Fart in a jar: scatological solutions to energy needs

Cars first began to sport bumper stickers that read “Save Gas, Fart in a Jar” during the oil shocks of the 1970’s. Now as gasoline prices again spike, this tongue-in-cheek advice may actually be on to something. Rather than relying on biofuels that are derived from food crops, renewable energy developed from food that the body already processed and eliminated might be a solution to our energy needs. Two technologies purport to do just that: to turn urine and excrement into energy.

At Ohio University, Gerardine Botte developed technology to generate hydrogen from urine. Like hydrolysis – which splits hydrogen from water – Botte uses electrical current to extract hydrogen from the urea and ammonia that comprises pee. But since hydrogen is not bonded as tightly in either urea or ammonia, the process needs much less energy. Botte figures that the urine from an office of 200-300 people could generate 2 kilowatts of power. Perhaps not a lot, “but every drop in the bucket helps.” The technology could also be applied to animal feedlots. The urine from 1,000 cows would make 40 to 50 kilowatts of power. As an added bonus, the process would also eliminate ammonia, and reduce wastewater treatment costs.

Folks in China are taking the scatological solution another step further. Instead of septic tanks, they are using anaerobic digesters to treat animal or human waste. Microbes in these airtight tanks break down the waste and produce methane, which is then used for heating and cooking. Not only does the process produce free energy, it also decreases global warming by up to 54% compared to heating with coal or wood, as well as reduces indoor air pollution. Presumably, the biogas does not smell either.

These solutions mimic what nature already knows: you let nothing go to waste. Biological systems have been converting sunlight and food and water into energy for eons. It’s time for us to learn from nature and harvest the energy we produce instead of merely being energy consumers.