The hydrogen economy is still years away, if it exists at all, but that isn’t stopping researchers finding ways to make the gas on the cheap, and from any range of materials.

The most recent development is in the bacterial arena, with the latest microbial fuel cells able to convert everyday waste into electricity with unprecedented efficiency, according to a paper by Bruce Logan in this week’s Proceedings of the National Academies of America. The process has bacteria chewing up sugars, cellulose or some common acids. During this oxidative process, the electrons released scoot over to an anode, and the protons, that balance this particular equation, go into solution. Normally, oxygen would be added, and would react with the protons and electrons to make water. But leave out the oxygen, and add a bit of oomph in the guise of applied voltage, and hey presto – hydrogen is made.

Logan’s system is an updated version of his previous work, tweaked so that it can work from a range of biomass-derived stuff, even the contents of a salad bar according to the press release.

While most coverage played it straight, and trumpeted the 288% efficiency boasted by Logan, others took greater care in explaining how near, or far, the hydrogen economy is.

Logan’s achievement is certainly impressive. When the system was run with acetic acid, he managed to get 99% of the theoretical efficiency, in terms of hydrogen production. The challenge now, according to one commentator I asked, is to improve the rate of hydrogen production, which for now remains rather sluggish.

By Katharine Sanderson

Image: Microbial electrolysis cell with power supply used to boost the voltage produced by the bacteria / Photograph by Shaoan Cheng, Penn State University