Bazz,
Don't know how you could've reached that conclusion. It didn't look to me like this article had even woken the cat up, let alone move it anywhere.
All this article shows is that it's a big task... well duh!
But big doesn't mean impossible. Big things are accomplished all the time.
And the article says almost nothing about the affordability. Worse still, what it does say is based on historical costs (without factoring in the effects of improving technology) and fails to recognise that a large overbuild would decrease the firming costs.

And of course at a global level, sticking with fossil fuels is the most expensive option of all.