Wind Turbines

IT Minion said:
That's not how the physics works.

When there is wind they do generate, but you don't know what the wind conditions are at the location of the turbine or at 120 meters up.

Again It isn't a case of turning them off, it's that you have unrealistic expectations of how often they will be running and how often they'll be running at full tilt.
Click to expand...
People often frame idle time as a failure of wind turbines.
 
Just been to Cornwall for a week and approx 1 in 10 wind turbines were not working why ?
 
algas said:
Just been to Cornwall for a week and approx 1 in 10 wind turbines were not working why ?
Click to expand...
That means that 90% were working, That is a very high percentage.
Some people on this thread are suggesting the figure is between 15-35% working and are satisfied with that performance. I think is is ridiculous.
 
IT Minion said:
They can't in general. Some new ones can ramp down over a few hours by venting steam instead of using it, but they don't save any money by doing so. To actually ramp down or up takes them a day or so.

What turbines are you thinking of that lay idle all the time? Older, smaller ones do have much narrower operating ranges and do sit more or less still for most of the time. New big offshore ones are spinning most of the time.
Click to expand...
Some nuclear plants has been able to ramp up & down for some time, its just that it isn't worth it for most economically, so they aren't built that way.
 
Hysteresis said:
That means that 90% were working, That is a very high percentage.
Some people on this thread are suggesting the figure is between 15-35% working and are satisfied with that performance. I think is is ridiculous.
Click to expand...
Can I just remind people that wind turbines should be available to operate for at least 90% of the year, but have a capacity factor much lower. One may see a turbine going round for the majority of the time, but the capacity factor will still be much lower, as they can operate at variable outputs for lower wind speeds.

If you see some turbines dormant in windy conditions, it is usually down to grid demand (or lack of), but also errors in the turbine itself, such as oil pressure, software issue, ....(I used to have a list of the errors). Also, if its too windy, they will shutdown, and some will shutdown if there's a risk of ice, owing to risk to the public.

Also, they wait for 10-15mins of constant wind before starting, otherwise they would stop and start far more frequently, which would be bad for the bearings.
 
I believe wind turbines don’t remain completely still, they have a motor that turns them very slowly to avoid flat spots on the bearings.

They must have one mother of a bearing
 
Hysteresis said:
Hi IT, your Teesside Windfarm Statistics look correct, but I observe a recently constructed windfarm 1 mile from my home, it consists of 18 - 3MW units and is a very new construction with in the last 5 Years, and even this New installation lays idle for a lot of the time. I can't get an accurate figure for time the turbines are idle, but they are idle or partially idle during suitable Wind Windows, and it just seems madness to have units such as these idle when they dont consume energy. They should be part of the Base load production to enable Gas and Oil stations to be shut down, It may possibly be due to do with the efficiency of conventional station running at reduced power, but the fact remains, Wind Turbines should be utilised on a continuous basis to supply the base load.
It is all Madness to my SImple Mind.
Click to expand...
There is an economic question. Storage costs money.
If you had enough WT/storage capacity to have all WTs turning whenever the wind blew, it would greatly increase cost of WTs.

Baseload supply is a continuous demand, and as such, wind/solar are not suitable for this type of supply. If you wanted to use these for baseload supply, you would need many times more capacity of WTs/solar to what you actually use in the grid, and huge quantities of storage to cover those times when you have prolonged periods of dark cold still nights in winter (look at the winter of Nov/Dec 2010 for an example).

You would have such huge over capacity of the system that it would be uneconomic in the extreme. The idea that wind is currently so cheap that it will always be cheap no matter how much you have in the system is wrong, as shown in studies in decarbonising systems. It is only cheap when you have other supplies in the system such as gas/nuclear/biomass.
 
Brigadier said:
I was reading a bit about wind turbines.

Some are almost 300m tall, with a similar rotor span :eek:

Modern engineering and materials are mightily impressive.
Click to expand...
Offshore are very big, but onshore are limited in the UK to about 125m tall (last time I looked into this).
 
Hysteresis said:
That means that 90% were working, That is a very high percentage.
Some people on this thread are suggesting the figure is between 15-35% working and are satisfied with that performance. I think is is ridiculous.
Click to expand...
Because you don't understand the numbers here.

Wind turbines can be static, working or working at full power. They have a relatively wide range of speeds they can generate some power in, and a smaller range of speeds where they can generate their full (rated) power. That's just physics.

Capacity factor is the percentage of their rated power they delivered over a period of time. So a 3MW turbine that delivered 3MW for 12 hours and 0 for 12 hours would have a CF of 0.5 for that day and would have been spinning for half the time.

If it ran at full power for 6 hours and half power for another 12 it would still have a CF of 0.5 but it would have been spinning for 75% of the time.

They don't need to generate their full rated power all the time to be useful, or to generate at all hours to be useful. You don't seem to understand how they work within the market and so are demanding the wrong things from them.
 
IT Minion said:
Because you don't understand the numbers here.

Wind turbines can be static, working or working at full power. They have a relatively wide range of speeds they can generate some power in, and a smaller range of speeds where they can generate their full (rated) power. That's just physics.

Capacity factor is the percentage of their rated power they delivered over a period of time. So a 3MW turbine that delivered 3MW for 12 hours and 0 for 12 hours would have a CF of 0.5 for that day and would have been spinning for half the time.

If it ran at full power for 6 hours and half power for another 12 it would still have a CF of 0.5 but it would have been spinning for 75% of the time.

They don't need to generate their full rated power all the time to be useful, or to generate at all hours to be useful. You don't seem to understand how they work within the market and so are demanding the wrong things from them.
Click to expand...
There is not much to understand regarding the numbers. The numbers confirm that the WInd Turbines are under unitised. A capacity factor of under 0.5 is indicative of that.
If the wind blows - Use it. The original posting was asking the base question as why are wind turbine not Rotating/Generating when the WInd WIndow is open. Let the load swings be supplied by the Dirty Generators.
Simple Question which nobody has addressed in 43 pages of posting.
 
Hysteresis said:
There is not much to understand regarding the numbers. The numbers confirm that the WInd Turbines are under unitised. A capacity factor of under 0.5 is indicative of that.
If the wind blows - Use it. The original posting was asking the base question as why are wind turbine not Rotating/Generating when the WInd WIndow is open. Let the load swings be supplied by the Dirty Generators.
Simple Question which nobody has addressed in 43 pages of posting.
Click to expand...
They can't be used more, there isn't enough wind. You might think there is, but there isn't.

Nowhere in the world gets (much) more than around 30% CF out of a 3MW onshore turbine.
 
You must log in or register to reply here.
Back
Top