Welcome to DU!
The truly grassroots left-of-center political community where regular people, not algorithms, drive the discussions and set the standards.
Join the community:
Create a free account
Support DU (and get rid of ads!):
Become a Star Member
Latest Breaking News
General Discussion
The DU Lounge
All Forums
Issue Forums
Culture Forums
Alliance Forums
Region Forums
Support Forums
Help & Search
General Discussion
In reply to the discussion: Wind Power Breakthrough [View all]OKIsItJustMe
(19,938 posts)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]
[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]
Edit history
Please sign in to view edit histories.
23 replies
= new reply since forum marked as read
Highlight:
NoneDon't highlight anything
5 newestHighlight 5 most recent replies
RecommendedHighlight replies with 5 or more recommendations
No problem...just take other people's money at gunpoint and give it to companies like Solyndra.
Minarchist
Dec 2011
#16
As opposed to Citigroup or BOA? Exxon Mobile? It's funny, in a telling way, to see what the target
BR_Parkway
Dec 2011
#19
When the GOP cuts off support for the US wind power industry, foreign companies will profit
jpak
Dec 2011
#6
"...direct-drive systems get disproportionately heavier as their power rating increases."
unkachuck
Dec 2011
#21