Problem: the capital & maintenance costs of the grid vary very little with its utilization %. So if you build loads of wind & solar & battery all over - eithe

Problem: the capital & maintenance costs of the grid vary very little with its utilization %. So if you build loads of wind & solar & battery all over - either (1) you've got to build so much battery capacity, all over, that you'll never need the grid, or (2) you've still got to build the grid to get you through occasional "calm & dark" periods. Either way, you're looking at vastly higher capital expenses.