In theory, a world powered entirely by renewables is possible. But given the natural fluctuations of the wind, waves and sun, how can we ensure that the green energy market of the future is safe, fair and truly sustainable? An open source project Power TAC is using machine learning simulations to help us find out.

A emissions-tracking tool, developed in Britain, is using machine learning to work out if the next 96 hours of electricity has been sustainably produced - offering a big boost to both energy-consumer transparency and the transition to renewables.

Can energy be produced from the rustling of leaves and branches? Yes, say researchers from Ohio, who have already generated piezoelectric energy.