Tech Talk: The Advent of the Wind Lens

One of the most exciting aspects of green energy production is that, because it is a nascent industry, technological advances can occur at a relatively rapid pace.  One such advance, made possible by scientists at the University of Kyushu, could end up helping wind power take flight.

Computer simulation of proposed wind farm off the coast of Kyushu, Japan.  Source: http://polizeros.com/2010/08/02/wind-lens-turbines-could-triple-energy-output/ 

The "wind lens" is actually a series of modifications to the traditional wind turbine that help to increase airflow through the blades of the turbine, and subsequently, increase total power output.  The design works by encasing the blades themselves in an outer shell.  The shell is designed to create small vortices on the leeward side of the lens.  These vortices then create an area of low pressure where the wind exits the turbine (Fig 1).  Because pressures are lower where the wind exits the turbine, more air must move in to fill that area and attempt to achieve equilibrium; this effect causes wind speeds to increase in front of the blades and force more wind through the turbine.

Fig 1: Diagram of wind lens creation of low pressure system.  Source:  Kyushu University RIAM Wind Engineering Section Homepage. http://www.riam.kyushu-u.ac.jp/windeng/en_aboutus_detail04_02.html

The effects of this phenomenon, the researchers found, was to increase wind power by up to a factor of three from the "traditional" turbine design.  Thus, by upgrading wind turbines to wind lenses, existing wind farms could produce up to three times as much power, and energy needs could be satisfied with 1/3 of the space (Fig 2).  Now, due to additional materials usage, and the additional personnel required to retrofit existing structures and construct new fields, the initial startup costs for wind lens technology will be higher than that of traditional designs, but the long-term power advantages will be huge.  With wind lenses deployed in enough locations, the United States could see nearly 90% of its current energy usage accounted for by these wind farms.  Additionally, the wind lens is reported to be quieter than current windmills, and can be created in differing sizes to take advantage of microclimatic conditions in cities or countrysides.  

Fig. 2:  Comparision of results for wind generation between "conventional" turbines and wind lens technology.  Source:  Kyushu University RIAM Wind Engineering Section Homepage.  http://cleantechnica.com/2011/09/02/wind-lens-triples-turbine-output/

It's heartening to know that advances in green tech are rapidly closing the "cost gap"  between nonrenewable sources of energy and renewable, clean alternatives.  As costs fall, companies will be more inclined to pursue these sources to power their operations, since the social benefits combined with lower costs will be a boon for them both on their balance sheets, and in their public images.  Hopefully, proper subsidies and grants will be forthcoming for this technology in the coming few years, so that construction will be initiated in a timely manner, and the transformation of the world to a clean energy society can continue.