Wind Generators Without Blades?
A New Type of Wind Generator with a Lot of Promise
Wind turbines are producing an ever-greater share of the world’s energy mix, especially of generated electricity. Wind generators continue to get taller and to realize greater production capacity, but these require more raw materials, stronger towers, bigger foundations, and frequent maintenance.
Vortex Bladeless Ltd., a Spanish startup company, is pioneering a radically different approach to harnessing the wind’s power. The idea came from the aerodynamic effect where wind creates spinning vortices as it passes close to buildings, bridges and other structures. This phenomenon is a big concern with architects and engineers, for in big winds, powerful oscillating motion can build and, in some cases, cause structures to collapse as with the Tacoma Narrows Bridge. Instead of dampening these forces, the Vortex company’s founders decided to try maximizing the aerodynamic instabilities and turbulences by getting these movements or swirls to harmonize and magnify the amount of energy that can be captured.
The vortex device is a slender, vertical, cylindrical mast made from a strong, lightweight composite of fiberglass and carbon fiber. The lightness allows for greater vibration and oscillation, yet it only needs a small foundation. It is not a turbine because it does not rotate. Two rings of repelling magnets at the base of the column give the oscillations a boost, regardless of wind speed, thus upping the efficiency. The vibrating, oscillating movement along the entire mast is converted into electricity by an alternator. The founders collaborated with scientists and engineers at Harvard and MIT to create the optimum design of the column.
A conventional wind turbine converts about 80-90 percent of the kinetic energy of its spinning blades into electricity. The bladeless vortex generator captures around 70 percent. This lesser efficiency is offset, however, by lower production cost, less than half; lower maintenance cost due to no gears, bolts, or shafts requiring lubricating; and more compact spacing. Since there is no “wake effect” as with regular wind turbines, they can be installed much closer together. The bladeless devices can be spaced half their height apart, whereas with traditional turbines, it is usually five times their total height. When concentrated, bladeless devices can provide maximum energy generation from each patch of real estate.
The company wants to concentrate, at least initially, on smaller generators for distributed locations, since they perform superbly, contrary to bladed turbines, near structures and in urban areas where winds are frequently turbulent. The prototypes have proved to be noiseless, again ideal near homes and office buildings. Some experts, however, think that tall masts will make considerable noise. Another big environmental advantage over regular turbines is that they won’t disturb wildlife. Birds and bats can avoid them easily while flying.
It is unlikely that Vortex wind power will replace wind turbines, but they have the potential to produce inexpensive renewable power where turbines can’t.