In the world of wind turbines, size does matter. The rule is: The bigger the turbine, the more power it generates. However, colossal windmills are most suitable for remote and open areas—at sea, for instance—where there are powerful winds and no view to obstruct. Italian architect Renzo Piano mimicked nature to design a better solution: the Libellula (Italian for “dragonfly”), a small, efficient windmill anyone can place in his own backyard.

Before designing the rotor blades, Piano studied the flight technique of the dragonfly, one of the fastest and most efficient flying insects. The blades generate power from the slightest breeze, even air blowing just four miles an hour, making it effective almost all the time, not just during big blasts of wind. One Libellula generates enough power to run 15 households.

Because of the small size and the design of the Libellula—the windmill has only two blades instead of three—the turbine is less noticeable. At 65 feet tall, the Libellula is five times shorter than the average turbine found on wind farms. It was designed for the Italian energy cooperation ENEL and is being tested on the outskirts of Pisa, Italy.

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