Vortex-Bladeless Wind Generator. "Using the scientific principles of natural frequency and vorticity, the turbine oscillates in swirling air caused by the wind bypassing the mast, and then builds exponentially as it reaches the structure’s natural resonance. It’s a powerful effect that famously caused the collapse of the Tacoma Narrows Bridge
in 1940, footage of which inspired Yáñez to try to build a structure to harness this energy rather than prevent it."
(1 June 2015, theguardian.com)