You don't need batteries with longer capacity in terms of power:energy ratio, you simply need more batteries.
Getting to France's level of nuclear decarbonization with batteries is cheap and easy with current prices. Using existing thermal plants for a few weeks a year and renewables for the rest is quite similar overall to France's mix.
What's challenging is the final 10%, 5%, and 1%. But it will take 15-20 years of deployment of our current cheap renewables+storage technology before we need to solve those final percents. In that time, technology will have advanced tremendously and we don't know what the cheapest solution will be, just that it will be cheaper than current tech. Plus it would take much longer than 15 years to even build nuclear in any significant quantity! France said a few years ago that they would be building handful of new reactors but I still have not seen progress!
Getting to France's level of nuclear decarbonization with batteries is cheap and easy with current prices. Using existing thermal plants for a few weeks a year and renewables for the rest is quite similar overall to France's mix.
What's challenging is the final 10%, 5%, and 1%. But it will take 15-20 years of deployment of our current cheap renewables+storage technology before we need to solve those final percents. In that time, technology will have advanced tremendously and we don't know what the cheapest solution will be, just that it will be cheaper than current tech. Plus it would take much longer than 15 years to even build nuclear in any significant quantity! France said a few years ago that they would be building handful of new reactors but I still have not seen progress!