Ulsan National Institute of Science and Technology's Cho Jae-weon is an urban and environmental engineering professor. He has cooked up an eco-friendly toilet. But not only that. Cho's loo is connected to a lab that uses poop to produce biogas and fertilizer.

South Korean professor Cho Jae-weon invented a toilet that turns poop into energy and pays people in digital currency.

A person defecates~ 500g/day converted into 50 liters of methane gas which generates 0.5 kWh.

Toilet users earn Ggool, a literal sh3t coin. pic.twitter.com/DCn3WteII5

� Brian Roemmele (@BrianRoemmele) August 17, 2022

The toilet uses a vacuum function to spirit away the poop into an underground tank, skipping the use of bucketloads of water. In said tank, specially inserted microorganisms break down the poop and turn it into methane. The methane is then used as energy for the building. So far it has been used to power a gas stove, heat water and it powers a solid oxide fuel cell. "If we think out of the box, faeces has precious value to make energy and manure. I have put this value into ecological circulation," Cho said.

While some commentators think it isn't worth it unless it works at scale, there's no reason why humans can't build this into a massive thing. If a person poops around 500 grams of the good stuff daily, then the result is 50 litres of methane gas, generating 0.5kWh of power. This will power a car for 1.2km, or 0.75 miles. Realising that means that the more people poop in your toilet, the more energy you will have, public spaces like gyms and restaurants will do well to convince humans to come and spend time in the smallest rooms in the building. Professor Cho has developed a cryptocurrency called Ggool (it translates as honey) to entice people to poop where it will be put to good use. Every person who donates a poop in the special throne earns 10 Ggool. Already, the Ggool can be used to buy stuff. Students at the university can buy things like coffee, noodles and books on campus.