Science Technology This Clock Keeps Perfect Time, and Runs for Six Months Powered by Plain Tap Water By Derek Markham Writer Derek Markham is a green living expert who started writing for Treehugger in 2012. our editorial process Twitter Twitter Derek Markham Updated October 11, 2018 ©. Bedol Share Twitter Pinterest Email Science Space Natural Science Technology Agriculture Energy Most of us rely on a clock of some sort, in order to get where we're going at the time we need to be there, or to stay on track with our daily routine, and while many people depend on their watch (or more likely, their phone) for a personal timekeeper, homes and businesses may still need a wall clock that displays the time for everyone to see. One of the drawbacks to a wall clock is the need for power for it, which requires either a cord or batteries, both of which have their weaknesses. Being tethered to a plug means that the clock has to be mounted near an open outlet (which also means that the cord will be visible, which can detract from the design of the room). A wall clock powered by batteries needs... wait for it... batteries, which have to be purchased and/or charged. But there are other options, such as these water-powered wall clocks from Bedol. Water-powered, you say? How is that possible? You may remember from science class that a battery can be fashioned from a lemon or a potato, simply by placing a zinc electrode and a copper electrode into the fruit and taking advantage of the redox (reduction-oxidation) reaction that takes place. The clocks from Bedol, however, don't require a piece of fruit or a special electrolyte to generate enough electricity to run the timepiece, but instead use plain tap water. "This unique clock saves money and reduces the user’s carbon footprint by using a renewable resource that makes the need for normal lithium-ion batteries a thing of the past. Powered by ions found in regular tap water, The Bedol Wall Water Clock easily keeps time thanks to two proprietary metal plates specifically designed for Bedol clocks. Once the plates encounter water, naturally occurring positive (+) and negative (–) ions generate enough electricity to keep the clock ticking. It’s that simple. It’s that clean." - Bedol The Bedol wall clock can keep perfect time for six months (or more, up to a year) on a single filling of tap water, at which point all that is required is to pour out the water and refill it again. Considering that the price of tap water is negligible, especially when compared to the price of a battery, and powering a clock with it doesn't require any of our other precious resources, a water clock such as this one could be a great addition to an offgrid house or as another way to reduce our eco-footprint. The wall clocks from Bedol, which are themselves shaped like a drop of water, come in four colors, and are available from the company's website or at select stores. And if a wall clock isn't your thing, but you'd like a desk clock instead, Bedol has you covered there as well.