I don't know what you mean by "peak load", but it is 10% more electricity consumed. Electric cars rather help than load the grid, as their charging can be easily controlled to help balance the grid.

And yes, a small part of the battery capacity won't be "donated" but rather rented to the grid in exchange for much lower prices. VW is about to roll out a corresponding project, owners can expect much cheaper charging up to even free charging.

And no it isn't the Greens who are feeding the fossil fuel industry but those who hold back renewables and the electrification of transportation.