Alternative fuels

Wired: Power your car with pee

A scientist at Ohio University has developed a catalyst capable of extracting hydrogen from urine. That’s right. Urine. Now you can fill one tank while draining another.

Gerardine Botte claims the device uses significantly less energy than is needed to extract hydrogen from water and says it could power hydrogen fuel cell vehicles in the near future. Her electrolyzer uses a nickel-based electrode to extract hydrogen from urea (NH2)2CO, the main component in urine. Hydrogen is less tightly bound to the nitrogen in urea than to the oxygen in water, so the electrolyzer needs just 0.37 volts across the cell to oxidize the urea, according to Botte. That’s less than half the amount of energy in an AA battery and considerably less than the 1.23 volts needed to split water.

In all the hoopla about hydrogen-powered fuel cells, it’s rare to find an article that includes the energy cost of generating the hydrogen. Hydrogen requires electricity, and if your zero-emissions car is ultimately powered by an emissions-spewing coal-fired power station, there’s no net reduction in carbon emissions. The article mentions hooking up the electrolyzer to a rooftop solar panel for better renewable energy usage.

I’d love to drive a vehicle that reduced dependence on imported oil, but emissions calculations that ignore the fuel cost are just pushing the pollution off on something else that may be a worse polluter than the humble petrol engine. Botte’s electrolyzer is the first decent hydrogen solution I’ve seen. This was mentioned in the Columbus Dispatch over a year ago, Wired is a little late to the party.


Wired is somewhat muddled on their units, 0.37v is less than 1.23v but that’s not an energy measurement because it’s missing the current part. Volts x amps = watts, which IS an energy measurement. Assuming they used the same current, then yes, that’s a drop in overall energy required to create hydrogen.)