I don't think there would be nearly enough money to cover evacuation and rebuilding. Solar is already on track to become cheaper and more reliable than fossil fuel power, so the funds brought in by a carbon tax will diminish rapidly when there's no economic reason to use polluting power sources at a large scale.
Solar right now is hundreds of billions away from being ready. For a medium sized country
Cant give a source, but the figure ive seen is 150 billion € in Germany, for nearst future.
You need to install overcapacity and service it.
You need to rebuild the grid from the ground up, overengineer it massively.
You need to add storage, at great expense and huge drain (batteries tend to become worn out in a few years)
