Schooling Windmills





The take home is that if we sitewindmills in a pattern conforming to schools of fish, we can increase actualenergy density by ten fold.  There areplenty of locales were this will be important. It certainly makes a landowner happy as he is looking at a ten foldincrease in rentals.

Thus the established wind farminfrastructure will be able to sustain a tenfold increase in production withoutadding new projects.

It is nice to see we even havefield confirmation already.

Obviously, the best thing to dois optimize those well away from living quarters to avoid the noise pollutionproblem which is likely to become a bigger thorn as we progress.

Know the Flow: How Jellyfish Can Improve Wind Farms

The engineer and recent MacArthur "genius" grant winnerthinks we have much to learn from the humble jellyfish



By Michael Moyer  | December 15,2010 | 0


Name: John Dabiri

Ttile: Associate professor of aeronautics and bioengineering,California Institute of Technology  2010MacArthur fellow Location: Pasadena, Calif.

What do you do every day? Quite a few different things. On a given daywe could be working on wind energy or working with the navy on underwatervehicles. We have, in our laboratory, live jellyfish in the upstairs labs and,downstairs, robotic vehicles that we design. We study biological systems andtry to steal ideas from nature to apply to technology.

Does the navy want a submarine that looks like a jellyfish? Our designsdon’t look like robotic jellyfish per se. We take the existing platforms thatthe navy uses—the propeller-driven vehicles—and try to modify them to createthe flows that we see in jellyfish.

Something like putting a spoiler on the back of a race car? That’sprobably a good analogy—one of these things that modify an existing system toenhance its performance. Certainly we could imagine building things that weremore like jellyfish or squid in their nature. But what we’re really waiting foris for the materials scientists to come up with something that provides theflexibility that you would want and at the same time has the strength and theresilience that you would expect from a vehicle that’s going to be in the waterfor many years at a time.

You recently showed that studies of fish schooling can aid wind-farmdesign. How does that work? The challenge with existing horizontal-axis windturbines is that they need a lot of space; you have to separate the turbines sothat their wakes don’t interact. So we started to explore vertical-axis windturbines, which rotate on a vertical pole and can take wind from any direction.As I was starting to model the equations for the wind field around a turbine,it was sort of one of these eureka moments—I realized that they were verysimilar to the equations that we saw previously studying fish schooling. Fisharrange themselves to minimize the amount of energy that’s required for thegroup to go from point A to point B. Our aim would be to try to maximizethe amount of energy that is extracted from these vertical-axis turbines.

So in your model, you are able to get 10 times higher energy density?Not just in our models. Over this past summer we have done small field tests,and the predictions of the model have been borne out.

Sounds like you’ve got your first business. [Laughs] I think what we’rereally aiming to do is to change people’s minds about wind energy. People callit the most mature of the renewable energy technologies, where the future is:Can we build them larger? Can we put them offshore? But there are somefundamental advances that can be made if we reconsider whether the three-bladedturbine is the optimal solution.

If everyone could know one thing about your work, what would it be?Technology is ever evolving. While there’s a lot of opposition to the currentplatform for wind energy, there are better options to come. There’s no need tosettle just yet.

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