A bleak autumn day at Methil on the south Fife coast. In front of us, the once-thriving yard where some of the North Sea’s biggest oil and gas platforms were built is almost empty. There’s just mud, puddles and piles of rusting steel. If Scotland had tumbleweed, it would be tumbling. ‘This was supposed to be the seething epicentre of the green industrial revolution, the Saudi Arabia of windpower,’ retired GMB union convenor Mike Sullivan, 70, tells me. We’re standing on a low hill overlooking the yard, facing the sea. He shrugs and gestures to the scene in front of…