This eco-toilet pays for human waste in digital currency

The BeeVi eco-toilet turns human waste into energy – and pays for the privilege.

Technology has created all kinds of new ways for people to make money. Now, thanks to Cho Jae-weon, an urban and environmental engineering professor at Ulsan National Institute of Science and Technology (UNIST), people are getting paid for their most earthly of deposits.

How it works: Located on the UNIST campus, these “BeeVi” toilets (a combination of the words “bee” and “vision”) are connected to a laboratory that converts excrement to methane, a biogas often used for heating.

  • A vacuum pump sends the human waste into an underground tank, reducing water use, where microorganisms break it down to methane. This methane is then used to power a gas stove, hot-water boiler, and fuel cell in the same building.
  • As remuneration for their efforts, anyone who makes such a deposit to the energy system receives 10 Ggool, a digital currency that Cho created.
  • Ggool, which means “honey” in Korean, can be used to buy a variety of items on campus at the Ggool market, including coffee, noodles, fruit, and even books. Students simply pick up the item they want and scan a QR code to pay with the digital currency.

“I had only ever thought that feces are dirty, but now it is a treasure of great value to me,” said UNIST postgraduate student Heo Hui-jin. “I even talk about faeces during mealtimes to think about buying any book I want.”

The math: It may make for a great headline, but does this poop-to-payment cycle actually work?

According to Cho, the average person defecates approximately 500 grams per day. This can be converted to 50 liters of methane, which can generate 0.5 kWh of electricity — or the equivalent of 0.75 mi for an electric car.

The digital currency may be experimental, but it has already proven a strong enough incentive for many students to participate in a recycling process that could have major applications if deployed on a larger scale.

“If we think out of the box, feces has precious value to make energy and manure,” Cho told Reuters. “I have put this value into ecological circulation.

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