efficiency of wind turbine

[kcchow]

Hi guys,

I wonder will the wind turbine efficiency will drop after certain time we use? and how fast this efficiency will drop. I heard from some wind turbine supplier saying that the wind turbine efficiency won't drop, is it true?

[Norm]

A little more detail

[zap]

There are a few things that could cause efficiency to drop:

• Efficiency of the bearings or bearing surfaces from neglect or poor manufacturing.
• Blade performance from wear or damage.
• Magnet strength from wear (100+ years?) or damage.
• Brushes/commutator on motor or slip rings(if applicable).
• The rectifiers will have a finite life.

General maintenance should maintain the original efficiency for ___? years.

[taylorp035]

I would think it is kinda of like a car.  If you don't keep up on the maintenance, your mpg's will drop eventually.  A good look over/ tuneup should be done on a regular basis.

[TomW]

OK, I gotta say something.

I just do not understand all this worry and concern lately over turbine efficiency?

The fuel is free so unless you are losing 50% or more what is the point?

This particular question is so vague it sounds like typical FUD from an unknowing "some wind turbine supplier".

I suspect you could do some specific tests on specific machines to find the efficiency. But which efficiency? Fuel to KWH? Wind duration and speed to KWH? KWH to load versus KWH used to heat a stator and wiring?

As any machine wears it will change the dynamics of whatever it does including efficiency.

Just my personal opinion and that is my comment.

Tom

[freejuice]

Tom
Agreed!
Yep, I consider my turbine 100 % efficient....it's making power from a source I did not utilize before....some days more some days less.

OP, that's a vague question, throw some more deatils into the mix, I'm sure one of the guru's in here will help you out....I'm  the poster child  for help in this forum

[fabricator]

OK, I gotta say something.

I just do not understand all this worry and concern lately over turbine efficiency?

The fuel is free so unless you are losing 50% or more what is the point?

This particular question is so vague it sounds like typical FUD from an unknowing "some wind turbine supplier".

I suspect you could do some specific tests on specific machines to find the efficiency. But which efficiency? Fuel to KWH? Wind duration and speed to KWH? KWH to load versus KWH used to heat a stator and wiring?

As any machine wears it will change the dynamics of whatever it does including efficiency.

Just my personal opinion and that is my comment.

Tom

I have never understood this either, I'm glad I not the only one.

[fabricator]

Tom
Agreed!
Yep, I consider my turbine 100 % efficient....it's making power from a source I did not utilize before....some days more some days less.

OP, that's a vague question, throw some more deatils into the mix, I'm sure one of the guru's in here will help you out....I'm  the poster child  for help in this forum

HA! I got you beat by a mile on that one.

[kcchow]

Thanks for all the comments. Betz law concluded that no wind turbine can convert more than 16/27 (59.3%) of the kinetic energy of the wind into mechanical energy turning a rotor, then how much is the efficiency of VAWT and HAWT in this conversion efficiency; and how much is the efficiency in convertion from mechanical energy to electricity?

[ghurd]

It depends on where you start and stop.

Starting with 59.3% as the 100% of what is available, or 100% of the kinetic energy as 100%?
Include everything from transmission losses, battery efficiency, inverter efficiency, to the incandescent bulb efficiency?
That would look pretty sad on paper, but the light bulb still works.

Efficiency at cut in would look better than at 110% of rated output.
Especially if the battery was sized to be efficient, because by that time it would be dumping power.

If the performance degraded by 10%, so what.  Going from 20% to 18% should not be noticeable in a well planned and balanced system.
It would be less efficient to replace the whole thing with a new one.
G-

[Perry1]

The original posts talks about reading where a turbine was loosing performance over time. Perhaps he was referring to the Southwest units that had overheating issues and degrading magnet performance. This is a documented issue with some of their smaller turbines.
Perry

[SparWeb]

The accumulation of bug splatter on the blades is enough to affect the "efficiency".   Who will notice in the small wind scenario?  The GE and Vestas operators of the world see it differently, but they have millions of dollars on the line, too.

[aypz]

What has been the experience of this forum in wind-solar hybrids? In theory, they are a great combination owing to the complimentary nature of the two resources (wind blows most when the sun shines least and vice versa), but in practice I have not seen too many large applications of this concept…why? What are the major drawbacks?


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[farmer56]

OK, I gotta say something.

I just do not understand all this worry and concern lately over turbine efficiency?

The fuel is free so unless you are losing 50% or more what is the point?

This particular question is so vague it sounds like typical FUD from an unknowing "some wind turbine supplier".

I suspect you could do some specific tests on specific machines to find the efficiency. But which efficiency? Fuel to KWH? Wind duration and speed to KWH? KWH to load versus KWH used to heat a stator and wiring?

As any machine wears it will change the dynamics of whatever it does including efficiency.

Just my personal opinion and that is my comment.

Tom

People like free fuel. So if they got a turbine they want it to capture as much "free fuel" as possible. Hence they want 465% efficency. LOL

[DanB]

really from a practical point of veiw it's about cost per kWh.  The efficiency of the turbine is one factor in that.  So is reliability, cost of the system, time spent building and maintaining it.  The fuel is free... (coal is practically free too.. it's just dirt really ~ and lots easier to control/harness when you think about it, it's just a bit...  dirty!)

[dnix71]

Total power out does matter. If you build a unit that puts out 100 kw when it's new and the efficiency degrades 20% over the expected life of the unit, then will 80 kw be an acceptable output at the end of it's useful life?

I have quite a few HF thin film panels. The output of thin film degrades over the first three months and then stabilizes. I don't care so much about the power out brand new as I do after 3 months.

If I'm lighting a space with any type of lamp except plain incandescent then I need to know the light output curve so near the end of the lamp life there will still be enough light to do the job.  http://en.wikipedia.org/wiki/Fluorescent_lamp  At 25k hours I'm only getting half the light out that I was when the lamp was new.

If the efficiency drops by one-half over the device life then an honest cost assessment requires taking that into account. LED lighting may not have the initial efficiency of linear flourescent but over the lamp life I can come out ahead because LED's light output doesn't fade as badly.

[scoraigwind]

Most of the time it's not the efficiency of the turbine that limits the output it's the way it's sited and the wind it gets.  Wind varies enormously and a small increase in tower height can often pay better dividends than fiddling around improving the efficiency.

Where the efficiency really matters is in low winds.  That's when electricity is precious.  Luckily that's also when the current is low in the windings and the losses are minimal overall.