I still don't think National Grid's executives get it.
I'm from New England in the USA. I have earned the privllege of complaining about National Grid's managers because they sell me my electricity too, as they do for you lot in UK.
Here's what the Nat Grid people don't get: Electrical energy distribution is becoming a fine-grain information business. The grid that works in 2050 will be one that can rapidly control a large fraction of its load, as well as deliver the energy.
EVs already have user interfaces where the user can tell the car, "I need you at 0700 tomorrow" and the car can draw power "off peak". All that's left for the smart grid to do is run auctions in real time (the way web sites do when showing me banner ads). And we'll have a grid that can use much less peaking generation capacity than it does now.
Come up witth auction-capable controllers for hot water heaters and other domestic loads, and it gets even better. Those things, at volume, should cost no more than twenty euros / quid / bucks.
Yes, big-system transmission capacity will help. But a smart grid will help a lot more.
As of now, all National Grid can manage is a little pilot program in a small city called Worcester, Massachusetts (we pronounce it in the English way, "wooster") with two rates based on time of day. Unnecessary AND insufficient.
(Ultility economics in the US guarantee a return on capital, so Nat Grid has much more incentive to do big capital buildouts.)