Lots of options, but here's one: $20B buys massive amounts of HVDC to interconnect and trade with distant parts of the continent and enable trade in both directions for intermittent renewables. HVDC has shorter lead times and lower cost overruns too. Multiple lines are important too, because those massive inverters don't work 100% of the time.
Fortunately we've already got ~5GW+; but cold still winter days are tending to affect large areas at the same time for extended periods of time; those are the days when everyone is at peak usage and has ~no solar. The last time the UK power grid had to raise a warning (a few years back) was a cold still February when the whole continent was low on wind generation, and you could see that a couple of weeks back where we were running coal generation and exporting to France (well the EU grid) at the same time.
We have a significant amount of HVDC already. Not sure how that helps as there is still many many days when there is 0 wind across the whole of the EU.
Not to mention as the article states the closest big nation, France, is on the verge of an energy crisis itself....
