Blade-less Wind Turbines
Wind energy plays a pivotal part in global renewable energy framework. Due to its free-abundant availability, it has always been a viable option as an alternate power source. Recently, the adoption of wind energy has gained momentum in several countries and its environmental viability will increase its use and reliance in years to come.
With larger turbines (to avail maximum benefits), transportation is increasingly challenging because of the size of the components. Individual blades and tower sections often require specialized trucks and straight, wide roads. Generators and gearboxes sitting on support towers, 100 meters off the ground, can weigh more than 100 tons. As the weight and height of turbines increase, the materials & construction cost of supporting tower increases. Also, the cost of maintaining components are cutting into the efficiency benefits of larger turbines.
A Spanish startup Vortex Bladeless has developed turbines that harness vorticity, the spinning motion of air or other fluids. When wind passes one of the cylindrical turbines, it shears off the downwind side of the cylinder in a spinning whirlpool or vortex. That vortex then exerts force on the cylinder, causing it to vibrate. The kinetic energy of the oscillating cylinder is converted to electricity through a linear generator similar to those used to harness wave energy.
David Yá?ez, one of the company’s co-founders, first came across the concept as a student studying the collapse of the Tacoma Narrows Bridge in Washington. The bridge collapsed in 1940 due to excessive vibrations formed by the spinning motion of wind as it blew past the bridge and is a textbook engineering failure. Yá?ez, however, learned a different lesson. “This is a very good way to transmit energy from a fluid to a structure,” he says.
Vortex claims that energy produced by its turbines will cost around 40 percent less than energy made from today's wind turbines and a large part of that cost reduction comes from maintenance as the Vortex doesn't have moving parts or gears, it should last longer and won't require periodic lubrication.
The simpler design also means that manufacturing costs are about half that of a traditional wind turbine (those massive blades are expensive). As per Vortex, its blade-less design captures around 30 percent less energy than a regular turbine, but it's possible to fit more of the "silent" Vortex models in the same area.
Vortex is working on its "Mini," a 41-foot model that should be ready for commercialization in 2016; while a larger, industrial model is in the works for 2018.
As is the case with any new technology, Vortex too has challenges to overcome viz. increasing efficiency, inherent complications of fluid dynamics involved in capturing higher-wind velocity, etc. But the future of Wind Energy, as an effective source of power is definitely bright, be it the Vortex Bladeless, or Makani Power's Energy Kite or Professor John Dabiri's work on Vertical Axis turbines (& challenging the concept of spacing wind turbines far apart)