Beer Batteries: Microbial Fuel Cells Powered by Beer Waste

What if - you could brew your own beer, and while you were downing a tasty cold one, your television was powered by a home power generator run by the beer's waste water? You'd start drinking a lot more beer, wouldn't you?

This isn't a fairy tale or an alcohol-induced fantasy. The waste left over from beer manufacture can be used to charge a battery, and the resulting electricity can be used to power your home. Well, if you don't need a lot of power. Or if you don't drink too much beer.

Creating The Beer Battery

You might know it would be the Aussies who came up with this one. The beer battery is actually a microbial fuel cell, and was developed in a partnership between Foster's Beer, the University of Queensland in Australia, and the University of Ghent in Belgium (where the expertise is not beer but green power).

Microbial fuel cells work through the action of bacteria on organic matter. With the beer battery, bacteria break down the alcohol, starch, and sugar that is left over from the production of beer. This results in more bacteria, but also in electricity, carbon dioxide, and clean water - overall a very clean process. (Let's just dwell on the dream and not on the beer-battery induced global warming that carbon dioxide causes! In fact, just plant trees around your imagined beer battery. Yes, that's better.)

It turns out that brewery water is a perfect medium for the growth of this bacteria because it is completely biodegradable. Besides, the beer gets processed by the human body to create drunk people and - uh, never mind. Let's just say its products are also biodegradable.

Foster's Beer Battery: Australian for Electricity?

A prototype has been developed, but Foster's is building a new battery to install at their main brewery in Australia. It will hold 660 gallons of beer waste and bacteria, and will be able to produce 2 kilowatts of power daily - enough to power a home.

Okay, the average home brewery won't produce 660 gallons of beer waste. But the beer battery has an added advantage: it prevents all that water from being dumped into the sewers, where it can cause biological havoc by allowing unchecked bacterial and algae growth. Instead, the pure water that comes out of it can be recycled and used in the brewery again, and the electricity can simply be restored to the plant. Essentially, it's a waste purifier that also generates electricity.

The beer battery is a prototype for many similar devices that can be used in all organic industries, from fruit packing companies to slaughterhouses. The key is the usability of the organic waste by the bacterial substrate; anything the bacteria can eat can generate electricity, and the by-products, when you have the mix right, are water and carbon dioxide.

While the early microbial fuel cells will be used on an industrial level, it's hard not to imagine a version for home use. Instead of sending waste to a septic tank, it goes to the fuel cell. Food isn't wasted; even water used for cooking can just be dumped into the tank, where the busy little bacteria will do their job.

Or - remember the scene from Back to the Future, where the Professor fueled his car not with plutonium stolen from the Libyans, but with banana peels and leftover beer from the trash? Now that would be the ultimate triumph over oil.