HOMER Knowledge Base

HOMER Knowledge Base

Wind turbine cut-out wind speed

The wind turbine power curve I have from the University of Minnesota shows the cut out speed at about 31 or 32 m/s.  The wind curve you sent me cuts out at 25, which makes my hydrogen and electricity way more expensive.  Is there a good reason why it cuts out earlier?

 

Way more expensive??  In your case 2a and case 2b files the wind speed exceeds 25 m/s about 0% of the time.  What makes you think the cut-out speed is having a big effect?

The product data for the V82 on the Vestas website gives three cut-out speeds.  The one-second value is 32 m/s, meaning if the wind speed exceeds 32 m/s for 1 second or more, it shuts down.  The one-minute value is 24 m/s, and the 10-minute value is 20 m/s.  HOMER uses a 1-hour time step so according to HOMER the cut-out speed should be even less than 20 m/s.  I used 25 m/s just because that's what we customarily use.

The good news is that it doesn't matter.  The hourly average wind speed almost never exceeds 20 m/s so the cut-out wind speed has virtually no effect on the system economics.  In your case, if the different power curves give significantly different results, the cause is almost certainly something other than the different cut-out speeds.  My guess is the shape of the curve between zero and 5 m/s.  This graph compares your and my power curves. You can see that below 5 m/s (where your wind is about 25% of the time) your power curve (pink) is a lot more optimistic than mine:

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