Canadians Generate Electricity from Tap Water

What started as a simple conversation between two University of Alberta engineering professors has led to the

discovery of a new way to harness electricity – from flowing tap water.

The Montreal Gazette reports that Dr. Daniel Kwok, who specializes in nanofabrication, and Dr. Larry Kostiuk, whose expertise is thermodynamics, combined their skills with two graduate students, Jun Yang and Fuzhi Lu, and built an apparatus that produces electricity by pushing water through a ceramic filter containing 10,000 tiny tubes. They call it an electrokinetic microchannel battery.

Their research, touted as the first new way of producing electricity in 160 years, was published by the London-based Institute of Physics’s Journal of Micromechanics and Microengineering. Their paper reveals a new source of clean, non-polluting electric power with a variety of possible uses, ranging from powering small electronic devices such as cellphones to contributing to a national power grid.

According to Kostiuk, the apparatus can produce up to 10 volts, but a current of only a few thousandths of an ampere. That’s not enough to run a light bulb. But it could be enough to power the so-called “lab-on-a-chip” instruments envisioned by those working in nanotechnology or on MEMS – micro-electronic mechanical systems, he said.

The project started soon after Kostiuk was appointed chair of the university’s department of mechanical engineering. When he 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, ‘That sounds like a battery to me,’ and I just paused and then realized what he said. 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 at using the phenomenon generated such a minute amount of energy the task was thought “impossible,” said Yang, a Ph.D. student 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 in 2002, wanted to try again. The idea, he says, was magnificent.

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 fourth member of the team, graduate student Lu, now has improved on the results detailed in the JMM paper, generating 20 times as much energy and illuminating LED lights.

A paper published in June 1964 (J.F. Osterle, Journal of Applied Mechanics) addressed the broad concepts of the phenomenon but not its applications.

“This new technology could provide an 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.”

Although the power generated from a single channel is extremely small, millions of parallel channels can be used to increase the power output.

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 their work. A patent application has been filed by the university to obtain broad, early protection of the invention, and the TTG is conducting an in-depth evaluation of the market.

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.