NREL tests small wind turbines for certification
January 6, 2010 by admin
Filed under Featured Small Wind and Community Wind Articles, Wind Power Products
To help the wind industry offer consumers more small wind turbine systems that are certified for safety and performance, the National Renewable Energy Laboratory (or NREL) and the U.S. Department of Energy (or DOE) launched a Small Wind Independent Testing project in 2007. The small wind turbines were tested to standards adopted by the International Electrotechnical Commission (IEC) and in compliance with the draft American Wind Energy Association (AWEA) standards for small wind turbine systems.
The resultant test data may be used by the Small Wind Certification Council, a nonprofit organization formed with support from the Department of Energy, American Wind Energy Association, state energy offices, and wind turbine manufacturers to certify small wind turbine systems. Small wind Certification Council certification is commenced during 2009. Test data might also be submitted to international certification agents as partial input for international certification. Small wind turbines that are tested and certified will give consumers greater confidence that the wind systems they install will perform within specified wind regimes as advertised by the manufacturer.
Through a competitive solicitation, NREL selected four commercially available small wind turbine systems to test in 2008/2009 at its National Wind Technology Center near Boulder, Colorado.
One of the small wind turbines selected for testing was Mariah Power’s Windspire Giromill. The Windspire is a 1.2-kW vertical-axis wind turbine. The turbine tower is 9.1 meters tall, and its rotor area is 1.2 x 6.1 meters. The turbine has a permanent-magnet generator with a single-phase output at 120 volts AC.
Another small wind turbine selected was Gaia-Wind’s 11 kW wind turbine. Gaia-Wind’s turbine is a three-phase induction generator that operates at 480 volts. The turbine’s downwind rotor has a 13-meter diameter, and its tower is 18 meters tall. The two-bladed, oversized rotor is designed for low to moderate wind speeds.
A third selection for NREL’s testing of small wind turbines was the Entegrity Wind System’s EW50, the largest of the turbines tested. The EW50 is a 50-kW, three-bladed, horizontal-axis downwind small wind turbine. The turbine’s rotor diameter is 15 meters, and its hub height is 30.5 meters. It has a three-phase induction generator that operates at 480 volts AC.
The fourth small wind turbine that was tested in the original round of testing was the Abundant Renewable Energy’s ARE 442. The ARE 442 is a 10-kW, three-bladed, horizontal-axis upwind small wind turbine. It has a hub height of 30.9 meters and a rotor diameter of 7.2 meters. The turbine has a single-phase permanent-magnet generator that operates at variable voltages up to 410 volts AC.
To read more about the results visit the NREL small wind turbine independent testing website.
NREL’s only tested four manufacturers over the past two+ years. Truly a surprise there have not been more, especially because of some recent performance issues revealed in the Warwick Wind Trials (WWT) in the early part of 2009. http://www.warwickwindtrials.org.uk/8.html
Small wind turbine (WT) sage, Mick Sagrillo even raises the WWT in one of his posts –
http://www.awea.org/smallwind/sagrillo/warwick_urban_wind_trial_project.html
There are approximately 408 small WTs on the market (340 HAWT, 68 VAWT) from 159 WT manufacturers, as of today– http://www.allsmallwindturbines.com/ .
In the summer of last year, Boston-Cambridge Museum of Science installed some WTs: Architectural Wind AVX1000, Swift, Proven Omni Roof, Southwest Windpower Skystream 3.7, Mariah. There was an ANSYS CFX/Fluent CFD software webinar a few months ago on this installation/test environment — http://www.ansys.com/demoroom/swf/demos/114_Wind_Energy_Projects/index.html – You might have to register to view. You can use the slider bar to advance the slide show. At ~25:00 you can see all the WTs.
An interesting aside: Using ANSYS CFX, they were able to optimize the location of the Swift WT.
This all being said, I think it would help the small wind industry a great deal of more manufacturers had an independent review of their machines. The results from the 2007-2008 12-month Warwick Wind Trials in the UK reported discouraging wind energy yields for the 26 small, building-mounted wind turbines. In this trial, wind turbines sited in a veritable plethora of urban canopies were compared to rural areas that possess low surface roughness/texture. Small wind turbine manufacturers capacity claims fell far short of the results returned in this trial compared to their claims included in specification sheets. I can attest. I have seen and analyzed the data from the WWT, and most of it ain’t pretty.
Since certification is quite expensive, such test is the only possibility to get for customer performance report on small wind turbine. I beleive this type of testing cshould be also integrated with other countries to avois duplicating testing, the important would be to have an international standard to have most the small wind turbine test. The selction of the wind turbine to be tested also is a important parameter for customer, since bad design and porr quality should be avoided at first.
I like the way you think Daniel. Collaborations to arrive at an international standard would be prudent.
There was also a trial that ran for a year in Schoondijke, Zeeuwind of The Netherlands lead by Sander Mertens at Ingreenious.com.
http://nos.nl/artikel/85544-kleine-windmolens-leveren-weinig-op.html – Ik spreek maar een beetj Nederlands (I only speak a little Dutch). Ja, it’s in Dutch, so you’ll need to use a translator to get a contextual overview. Outcome was similar to the Warwick Wind Trials on the performance results.
There already is an International Standard for SWT. Look up IEC 61400.
In the UK check out MCS . Not only do manufacturers need to be accredited by a Certified Body but also Installers.
There’s a French organisation called SEPEN (Site Expérimental pour le Petit Eolien de Narbonne)testing small wind turbines up to 10kw – http://www.sepen-montplaisir.fr -
They publish the reports after the tests if the manufacturer agrees. Worth comparing turbines.