BEIJING -- An American professor and designer is trying to change the world by reinventing the toilet by turning waste into fuel.

"Poop-power is taking human waste by-products and extracting the energy from the waste, and using the energy for useful things," Michael R. Hoffmann, a professor at California Institute of Technology (Caltech), told Xinhua in Beijing.

He was attending a next-generation toilet campaign that was launched in the city last week, as well as promoting his own design.

His dream is that one day all feces can be disinfected and processed into hydrogen for electric power generation. His whole toilet unit includes processing machinery and a storage tank for the hydrogen. It is designed for 40 uses per day.

The 70-year-old's vision is that one family will be able to sustain their daily electrical needs using their own excrement and reuse the water they urinate after processing it in their own bathroom.

More importantly, in this "brave new world," each family will only need one next-generation toilet, according to Hoffmann, winner of the "toilet revolution" campaign held by the Bill & Melinda Gates Foundation last year.

"The whole unit will cost the same price as an iPhone and you can charge your iPhone with your own poop-power," said the professor, who is also academician of the National Academy of Engineering.

The toilet had never been fundamentally changed in the last 200 years after it was invented 1775, until the likes of Hoffmann tried to create "toilet 2.0."

He came up with the new idea in 2011 when he was first attracted by a US military toilet project. The military was interested in independently operated toilet systems to be used by troops around the world, including Afghanistan and Iraq. "They didn't want to have to use fuel power generators. They wanted something that would be self-contained," Hoffmann said. However, the military decided against taking his toilet idea forward.

The Gates foundation then came forward with a similar idea.

The foundation defined the "next-generation toilet" as waterless, hygienic, not requiring a sewer connection or electricity and costing less than five US cents per user, per day.

"Although we can fly people to the moon, 40 percent of the world's population - 2.5 billion people - practice open defecation or lack adequate sanitation facilities," said Dr. Doulaye Kone, senior officer of water, sanitation and hygiene of the Gates foundation.

Even in urban areas, where household and communal toilets are more prevalent, 2.1 billion people use toilets connected to septic tanks that are not safely emptied or use other systems that discharge raw sewage into open drains or surface waters.

Thus, the foundation extended its global "toilet revolution" campaign to China, kicking off a competition with grants of $5 million to encourage Chinese talent to reinvent the toilet.

"Imagine each person discharges 1.5L urine and 300g of feces per day, and if you multiply the number of people of Beijing, how much stuff has to be processed on a daily basis," Hoffmann said.

The processing is a huge project and demands large scale applications, instead, small facilities like his invention could do the job in each home, he said.