In what feels like the blink of an eye, cheap, bountiful natural gas has been controversially unlocked across swathes of the US by “fracking”

In the eyes of some, this shale gas represents an environmental catastrophe and an existential threat to renewables.

For others, it is a near-perfect complement to renewables, offering the prospect of a gentler, less economically disruptive transition to a coal-free future.

And