Dude, just stop talking about the European grid, you just do not get it nor the political climate.
As for BEVs..market penetration will depend on a number of factors (taxes, incentives, charging stations, cost of petrol etc), but IMO the most important factors are price parity/range of models/ and importantly, critical mass. But, since it's been a rainy day, I've done some simple predictions for you (Note: BEV only).
My numbers - and I've done several iterations/countries, all giving similar adoption rates - indicate that in 2025 UK will have ~20% BEV market share (image). Numbers for Europe as a whole looks very similar (~21%; inset).
Will be prediction be on the optimistic side? Maybe. Will it be on the low side? Possibly. There is a big push to stop all new ICE car sales in Europe by 2030 - if this is ratified next year, then my prediction is likely to be on the low side. FYI, it took Norway 5 years to get from 2.8% BEV (2012) to 22% (2017) - yes, strong incentives, but hardly any models to choose from.
How will they charge? Home charging, home solar, and when not at home then just this year (Jan-Sept) charging stations have gone from 18,500 to 26,600 in UK.
Where do they get power from? Wind power is just an example - here in the UK, wind power capacity is 22GW, 2025 it's projected (planned) to have 35GW capacity (low projection; more the better for LYC, HUGE permanent magnets, specially offshore).
Cleaner grid, better batteries, more models.
Time will tell. Save this post and call me up on it, yearly if you so wish.
PS before some people get their knickers in knots, this is for the European market - I have not done any analysis of Asia/USA as I'm not clear on the political climate in these regions (bit up in the air, although waiting for China to decide on the 60% ev adoption by 2035).
(20min delay)