DeWind Offers Simplified Drive Train, No Power Conversion Electronics

Wind turbine manufacturer, Dewind Inc.,Irvine, CA, (formerly EU Energy (EU)), a subsidiary of Composite Technology Corporation (CTC) (OTC BB: CPTC) has taken a different approach to its drive train technology than other manufacturers. From the start, the heart of the drive has been a trend-setting combination of a double-fed asynchronous generator and a pulse-width modulated IGBT type inverter. In October 2005, EU and Voith Turbo of Germany announced a joint co-operation agreement for the development of the WinDrive for use in a 60 Hz DeWind D8.2 wind turbine aimed at the US market. The WinDrive hydro-dynamic torque converter functionally decouple the mechanical gearbox output shaft from the generator input shaft causing drive train vibrations to be dampened and shocks and peak loads to be substantially reduced, and the power conversion electronics to be eliminated.

The first 2 megawatt DeWind D8.2 wind turbine incorporating the WinDrive technology is now fully operational and has been producing electricity since the 6th of January, 2007 at the DEWI-Offshore and Certification Centre GmbH (DEWI-OCC) test site in Cuxhaven, Germany.

CTC announced on July 16, 2007 that DeWind received certification of the 50 Hz version of their 2 Megawatt D8.2 wind turbine from DEWI-OCC according to the Deutsches Institut für Bautechnik (DIBt) standards

In June 2006 US-based Composite Technology Corporation (CTC) announced the completion of the acquisition of EU Energy Ltd., the owner of the EU Energy and DeWind group of companies.

DeWind Inc., produces sells, and licenses the DeWind series of wind energy turbines including the 50Hz D8 rated at 2 megawatts (MW) and the 50Hz D6 rated at 1.25 MW, both noted for their reliability. In 2007, the first novel D8.2 turbines rated at 2 MW are to be delivered to North American customers from assembly operations at TECO Westinghouse Motor Company in Texas. The DeWind D8.2 uses a Voith WinDrive® and a synchronous generator connected directly to the grid to produce power at 13,800 Volts, without the use of power conversion electronics. The WinDrive® is a hydrodynamic torque converter that allows the variable speed of the wind to be converted to a constant speed allowing clean power to be delivered to the grid. This proven technology has achieved MTBFs in excess of 30 years in the gas compressor industry. The DeWind D8.2 is available in both a 60Hz and 50Hz version.

In October 2005, in an exclusive arrangement with Voith AG, Dewind acquired its Vorecon technology WinDrive hydro-dynamic torque converter, effectively a variable speed transmission, in order for its D-8 series to incorporate this interface between the blade rotation gearbox and a synchronous generator with an output of 13.8kv at the proper frequency. The result is the new 60Hz 2 megawatt DeWind D8.2 for the U.S. and Canadian market and the new 50Hz 2 megawatt DeWind D8.1 for the European market; both of which are expected to outperform the competition due to the proven reliable gearbox and torque converter that enables stable generator output with direct connection to the grid without the need for expensive or problematic power conversion electronics.

The WinDrive uses the same mechanism as is used in Voith's huge gas compressors, where it has demonstrated a 39-year mean time before failure (MTBF), twice the life expectancy of an average wind turbine. In the future this technology offers the potential for drive train weight reductions of up to 20% and nacelle weight reductions of up to 10%.

In March 2007 DeWind, Inc., received an order from XRG Development Partners LLC (XRG) for the delivery and service of 18 DeWind 2 megawatt D8.2 wind turbines. This will be the first wind farm to use the D8.2 equipped with the Voith WinDrive® which allows high voltage power to be sent directly to the grid without the necessity for power conversion electronics. The turbines will be manufactured at the TECO Westinghouse facility in Texas. The contract value is in excess of $40 million and the turbines are scheduled for delivery in late 2007 to XRG’s project site in Minnesota. This is the initial order for what both companies expect to be a long term relationship for as many as 750 turbines over the next five years.

CTC announced the completion of the acquisition of EU Energy Ltd., (formerly EU Energy plc), on July 5, 2006, the owner of the EU Energy and DeWind group of companies. EU Energy was valued at $60.7 million and, by agreement with its shareholders, CTC has paid for the acquisition by issuing 39,169,670 shares of restricted common stock in exchange for the entire share capital of EU Energy taking into account the value of CTC common stock at its close on May 11, 2006.

With the acquisition, CTC benefited from a number of turbine reserve agreements with 5 separate North American wind farm operators signing between February and June 2006 for the acquisition of its new DeWind 2 megawatt D8.2 wind turbines, specially designed for the North American market. These agreements are for the delivery of a total of 1313 turbines through 2012 and represent anticipated revenue of $2.845 billion over the same period. Deliveries are scheduled to commence, 12 months of the date of acquisition, with approximately 100 committed for delivery in 2007 and a further 50 reserved.

