Coffee makes the world go 'round for millions every day, but in Vienna over 700 dirty, used Nespresso capsules were combined with copper and salt water to make battery-powered clocks, that linked together to keep a radio playing away happily.

Supposedly the average coffee-drinker can get through 700 Nespresso capsules a year, which are discarded without thought. On display at Vienna Design Week, the installation highlighted recycling and sustainability, but also caught the eye of passers-by as the coffee grounds produced enough energy to keep the radio playing. Certainly something to think about as you brew the next pot of coffee. [Mischer'Traxler via Dezeen]