It so happens that Exxon Mobil has been funding research into this problem at Stanford University for almost a decade now without a major breakthrough.

FORBES: Natural Gas Equals Energy Independence And Economic Rejuvenation

But as evidence of a problem has become clearer, ministers had decided to put a "significant extra boost" into research.

BBC: Dying bees 'were not a priority'

Although research into solar power has come a long way, sunset still poses a problem.

ECONOMIST: Looking to leaves for a way to store solar power after sunset