Love these DIY batteries made from coffee grounds, aluminum, copper and salt water by mischer’traxler. The design was one of three winning entries in a competition entitled SUSTAIN.ABILITY.DESIGN, sponsored by Vienna Design Week organizers Neigungsgruppe Design and Nespresso Austria.
The energy for the movement of the sweep hands is powered by 17 simple, self made batteries. Each battery-block consists of used old aluminium capsules, coffee grounds, strips of copper and salt water. In this mixture between a soil battery and a salt water battery the aluminium functions as the anode, the copper as cathode and the salt water as electrolyte. Due to a chemical reactions a small, but usable, amount of energy is created. Each battery produces about 1,5 – 1,7 Volts of potential and enough power to run a electro–mechanical Quartz clockwork.
Some quick back-of-the-envelope calculations based on my personal coffee consumption over the past decade suggests I could have built a battery large enough to reduce foreign oil dependency in the U.S. by about 15%. (via dezeen)