The tiny fraction of output on overcast days is negligible.

Well, on overcast days most solar panels these days still produce up to 25% of their normal output. Nothing to sniff at I’d think. Perhaps not enough, but certainly not nothing.

I doubt that we can bridge it with power from intercontinental transmission lines, given how the politics look like today and how much they need to change first + then actually starting to plan and build it… In 50 year perhaps.

I think you may be a tad pessimistic here. Consider Europe, even during a Dunkelflaute not the entire continent is without renewables, only a region of it. If northern Europe has one, southern Europe is very, very unlikely to have one as well for example. And inter-continental power lines aren’t as rare as you might think! I believe the UK is currently building one to Morocco, and there’s plans to build one via Greece and Cyprus to the Middle-East.

Batteries are not relevant now and won’t be in the foreseeable future due to monetary, resource and manufacturing bottlenecks. Storage of electricity to later use it as electricity is simply not feasible right now, apart from the minutes you get from existing hydro storage.

I don’t fully agree here. Certainly on a more household level battery storage is already perfectly feasible and being installed a lot these days. The growth of this sector is also staggeringly high. Year-on-year the sector nearly doubles, as costs are coming down quite quickly and the economic picture starts to maie more and more sense. We don’t produce enough now, but in 10 years that picture might be radically different.

Right “now”, so in the next decade, if we push modern nuclear instead of fossiles (which we need to keep building due to said fluctuations) we will get far less CO2 quickly.

Experience learns that new nuclear reactors take 15 to 20 years to build, from planning to end of construction. If the focus is on nuclear, any CO2 savings will likely come too late. And then there’s still the economic problem of nuclear being far too expensive compared to solar/wind. Barely any investor is willing to touch it unless the government super-heavily subsidises it, resulting in expensive power and higher taxes (e.g. what happened in France). And then there’s the issue that we don’t have enough expertise and rare materials to build enough reactors to cover enough of the world’s production. We have a hard enough time building just a couple reactors, let alone thousands. And having poorer 3rd world countries finance their own reactors also seems unlikely.

I believe I saw research that suggested the fastest route to net zero, whilst still being affordable and feasible without emitting too much CO2 in the meantime was a very heavy push for renewables, investments into energy infrastructure (which are mostly required regardless of the route taken) and research into battery tech so that in 25-30 years we may have enough storage to ditch the last fossil fuel plants. In the meantime keeping gas power plants open seemed the least polluting backup method in case of power generation dips, plus potentially shutting off heavy industry during those periods to save power (fairly cheap, requires little investment to do). Nuclear doesn’t have to disappear, but the cost-benefit analysis just didn’t tilt in its favour. But it might make sense on a more local level perhaps, that’s always an issue with those super macro-economic studies.

I was hoping to find it but I’m having a hard time doing so. If I find it I’ll link it to you, it was an interesting read.