Ulsan National Institute of Science and Technology (UNIST) has shown that a person's poop can generate income that can buy books, fruits or coffee.
Cho Jae-weon, an urban and environmental engineering professor at UNIST has devised a virtual currency called Ggool, which means honey in Korean. Each person using the eco-friendly toilet earns 10 Ggool a day, according to Reuters.
Cho designed an eco-friendly toilet connected to a laboratory that uses excrement to produce biogas and manure.
The BeeVi toilet—a portmanteau of the words bee and vision—uses a vacuum pump to send feces into an underground tank, reducing water use. There, microorganisms break down the waste to methane, which becomes a source of energy for the building, powering a gas stove, hot-water boiler and solid oxide fuel cell.
“If we think out of the box, feces has precious value to make energy and manure. I have put this value into ecological circulation,” Cho told Reuters.
An average person defecates about 500g a day, which can be converted to 50 liters of methane gas, the environmental engineer said. This gas can generate 0.5kWh of electricity or be used to drive a car for about 1.2km (0.75 miles). Thus when you use the toilet, the human waste is being used to help power a building and you earn the money. The students can pick up the products they want at a shop and scan a QR code to pay with Ggool.
“I had only ever thought that feces are dirty, but now it is a treasure of great value to me,” postgraduate student Heo Hui-jin said at the Ggool market. “I even talk about feces during mealtimes to think about buying any book I want"