Researchers from California Institute of Technology have been conducting a field tests at an experimental two-acre wind farm in northern Los Angeles County. The farm, known as the Field Laboratory for Optimized Wind Energy (FLOWE), houses 24 10-meter-tall, 1.2-meter-wide vertical-axis wind turbines (VAWTs) - turbines that have vertical rotors.
Most modern wind farms employ horizontal-axis wind turbines (HAWTs), the standard propeller-like monoliths. In such farms, the individual turbines have to be spaced far apart – not just far enough that their giant blades don’t touch. With this type of design, the wake generated by one turbine can interfere aerodynamically with neighboring turbines, with the result that "much of the wind energy that enters a wind farm is never tapped," says John Dabiri, a Caltech professor of aeronautics and bioengineering.
VAWTs can be positioned very close to one another, which lets them capture nearly all of the energy of the blowing wind and even wind energy above the farm. Having every turbine turn in the opposite direction of its neighbors, the researchers found, also increases their efficiency, perhaps because the opposing spins decrease the drag on each turbine, allowing it to spin faster. Dabiri got the idea for using this type of constructive interference from studies of schooling fish.
In the video below, Dabiri discusses his wind research and aerial footage is shown of the facility.