You don't need that. A grid at the country scale is enough. Power is less consumed during the night, so using only wind by night is alright. Plus we already ha

You don't need that. A grid at the country scale is enough. Power is less consumed during the night, so using only wind by night is alright. Plus we already have "grid-contract" with neighbors in France to load balance. And even the biggest defenders of solar and wind don't advocate for going 100% at first. Mixing sources and increasing solar / wind gradually years and years is already nice.