Wind Power Breakthrough

[FourScore]

Tue Dec 27, 2011 at 08:21 AM PST
Wind Power Breakthrough
by LeftOfYouFollow

Electrical engineers all over the country must be slapping themselves in the forehead in a "Why didn't I think of that?" moment after the announcement of an elegant high-tech fix for a persistent wind energy efficiency problem that has plagued the electric wind turbine industry and retarded the growth of wind farms. The story is here of an ingenious design that, in effect, replaces heavy, breakdown-prone and expensive wind turbine transmission systems with small, light weight computer controlled electronic circuits while increasing efficiency and maximum output at the same time. The story in MIT's Technology Review put it thus:

The generator works on the same principles as many ordinary generators: magnets attached to a rotating shaft create a current as they pass stationary copper coils arrayed around the shaft. In ordinary generators, all of the coils are wired together. In ExRo's generator, in contrast, the individual coils can be turned on and off with electronic switches. At low wind speeds, only a few of the coils will switch on--just enough to efficiently harvest the small amount of energy in low-speed wind. (If more coils were active, they would provide more resistance to the revolving magnets.) At higher wind speeds, more coils will turn on to convert more energy into electricity.

Conventional generators operate at optimum efficiency only at a particular speed, with efficiency dropping off rapidly as that speed increases or decreases. This has always been a problem for wind farms and has been addressed with mechanical transmissions to mediate turbine speed and variable pitch technology for the wind foils, all adding weight, complexity and expense to the design. The new generators will still need variable pitch, but the design totally eliminates transmissions and allows the turbine to operate at ambient wind speeds and remain efficient.

After the fact the new variable speed generator design almost seems obvious, given the physics, but nobody else apparently thought of it first, particularly the big players like Siemans, GE and Westinghouse. Regardless, lighter weight, less mechanically complex, easier to maintain, more efficient and higher output wind turbines look like a heck of a breakthrough...

http://www.dailykos.com/story/2011/12/27/1049178/-Wind-Power-Breakthrough?via=siderec