In the future, we’ll all sit down by babbling brooks and simply dip a gizmo into the water to charge up our phones.
That’s what some optimistic hippies believe, anyway.
You’ll need to be fairly patient: the Blue Freedom takes an hour to charge up after you dunk it in moving water, using a micro turbine to generate electricity.
Its makers – who are currently seeking funding via KickStarter – describe it as the ‘world’s smallest hydroelectric plant’.
It works on a similar principle to the larger plants using hydroelectric dams – but is aimed at remote communities and developing economies.