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

[Scuba]

1. We should be pouring money into R&D on a bunch of energy fronts. n/t

[liberal N proud]

4. But we have an economy built on bombs

The congress will not allow any development that would threaten the military industrial complex or the oil companies.

[Minarchist]

5. What's stopping you from doing just that?

http://www.greenchipstocks.com/

[Minarchist]

16. No problem...just take other people's money at gunpoint and give it to companies like Solyndra.

It might not do any good, but at least you had good intentions.

[BR_Parkway]

19. As opposed to Citigroup or BOA? Exxon Mobile? It's funny, in a telling way, to see what the target

of some people's outrage is. Especially when it's been so focused by hate radio

[Creideiki]

22. Libertarians are so cute

In that, "I outgrew that in 8th grade sort of way."

[knowbody0]

2. that's so cool

[Politicalboi]

3. Couldn't the same technology be used in cars

But using the motion of the tires rotating and use that energy to feed back into the battery.

[TheWraith]

8. That's what regenerative braking on hybrids and electric cars is. nt

[NMDemDist2]

9. that's what my new car does

doesn't take the place of the motor, but helps with acceleration and gas mileage

http://www.democraticunderground.com/?com=view_post&forum=1127&pid=1892

[jpak]

6. When the GOP cuts off support for the US wind power industry, foreign companies will profit

from this.

Since the late 1970's the GOP has done it's best to kill off the US renewable energy industry.

No doubt they will succeed again - and we will be importing new turbines using this technology...

rather than building them ourselves...

yup

[B Calm]

7. So when do we hand over this new technology to China?

[slackmaster]

10. Rec for having both "Wind" and "Break" in the title

Interesting read.

[greiner3]

11. "0. Wind Power Breakthrough;"

And here I thought I'd see a picture of one of the Republican Presidential debates.

[Control-Z]

12. But will we take advantage of this breakthrough?

I highly doubt it. I'm becoming a Debbie Downer when it comes to renewable energy efforts by the US.

[OKIsItJustMe]

13. This “breakthrough” is at least 3 years old…

http://www.technologyreview.com/energy/21666/

[font face=Times,Times New Roman,Serif][font size=5][h2]Better Wind Turbines[/h2][/font]
[font size=4]A more efficient generator could convert more of the wind's energy into electricity.[/font]

Thursday, November 13, 2008
By Kevin Bullis

[font size=3]ExRo Technologies, a startup based in Vancouver, BC, has developed a new kind of generator that's well suited to harvesting energy from wind. It could lower the cost of wind turbines while increasing their power output by 50 percent.

The new generator runs efficiently over a wider range of conditions than conventional generators do. When the shaft running through an ordinary generator is turning at the optimal rate, more than 90 percent of its energy can be converted into electricity. But if it speeds up or slows down, the generator's efficiency drops dramatically. This isn't a problem in conventional power plants, where the turbines turn at a steady rate, fed by a constant supply of energy from coal or some other fuel. But wind speed can vary wildly. Turbine blades that change pitch to catch more or less wind can help, as can transmissions that mediate between the spinning blades and the generator shaft. But transmissions add both manufacturing and maintenance costs, and there's a limit to how much changing the blade angle can compensate for changing winds.

ExRo's new design replaces a mechanical transmission with what amounts to an electronic one. That increases the range of wind speeds at which it can operate efficiently and makes it more responsive to sudden gusts and lulls. While at the highest wind speeds the blades will still need to be pitched to shed wind, the generator will allow the turbine to capture more of the energy in high-speed winds and gusts. As a result, the turbine could produce 50 percent more power on average over the course of a year, says Jonathan Ritchey, ExRo's chief technology officer. Indeed, in some locations, the power output could double, says Ed Nowicki, a professor of electrical engineering at the University of Calgary, who has consulted to ExRo.

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. The switches can be thrown quickly to adapt to fast-changing wind speeds.

…[/font][/font]

[unkachuck]

15. "...the design totally eliminates transmissions..."

....wouldn't you still need a transmission to step up the blades' rpm for generator? If not, wouldn't the generator grow in size in order to be able to produce power at low blade rpm?

....I can see by switching the generators' coils/load to track the blade output more efficiently could reduce the transmission load at low and intermediate rpm, but wouldn't you still need a transmission?

[Gregorian]

18. Check out the link in my post below

The solution is that they can stack sections like pancakes until they have as much generating power as needed. It does eliminate the need for transmissions. I find it really disturbing that this has been overlooked for so many years. Our interests obviously lie in other areas.

[unkachuck]

21. "...direct-drive systems get disproportionately heavier as their power rating increases."

....I see what you're saying about the stacked rotor/stator stages brought online incrementally but those stages are adding more weight while 60hz for the grid still has to be maintained....

....it'll be interesting to see how this develops....reply title and more below

http://www.technologyreview.com/energy/37983/

[Gregorian]

17. Here's a good explanation of how it works

http://peswiki.com/index.php/Directory:ExRo_Technologies#How_it_Works


It's not as trivial as it seems. 12 years went into designing it. It is somewhat puzzling how such a basic design could be overlooked all of these years. The way I seee it is that essentially the generator is overloaded with resistance, but only partial resistance is utilized where it is needed.

The big deal is that it allows for direct drive that works at slow rpm's.

[paparush]

20. What if Solar (alternative) was subsidized like fossil fuel

http://www.greenerideal.com/alternative-energy/solar-energy/8563-what-if-solar-was-subsidized-like-fossil-fuels/

[Motown_Johnny]

23. an elegant solution

gotta love it