Urban and environmental engineering professor Cho Jae-weon of Ulsan National Institute of Science and Technology (UNIST) in South Korea has created an eco-friendly toilet that converts human excrement into energy.The toilet, named BeeVi (for "bee" and "vision") used a vacuum pump to send excrement into an underground tank where microorganisms break down the waste and produce methane, a biogas that is used by the school to create energy.An average person produces enough excrement daily to create 50 liters of methane gas, which in turn can produce 0.5 kilowatt-hour of electricity.To "reward" students for their, ahem, deposits, Cho created a virtual currency called Ggool (or 'honey' in Korean). Each person that use the toilet earns virtual currency that can be used to buy goods on campus - from coffee to instant cup noodles, snacks, and even books.Via <a href="https://interestingengineering.com/south-korean-toilet-allows-students-to-pay-with-their-poop" class="on">Interesting Engineering</a>​Image: Ulsan National Institute of Science and Technology#methane #biogas #toilet #energy #virtualcurrency #poop