Re: One of the factors I'd be interested in
"Electric vehicles - when parked at home - can conversely help to smooth the demand upon the grid, by using their batteries as local storage."
You could charge the battery off-peak which eases Neil's worry about generating capacity although the overall amount of power generated still increases as he says.
But you seem to be implying that you could use the battery to store power for the home. You'd be a bit annoyed to get into your car and find it grind to a halt a few yards down the street because you'd just been using its battery to cook your breakfast.