What's a beer battery?

Electricity from beer? It may sound like a farfetched idea cooked up after a few pints at the pub, but a partnership between Foster’s Brewery and scientists at the University of Queensland in Australia and the University of Ghent in Belgium has produced such a marvel. The "beer battery," as it’s being affectionately called, is actually a microbial fuel cell (MFC). The fuel celluses sugar-consuming bacteria to generate power from waste water produced in the brewing process. The bacteria consume the organic matter in the brewery’s waste water, breaking down alcohol, starch and sugar. The byproducts from the process are electricity, clean water and carbon dioxide, all very Earth-friendly.

Brewery waste water is particularly desirable for such an experiment because it’s biodegradable, says Professor Jürg Keller of the of the University of Queensland [ref].

The study was funded by a Queensland Government Sustainable Energy Innovation Fund Grant (about $115,000 U.S. dollars) and a grant from the Australian Research Council (for a little more than 1 million U.S. dollars).The university’s prototype MFC was 10 liters, or 2.6425 gallons, but the final cell, to be installed at Foster’s brewery, will hold 660 gallons. The MFC will likely produce 2 kilowatts of power, or enough to power an average home, and will be operating at the brewery by September.

"It’s not going to make an enormous amount of power -- it's primarily a waste water treatment that has the added benefit of creating electricity," Professor Keller told the Associated Press [ref]. For a country like Australia, which is experiencing its worst drought in 100 years, the ability to salvage and purify waste water could be especially valuable [ref].

Foster’s microbial fuel cell could spawn similar devices to be used across the food and beverage industry, which generates a lot of organic waste. Because microbial fuel cells are well suited to disposing of this waste, they have generated a lot of interest lately among researchers. Like Foster’s beer battery, MFCs convert chemical energy trapped in a "bio-convertible substrate" (meaning some sort of organic matter) to electricity [ref]. The bacteria act as a catalyst, facilitating the reaction.

Perhaps a sign of the excitement developing around MFCs, there is the first Web site "completely devoted to the beauty of microbial fuel cells" and several blogs covering MFCs and related topics. In September 2007, a four-day conference called "Anaerobic Digestion: Bio-energy for Our Future" is meeting in Brisbane, Australia, where particular attention will be paid to methods of gleaning energy from waste matter.

So will the beer battery start a green revolution? Probably not, but it’s certainly an intriguing method to clean up waste, harvest energy and produce clean water. It also speaks to a growing trend in which many companies are going green by investing in a wide range of projects, large and small, rather than seeking out one panacea. While ethanol- or hydrogen-powered cars and cheap, ubiquitous solar power may eventually revolutionize the automobile and power industries, instituting many small, eco-friendly projects can have an equal, if not, greater impact.

One brewery is actually a step ahead of Foster’s. In fact, when Foster’s installs its MFC this summer, it won’t be the first brewery using microbial-munching bacteria to clean waste water. The New Belgium Brewery in Fort Collins, Colorado, uses bacteria to clean its waste water, producing methane gas as a byproduct. While the brewery uses wind power for most of its power needs (about 85 percent), the methane gas from the waste-water clean-up kicks in the remaining 15 percent.

New Belgium also recaptures and reuses water, uses "green building" techniques in constructing its facilities, has a sustainability specialist on staff and follows the mantra of reduce/reuse/recycle as much as possible. Not only are these practices good for the environment, they’re good for the bottom line, too: the New Belgium Brewery claims to save $3,000 every month on its electricity bill.

For more information about microbial fuel cells, green technologies and other related topics, check out these great links:

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