In March 2011, Siemens launched the SWT-2.3-113 gearless wind turbine with a rating of 2.3 MW and a rotor diameter of 113 meters for low to moderate wind conditions. The company also expects to launch a new 6-MW direct drive wind turbine by the end of the year, which will be particularly suitable for large offshore wind power plants.
Siemens Energy has been awarded another order from Minnesota Power for 35, 3-MW SWT-3.0-101 direct drive wind turbines for its Bison 2 wind energy center near Center, North Dakota. The scope of supply for the wind-power plant includes transportation, erection, and commissioning of the 35 wind turbines, as well as a three-year service and maintenance agreement. Deliveries of the wind turbines will commence in August 2012, and the wind power plant is scheduled for commissioning by the end of 2012.
This order is the third for Siemens direct drive wind turbines in the U.S., including Minnesota Power’s Bison 1 North Dakota and Oklahoma Gas & Electric’s Crossroads Oklahoma wind power plants. “Our direct drive turbines have only half the parts required for a conventional geared wind turbine and a significantly smaller number of moving parts, allowing for increased output and improved maintainability,” says Jan Kjaersgaard, VP and general manager of Siemens’ Americas Wind Power business.
The SWT-3.0-101 direct-drive wind turbine has a rated power output of 3 MW, a rotor diameter of 101 m, and an innovative permanent magnet generator. The first prototypes of the SWT-3.0-101 have been running for more than a year and are meeting all expectations in terms of reliability and performance, according to the company.
Siemens
http://www.siemens.com/energy
Filed Under: Construction, News, Turbines
Why do we not use electro hydrolic converters with constant velocity transmissions?
“Would you rather have a V-8 in your car, or a one-lunger of equal horsepower?”
Crummy analogy. Is it necessary to explain why? (Think much smaller explosions, more closely timed.)
The weak point in wind turbines is the gear train. The bearing surfaces wear out. Energy is lost.
Permanent magnet materials can and will be recycled.
And I’d question the weight claim. My guess is that gearless turbines weigh less.
Regarding the number of parts in direct drive vs. geared drive, the best geared drive turbine to use for comparison would be the DeWind 8.2. Direct drive turbines require power electronics, the DeWind 8.2 does not. How many parts does an inverter have? Thousands, none of which are present in the DeWind design.
If only moving parts are considered, and ignoring the fact that there is constant movement on the molecular scale in many of the parts of an inverter, a geared turbine will have more moving parts than the direct drive type. So would a V-8 engine compared to a single cylinder engine. Would you rather have a V-8 in your car, or a one-lunger of equal horsepower?
The size, weight, expense, difficulty in handling and sealing from the weather, and the requirement for permanent magnets made from rare earth metals make the direct drive generator an absurdity, since far better arrangements have already been proven. However, they all require geared drives.
Before many years have passed, the folly of using direct drive generators in wind turbines will become evident.