Seeking a new way to make electricity, scientists at the Iowa State University have developed a tree-like device whose artificial leaves sway in the wind to generate electricity.
The device's design was pioneered by Michael McCloskey, associate professor of genetics. He said conceptually it is not a replacement for wind turbines.
However, in the long term, the technology can create a specialized market for small machines that can convert wind energy into electric power.
Off Grid Production
"The possible advantages here are aesthetics and its smaller scale, which may allow off-grid energy harvesting," McCloskey said.
He said the effort has been to generate useful amounts of electrical power from a plant-like object. The answer is positive and the idea needs further development.
McCloskey cited the example of Las Vegas where telecom towers have been designed in the shape of trees with the leaves hiking the aesthetic appeal. The experiment shows energy can be tapped from the leaves of such objects as well.
The study published in PLOS ONE explains the team's foray into biomimetics, which is about applying artificial means to ape natural processes. It has gained good traction in many fields including computers and nanoscience.
Featuring a metallic trellis, the prototype has plastic flaps fashioned as leaves of cottonwood.
Curtis Mosher, co-author and associate scientist at Iowa State, said the prototype has the potential to be scaled up as an artificial tree by adding more leaves that can produce wind-based electricity.
He said more work needs to be done in commercializing the concept.
How Does It Work?
In terms of operation, when moved by air, electrical charge is released by plastic strips stored within the leaf stalks under the piezoelectric effect. The reason for choosing cottonwood leaves was obvious: the flat leaf stalks can accentuate oscillation of blades thanks to the action of the strips.
According to genetic professor Eric Henderson, who was part of the research team, biomimetic trees running household appliances as a futuristic technology looks bright.
He said biomimetic technology can carve a good market when demand builds up for small amounts of wind energy without needing the help of towers or turbines.
McCloskey said the project's vision of doing away with towers and turbines was behind the initiative in developing an alternative to mechanical-to-electrical transduction where wind energy converts into usable electricity.
One constraint seems to be the piezo method used by researchers not proving adequate to scale up the efficiency required in competing in the market.
Another transductive option to generate electricity was triboelectricity, where friction between dissimilar materials generates charge. But McCloskey said producing a practical device for it is a bit hard.
Wind Energy Outlook
Meanwhile, the outlook on wind energy from the Department of Energy's annual report is upbeat. It says wind power capacity in America will double 152 gigawatts by the year 2023 from the present 76 GW.
Improvement in turbine technology will tap steadier winds, and productivity in wind power will double. That means the wind will be supplying 12 percent of the U.S. electricity by 2023,with the cost and better performance of wind power boosted by recent technological improvements.
Thanks to rising competitiveness, wind deployment will be up and go beyond 140 GW by 2023.