Schooling fish and their interaction with one another has inspired a Caltech professor to rethink how wind energy can be created.
[social_buttons]Head of Caltech’s Biological Propulsion Laboratory John Dabiri and two of his graduate students have turned to schools of fish to further our knowledge of how wind turbines work best and how to combat the lack of space we have for the traditional horizontal-axis wind turbines most commonly seen across the landscape.
“I became inspired by observations of schooling fish, and the suggestion that there is constructive hydrodynamic interference between the wakes of neighboring fish,” said Dabiri, associate professor of aeronautics and bioengineering at Caltech. “It turns out that many of the same physical principles can be applied to the interaction of vertical-axis wind turbines.”
“Propeller-style wind turbines suffer in performance as they come in proximity to one another,” says Dabiri, which forces any significant generation of power to happen over larger and large spaces. This can be a significant problem considering the sometimes total lack of space to put a worthwhile amount of turbines.
But Dabiri has combined the principles supplied by schooling fish with vertical-axis turbines.
Relative newbies to the wind-generation field, vertical turbines don’t have propellers, but rather use a vertical rotor instead. As a result they can be placed on smaller plots of lands in conversely denser patterns. Dabiri, along with Caltech graduate students Robert Whittlesey and Sebastian Liska, are beginning work on determining how best to use this new technology.
Traditional horizontal turbines all have to be turning the same direction, and be placed a significant distance away from one another. However while watching the vortices left behind by fish swimming in a school Dabiri noticed that some vortices rotated clockwise while others rotated counter-clockwise. Dabiri plans to take this idea and apply it to alternating the rotation of vertical-axis turbines in close proximity with one another, and test whether there is any improvement in efficiency.
The second observation that Dabiri made while watching the fish was that the vortices form a “staircase” pattern, contradicting the neat rows that horizontal wind turbines are organized in.
Dabiri believes that up to ten times the amount of energy currently generated can be produced by identifying the ideal placement and pattern of turbines. Dabiri’s results have been so striking that not only are they constructing a field demonstration on what will be called the Caltech Field Laboratory for Optimized Wind Energy (FLOWE) but Windspire Energy are providing three of the six turbines.
“This leading-edge project is a great example of how thinking differently can drive meaningful innovation,” says Windspire Energy President and CEO Walt Borland. “We are very excited to be able to work with Dr. Dabiri and Caltech to better leverage the unique attributes of vertical-axis technology in harvesting wind energy.”
“This project is unique in that we are conducting these experiments in real-world conditions, as opposed to on the computer or in a laboratory wind tunnel,” says Dabiri. “We have intentionally focused on a field demonstration because this can more easily facilitate a future expansion of the project from basic science research into a power-generating facility. Our ability to make that transition will depend on the results of the pilot program.”
“Our goal is to demonstrate a new technology that enables us to extract significantly more wind energy from a given parcel of land than is currently possible using existing methods,” says Dabiri. “We want to take advantage of constructive aerodynamic interference between closely spaced vertical-axis wind turbines. Our results can potentially make better use of existing wind farms, allow for wind farms to be located closer to urban centers—reducing power transmission costs—and reduce the size of offshore installations.”
Image Source: otolithe (olivier roux) via flickr/CC license