Researchers generate electricity from tap water

What started as a simple conversation between two University of Alberta engineering professors has led to the first discovery of a new electricity source in more than 160 years--from flowing tap water.

October 20, 2003 - What started as a simple conversation between two University of Alberta engineering professors has led to the first discovery of a new electricity source in more than 160 years--from flowing tap water.

The U of A research, published today by the Institute of Physics journal, Journal of Micromechanics and Microengineering, reveals a new method of generating electric power by harnessing the natural electrokinetic properties of a liquid such as ordinary tap water, by pumping fluids through tiny microchannels. A team of researchers and students, led by Dr. Daniel Kwok and Dr. Larry Kostiuk, has created a new source of clean non-polluting electric power with a variety of possible uses, ranging from powering small electronic devices such as cell phones to contributing to a national power grid.

The project started soon after Kostiuk was appointed chair of the university's Department of Mechanical Engineering. When Kostiuk made his rounds to learn what his colleagues were studying, he listened to Kwok describe his work with electrokinetics--the science of electrical charges in moving substances, such as water.

In that meeting Kwok explained how, when water travels over a surface, the ions that it is made up of "rub" against the solid, leaving the surface slightly charged. "Then Larry said to me, 'well that sounds like a battery to me,' and I just paused and then realized what he said," said Kwok. "This shows the importance of interdisciplinary work--sometimes we focus so much on our research that we aren't able to take a step back and see what others can see."

Initial efforts generated such a minute amount of energy the task was thought "impossible," said Jun Yang, a graduate student working towards his PhD in mechanical engineering who designed the experiment at Kwok's request.

But Yang, who came to the U of A from the Beijing Institute of Technology two years ago, wanted to try again. The idea, he says, was magnificent.

"This phenomenon has been known for several hundred years," said Yang. "But no one had ever thought about it in this way."

Yang and Kwok exchanged ideas on ways to increase the amount of energy generated by increasing the number of channels they forced water through. The team, which includes graduate student Fuzhi Lu, has been able to improve on the results detailed in their research paper, generating 20 times as much energy and illuminating LED lights by exploiting the coupling between electrokinetic phenomena and the hydrodynamics of liquid flow.

"This discovery could be a new alternative energy source to rival wind and solar power, although this would need huge bodies of water to work on a commercial scale," said Kostiuk. "Hydrocarbon fuels are still the best source of energy but they're fast running out and so new options like this one could be vital in the future.

"This technology could provide a new power source for devices such as mobile phones or calculators which could be charged up by pumping water to high pressure."

Although the power generated from a single channel is extremely small, millions of parallel channels can be used to increase the power output. More work will be needed to further understand this new means to produce power.

The discovery has made headlines around the world. One reason for the interest in the development is that there are a very limited number of ways to generate electricity. Most methods were discovered in the early 1800s. Kwok and Kostiuk's work represents the first new discovery to generate electricity since 1839, when Sir William Robert Grove, considered the father of the fuel cell, developed two electrochemical batteries. One was used in telegraph operations and the second was the forerunner of modern fuel cells. The same year, Edmond Becquerel discovered how to generate electricity from sunlight.

Dr. David Lynch, Dean of the Faculty of Engineering, praised the team for rigour and creativity. "The discovery of an entirely new way of producing power is an incredible fundamental research breakthrough. It has been more than 160 years since the last such fundamental discoveries that have now led to the current applications associated with solar cells and fuel cells. This ground-breaking discovery of an electrokinetic effect that can generate electricity could be equally revolutionary," he said. "It will earn these engineering researchers and the University of Alberta a place of prominence in scientific journals and textbooks for decades to come and electrokinetic cells may find significant applications in numerous commercial areas."

The environmental benefit of clean energy conversion using safe, renewable materials is motivating the team to explore how their prototype device may be developed into a battery for commercial use. The inventors are working with the U of A's Technology Transfer Group (TTG) to develop a commercialization strategy for the work. A patent application has been filed by the university to obtain broad, early protection of the invention. The TTG is conducting an in-depth evaluation of the market opportunities.

The research was funded in part by a Natural Sciences and Engineering Research Council of Canada (NSERC) grant. Dr. Kwok's work is also supported by the Alberta Ingenuity Fund.

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