are there any websites that tackles design flaws of wind turbines? 8

[etrobal]

we are currently reviewing bids from different wind turbine manufacturers and since we specified everything as 'bidder to specify', we have no inclination as to whether these bidder specified items are acceptable.

this is our first time to prepare specifications, bid it out, have it constructed/erected and hopefully, operate the approximately 100MWe wind farm.

of course, the websites of the WTG manufacturers are all praises for thier turbines and we wouldn't be able to dissect the bidder's specifications if we do not have any materials with which to compare, or to study.

we would appreciate if you can direct me to any web sites, papers or codes, that discusses the wind turbine specifications, from the turbine with its blades materials, gears, cooling systems, nacelle, yaw and pitch specs, brake systems, lightning arrestors, fall arrest systems, generator and other electrical systems, scada and instru systems, the tower design and the like.

thank you again, indeed, for your suggestions and advises.

 

[arunmrao]

Check their balance sheets,visit a few wind farms. A major WTG is in the midst of providing free replacement for early failure of their turbine wings/blades. A few members in eng tips have also reported gear box related issues.


If you think education is expensive, try Ignorance.
- Andy McIntyre


_____________________________________

 

[gwolf2]

I'd buy Danish, Dutch, or German, and even then do a web search and see if even they have some modern turbines with issues, preferably buy a 10 year old design with 75% of the capability of their latest offerings.

I say this not from a detailed knowledge of individual turbines but because I know what goes on in a lot of engineering design companies and the standards of stress analysis have fallen sharply over the last 10 years.

It's all about metal fatigue and the way that the life of machines scales very nonlinealy with stress levels. If you have a machine like a wind turbine which has lasted 10 years then you would be extremely unlucky for a serious fatigue issue to develop in the next 10 years. By which time it has paid for itself anyway.

(Before the fatigue specialists wade in, yes I know that at the high end of fatigue like in military gas turbines you could get fatigue problems at 4000 hours when you had none at 2000 but wind turbines should not be running that close to the edge.)

gwolf

 

[IRstuff]

You need to find a consultant, to review your proposals. It's often not just about things that are said, but also, things that are left unsaid. Only someone experienced in the field would be able to sift through the marketing stuff and determine the engineering validity.

TTFN

FAQ731-376

 

[macmet]

I second IRstuff's comments about hiring someone.

I use eng-tips and websites for a lot of issues I come across at work, but for a project with value and costs you're about to put in, it would be worthwhile to hire an expert in the field.

I would change the focus of your search to finding someone qualified to make these decisions.

 

[racookpe1978]

In addition to the above, You also need to ask for a machine-in-service history for their turbine models.

at a minimum, model number, time in service, outage history: (repair downtimes vs "no wind available" downtimes, time to start repair, time to repair, number of outages, what major items were in each outage.) Require this info for several different sites, not just cherry-picked sites that THEY picked.

Forexample - You're looking for a new car fleet, and are going to require the required maintenance expected for the first 150,000 miles. You want verification that while the oil is routinely changed every 3000 miles, the transmission and starter motor are not also changed that frequently. Alignment problems and occaisional flat tires?

Sure, every car fleet has those. But if 70% of the fleet is getting an alignment every 2000 miles, something is deadly wrong with the suspension design - even if the advertisements are going to give you "free alignments with every fillup!".

 

[metengr]

I would recommend you visit teh site below and contact DNV

http://webshop.dnv.com/global/search.asp?searchstr=wind+turbines

 

[romke]

please see this link:

http://knowledge.allianz.com/nopi_downloads/downloads/AZT_Windkraft_Sicherheit_1.pdf

the text (in german) is about their experience with wind power turbines.

the webadress list various adresses all over the world where they can be contacted.

 

[tbuelna]

etroble,

The US DOE NREL website has lots of technical resources.

http://www.nrel.gov/wind/publications.html

Current utility scale wind turbine designs have lots of failure modes. Most of these large (>1.5MW) turbines use DFI generators, which require high power inverter and rectifier circuits. When these circuits fail, the heat loads can cause nacelle fires which destroy the turbine. Due to these fire hazards, many insurance underwriters now require the nacelle housings to be made from metal instead of fiberglass.

Another common source of failure is the gearbox. The turbine manufacturers must warranty the wind turbine for something like 20 years of service. Currently, it is not uncommon for gearboxes to fail after only about 5 years of service. Which means that the manufacturer has to replace the gearbox under warranty. The wind turbine business is very cost competitive, and replacing a gearbox under warranty usually means that the manufacturer will lose money on that wind turbine.

The rotor blades are also a source of service problems. A major manufacturer of utility scale wind turbines (Clipper) has spent tens of millions of dollars replacing faulty fiberglass blades that one of their suppliers produced.

My only suggestion to you would be (as others have noted), buy a larger number of smaller turbines (ie. 1.5MW vs. 3.0MW). And make sure to select a vendor with sound financials, a proven turbine design, and a good track record on delivering what they promise.

Good luck,
Terry

 

[metengr]

etrobal;
The independent power company I work for owns and operates more than 1,000 Mw's of wind power in the US with much more to come. I would strongly suggest you contact DNV/GEC or Garrad Hassan (G-H). Both organizations have the technical resources to perform anything from a wind survey for site suitability to due diligence regarding wind turbine OEM's, and most banks prefer to see reports from either organization (3rd party Engineer) as part of project financing. As mentioned above Clipper is only one of a few OEM'S that have blade issues related to wrinkles and poor aft shear web joint design, while another turbine OEM has major structural cracking issues with a particular blade model some distance from the root.

Do not simply purchase anything until a proper due diligence is performed by a 3rd party like DNV/GEC or G-H on your behalf. These organizations also have access to operating and maintenance problems in their database of wind turbine OEM's.

 

[MachinaMan]

Hi Etrobal,

Have you tried EPRI? They should have resources but may be expensive if your employer isn't a member.

Regards,

R

 

[TVP]

I was going to mention that Germanischer Lloyd is another company that is active in wind energy, and just noticed that they have merged with Garrad Hassan:

http://www.gl-group.com/en/12805.php

 

[Sparweb]

Here's another link that you might find useful.

http://www.awea.org/standards/iec_stds.html

Steven Fahey, CET

 

[tbuelna]

metengr,

I would like to talk to you about your maintenance experiences with utility scale wind turbines. If you're interested, please e-mail me.

Thanks.
Terry
tbuelna_at_cox_dot_net