Brewery wastewater is surprisingly great for making batteries

A pint of your finest AAAle please, barkeep

Breweries produce a lot of wastewater, which is expensive and a pain to deal with. But now, biotechnologists at Colorado University, Boulder, have found a new use for it - making energy storage cells.

“Breweries use about seven barrels of water for every barrel of beer produced,” said Tyler Huggins, a graduate student in CU Boulder’s Department of Civil, Environmental and Architectural Engineering and lead author of the paper describing the research. “And they can’t just dump it into the sewer because it requires extra filtration."

Win-win situation

But that wastewater is perfect for cultivating a fast-growing fungus called Neurospora crassa, and the fungus produces the carbon-based materials useful in lithium-ion battery electrodes. In the process, it cleans the wastewater - making the whole endeavour a win-win situation for both the breweries and the lab. 

“The novelty of our process is changing the manufacturing process from top-down to bottom-up,” said Zhiyong Jason Ren, an associate professor in CU Boulder’s Department of Civil, Environmental and Architectural Engineering and a co-author of the new study. “We’re biodesigning the materials right from the start.”

A big opportunity

Huggins and one of his colleagues, study co-author Justin Whiteley, have filed a patent for the process and formed a company to commercialise the technology. “We see large potential for scaling because there’s nothing required in this process that isn’t already available,” said Huggins.

Ren, who intends to continue studying the mechanisms and properties of the fungus, said: "It’s great to see students succeeding and creating what has the potential to be a transformative technology. Energy storage represents a big opportunity for the state of Colorado and beyond.”

Duncan Geere is TechRadar's science writer. Every day he finds the most interesting science news and explains why you should care. You can read more of his stories here, and you can find him on Twitter under the handle @duncangeere.