For the past 30 years we have had the same strategy for building wind farms, making windmills as large as possible and spacing them far apart to avoid them interfering with one another aerodynamically. So it might come as a bit of a surprise to hear that researchers from the California Institute of Technology have come up with all but the opposite of the current approach to wind farm design.
Vertical-axis wind turbines
The new design that is described in the Journal of Renewable & Sustainable Energy entails vertical-axis wind turbines (VAWTs) that can be placed much closer together than conventional propeller-style turbines. The VAWTs access near-ground winds at only 30 feet. Wind energy at this height is less abundant, but the new design can harness it more efficiently.
What’s new about the design?
So you might wonder: VAWTs have been around for a while and haven’t really proven their worth, what has changed? First off the new generation of VAWTs is much less prone to structural failures due to fatigue than their predecessors. Second, since the new Caltech design puts the turbines closer together, it doesn’t rely as heavily on individual turbine efficiency as other designs, which is a good thing since VAWTs are less efficient individually than propeller-style turbines.
The real benefits this new approach offers are a simpler design consequently lowering costs of operation and maintenance and a lower profile with less visual and acoustic problems as well as a decrease in bird and bat impacts, not to mention the decrease in required space.
Mission not yet achieved
The goal of the research is breaking the wind energy status quo by reducing its cost thus making it less dependent on subsidies. A recommendable objective that has been off to a great start but still needs a lot more research. However if the research team manages to scale up their field demonstration and improve upon the off-the-shelf wind turbine designs used for the pilot study, this radical new design might just be what wind energy needs to make it truly sustainable.
© Jorn van Dooren | www.bitsofscience.org