The Power of Pee: Researchers Develop Urine-Powered Fuel Cells

Urine powerPhoto: fudj

Human waste will never be looked at the same way again. Researchers from the Bristol Robotics Laboratory at the University of Bristol, England, recently reported in The Journal of Physical Chemistry that they’ve developed a fuel cell that uses urine to generate electricity.

The urine-tricity project consists of microbial fuel cells (MFC) that use bacteria to make urea, a chemical in urine, generate electricity. Wastewater treatment plants regularly use bacteria to break down waste, but the difference is that those processes are energy intensive, whereas Bristol’s approach actually generates energy, explains Dr. Ioannis Ieropoulos, a lead researcher at Bristol.

The amount of energy produced is minimal. One cell produces a current of 0.25mA, about enough to power a hearing aid. Though one cell’s output is miniscule, the team is working on making them smaller and stacking many of them together. At that point, power generation becomes a real possibility.

Since urine is produced everywhere, and a lot of it too — humans alone are estimated to produce 6.4 trillion liters a year — this idea has a strong local flavor. The ability to produce energy locally could give this technology an edge against other renewable energies such as solar and wind that are only cost-effective in certain areas.

The team is initially targeting micro-generation for the home. That poses the big question of whether people are willing to separate their urine from their fecal matter. Toilets exist that can do the trick, it’s just a matter of getting people to convert. Another possibility is keeping the regular toilet and installing a urinal. A welcome addition to any bathroom for guys, but who knows, ladies may learn to go a different way too.

Urine contains organic compounds such as nitrogen and phosphorus that when released into the environment in large amounts can pollute rivers in much the same way fertilizer does. Wastewater treatment plants put much effort into filtering these compounds. MFCs can capture those nutrients to reuse as fertilizer, yet another benefit of this emerging technology.

It’s urine-tricity’s many benefits that excited the Bill and Melinda Gates Foundation to fund this project through their Grand Challenges Explorations program, an initiative aimed at facilitating unorthodox ideas capable of solving persistent health and development challenges. As a local source of power, urine-tricity can have a substantial impact on the developing world.

This project is not without its challenges. Aside from the societal shift in bathroom habits, there’s always the all-important challenge of being economical. It doesn’t matter how efficiently the technology works, if it isn’t cost-effective, it isn’t going to make it.

This technology is nothing new. Dr. Ieropoulos has been working with MFC technology for a decade now to power energetically autonomous robots called EcoBots. Older versions of the EcoBot have been powered by sugar, dead insects and food waste. These years of experience will no doubt lend legitimacy to a project that’s one among many in the competitive renewable energy field.

In the ’70s, John Lennon sang “Power to the People.” Michael Franti updated it in the ’90s to “Power to the Peaceful.” As fossil fuels become totally uncool in the ’10s, maybe we’ll now be singing a different tune altogether: “Power to the Pee-ple.”

Sources: 1, 2, 3