The reality is that renewable energy is unpredictable and best suited to flexible generation. Please do not misunderstand me, I fully support the development of all renewable technologies. However, when we wean ourselves of fossil fuels, we will need new baseload power plants. Nuclear is currently the best option to provide stable baseload generation.
Do you have a source for this?
Because grids already deal with changing demand and if the generation is geographically distributed this issue could probably be solved with less storage than electrc cars are using. See this paper