in the winter. Heat is actually much cheaper to store than electricity. If you have a district heating system, you can even store it seasonally (storing solar heat in the summer) and be competitive with gas, even before the recent price increases.

I think the main reason we don't see a lot of cheapish long term electricity storage yet is that it's not needed. Once we start producing it, economies of scale will kick in. That's at least how it worked for PV, wind turbines, li-ion batteries.

Europe is windier in the winter, so if you choose a week in the summer, they're all going to be low. This is not unknown or unexpected. It's also neatly complemented by solar which has the opposite yearly cycle:

https://mobile.twitter.com/ntsafos/status/148056006004465254...

I have done all this research in like 2017 and I am so tired of all the idiots slowing down humanity's progress.

Which is great when everyone likes each other. Which traditionally is a dubious bet to place in Europe when losing it results in serious things like ‘will all the old people freeze to death tomorrow because we don’t have enough electrical capacity’.