Though typically uttered with more vulgar language, the off-color remark of “defecating a brick” usually signifies a person’s shock. Once you see this solar-powered toilet, you may be inspired to do the same, quite literally.
Led by Karl Linden, a environmental engineering professor at the University of Colorado, a team of engineers built the Sol-Char, a toilet that scorches waste via fiber-optic cables, heated by solar concentrators on the roof. The system produces a useful byproduct called biochar, a sanitary charcoal briquette-like material that can be used for agricultural fertilizer and soil amendment.
“A solar concentrator has all this light focused in on one centimeter. It’d be fine if we could bring everyone’s fecal waste up to that one point, like burning it with a magnifying glass,” Linden told Motherboard. “But that’s not practical, so we were thinking of other ways to concentrate that light.”
Eight parabolic mirrors aim the sun’s rays onto a postage stamp-sized collector, which is then beamed into the cables. When heat combines with photons in the “reaction chamber,” 700 watts incinerate the waste at up to 600 degrees Fahrenheit.
Though tweaking the toilet is an ongoing effort, Sol-Char’s current design remains a high-powered, poo-torching outhouse. “The transmission efficiency is really high; it’s like 90 percent as you don’t have many losses,” Linden said.
Researchers built the Sol-Char as part of Bill and Melinda Gates Foundation’s Reinvent the Toilet challenge, which seeks to bring radical, sustainable change to sanitary facilities in developing nations. By sanitizing waste without the need for large treatment facilities or massive infrastructure, Sol-Char remains “off the grid,” one of the challenge’s goals. The project received $777,000 initial funding from the Gates Foundation and an additional $1 million in a second round.
The team is currently in New Delhi for the second-annual Reinvent the Toilet Fair, where Linden and company will present their working prototype.
”Our system right now is not field ready. It can operate, and all our technology can work in an integrated fashion, but we have to be there,” Linden said. “The next phase of the research is to take what we’re doing now and make it ready for the field.”
Credit: University of Colorado