In 2004, Peter Brewin, an industrial-design student at the Royal College of Art in London, set about creating a more efficient shower that doesn't require lower pressure. It couldn't just capture and recirculate the water; most countries require shower water to meet potable-water standards. So instead he designed a miniature treatment plant that continuously captures, cleans, and recirculates 70 percent of the water used during a shower. Even with the energy the system consumes, it still uses 40 to 70 percent less power because the system doesn't have to heat as much water. Over the course of a year, a typical household would use 20,000 to 32,000 fewer gallons of water with Brewin's system. That, in turn, would save a local treatment plant upward of 200 kilowatt-hours of energy.