We should rather create thousands of small underground structures in small valleys and dales, close to homes. That is to say, two underground basins - one at the top of the hill and the other at the bottom - connected by two underground pipes - one allowing water to flow (under pressure) to generate electricity via a turbine in the lower basin and the other pumping water from the bottom to the top via photovoltaic solar panels installed on nearby buildings! A dead simple way to store electrical energy, available at any time and which would have only a very limited visual impact! We could even imagine, through new construction legislation, using solar panels to store electrical energy via counterweights on the north façades of buildings or in underground tanks via compressed air! SMALL IS BEAUTIFUL! But that won't please the powerful electricity lobby lol!

Yes, that would be good. As for where we could build a new dam, I don't know.

However, we can raise the height of a number of existing dams and why not dig the bottom of these same lakes a bit deeper.
The potential for purchasing wind and photovoltaic electricity at 1 ct/kWh for pumped storage would increase.

On the European market daily and even more so at weekends, renewable electricity is sold at rock-bottom prices - finding ways to use it is part of the solution.

Stopping the increase in consumption, for example with electric cars, data centres and other streaming, gaming and bitcoins, would be the most effective lever.
Restricting your child's online gaming hours is a daily challenge.