What do you see as a small percentage? A country like The Netherlands is generating between 10% and 50% renewable energy without significant storage capacity (it's summer so a lot of that energy comes from solar, but in winter the yields from wind will be higher), and we are one of the worst countries in the EU when it comes to renewables. I thought the need for storage is mostly a problem if you want to reach a high percentage of generation using renewables. Anyway, energy storage also seems beneficial if you want to build a nuclear infrastructure, so it seems like a problem that has to be tackled regardless.
> They are cheapest because they are subsidised on one hand, and on the other hand, nuclear is penalized by lawsuits and regulartions and inspections
I don't think subsidies are really a problem. Weren't the nuclear power infrastructures of France and Ukraine mostly build using state subsidies? The amount of subsidies needed to build renewables is also decreasing. Some might argue subsidies aren't necessary anymore, but we still need massive infrastructure investments to create a smart grid, more interconnectors, etc. Also, nuclear energy might be regulated too much, but I'm not sure how much can be saved without hurting safety.