By virtue of the acquisition CTC also acquired non-exclusive license agreements with two companies to produce and sell the existing 1.25 megawatt D6 turbines in China and a third non-exclusive license agreement with another Chinese company to produce and sell the existing 2 megawatt D8 turbine in that market. CTC will continue negotiations based on a signed Letter of Intent regarding the creation of a joint venture to produce the D6 turbines in India.

Although fixed-speed/two-speed turbines can be sold without restrictions in US wind market, variable-speed wind system suppliers like DeWind potentially face a problem. The reason is that most of these technologies violate General Electric‘s so-called ‘variable speed patent’ for the US market which focuses on variable speed power electronics. In October 9, 2006 EU Energy licensed certain patents from GE Energy’s wind business (GE Energy). While EU's range of wind turbines employ their own technology and designs, the license from GE Energy will permit EU to continue to sell its traditional model DeWind D6 and D8 wind turbines incorporating the use of conventional power conversion electronics in markets where the GE patents are applicable. The DeWind D6 is available in 50Hz and 60Hz worldwide and the DeWind D8 available in 50Hz worldwide.

Most of the information contained in this post was derived from Composite Technology press releases, the Eu Energy website and from a post at Renewable Energy World.

Comments

[Yosef]

As a mechanical engineer, I find this encouraging: I used to think that more and more systems go electric, and here's some movement in the opposite direction. But why?

One reason would be the US patent - a need to do things differently. But that would mean that this turbine is less possibly efficient than GE competition.

Inverter prices are $0.709 per continuous watt [1], so I guess the mechanical system has the potential of being cheaper. As the article states, it also has the potential for reducing system weight. One more benefit is proven reliability - which sounds strange, when usually you see reliability improve as the number of moving parts drops, but I won't argue with the numbers.

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[1] http://www.solarbuzz.com/Inverterprices.htm

[PM]

Does anyone know how this system from Voith differs from Windflow Technology's Torque Limiting Gearbox? It sounds very similar in its goals (deal with wind variablility early in the power chain, allowing a smaller (and/or more reliable) gearbox and smaller (and synchronous) generator) and in the choice of technology (hydraulics plus fancy gears). Despite the links above I can't find/understand enough about it to tell.

[Engineer-Poet]

Volume is the thing
My last inverter cost me
Thirty cents a watt.

(It's a Black and Decker 100 watt cigarette-lighter unit.  It came in the usual cardboard box and was probably built in runs of 100,000 or so.  Computer power supplies are built in even larger volume and are also cheaper, despite having more or less the same hardware requirements as an inverter.  When solar inverters are built in similar volume, the price will come way down.)

[Calamity]

Inverters have seen a lot of performance and durability improvements the last few decades, but prices remained fairly high.

Volume production is indeed paramount, and is likely to happen with the increasing demand of PV systems. That will lower the overall system price, which in turn will increase demand some more. A nice little positive feedback effect, which also works for most other pv system components.

Not sure if that cigarette lighter unit will last 20 years though...

[Yosef]

Maybe the same idea could be applied to solar energy: use the electricity to power a DC motor, then use a mechanical transmission like the one described here. Do I have a subject for my thesis? :-)

[Ytterbius]

"These agreements are for the delivery of a total of 1313 turbines through 2012 and represent anticipated revenue of $2.845 billion over the same period. Deliveries are scheduled to commence, 12 months of the date of acquisition, with approximately 100 committed for delivery in 2007 and a further 50 reserved."

Wow! If they pull that off, their stock will be worth a heck of alot more than two bucks a share. Yes, I own a bunch. :)

[Cleantech News]

Excellent! More and more efficient turbines...it might even be a good source of renewable energy!

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Expecting a good opportunity to work in your organisation.
If u are interested please contact me in the above mail or through [email protected].

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[Ricky]

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[George Fleming]

Even if inverters become cheap and reliable enough to compete with the Dewind concept, they greatly increase the number of electronic components in a wind turbine that can be destroyed by a lightning strike. Inverter efficiency may be acceptable at maximum power, but not over the power range that the inverter must operate in a wind turbine. The power quality of inverters will never equal that of synchronous generators. Wind farms must now be able to provide voltage ride-through and reactive power. That is easy with the Dewind concept, but it will make inverters more complicated and expensive and less reliable. I believe the Dewind concept will make inverters obsolete in utility-scale wind power.

[Electronics Philippines]

Well, I definitely agree with you there, "This proven technology has achieved MTBFs in excess of 30 years in the gas compressor industry." Well said. Wish there is also like that in our country. Anyway, I enjoyed reading this post. Thanks for sharing!

-seff-

[generic propecia]

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