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# WTG Production losses & uncertainties3

## WTG Production losses & uncertainties

(OP)
Does anybody have a spreadsheet (excel) to calculate the total loss and uncertainty for a wind turbine generator?

I have been trying to figure out how to create my own using some online references but seem to be getting nowhere with it.

Thanks guys!.
Replies continue below

### RE: WTG Production losses & uncertainties

2
Total loss and uncertainty of what?

If you mean how much actual electricity they generate in a year, its roughly equivalent to operating 12-18% of the time, say about 15% average at full nameplate capacity.

A 1 MW turbine will generate about 1200 MWh in a year.
That will cost about $1.8 million and probably generate about$150,000 worth of electricity per year at a real good wind FIT (good luck), so it would be a 12 to 15 year payback, not counting significant maintenance expenses.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying."  Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

### RE: WTG Production losses & uncertainties

Biginch, Wind turbine capacity factor is highly dependant on the available wind, hub height, terrain and turbine design and maintenance. I would be interested to know the source of your data.

Alan
"The engineer's first problem in any design situation is to discover what the problem really is." Unk.

### RE: WTG Production losses & uncertainties

OK, I might have had a low wind year.  I roughly checked last year's data at Red Eléctrica de España.  I could go to a max 22-25% of Nameplate.  Its the yearly 2009 Jan/Jan average for all wind turbines connected to the Spanish grid.

Yes you do have to be careful. Some years are lower.
Religh wind velocity distributions taken from daily maximums look nice, but don't seem to tell the whole year's story either.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying."  Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

### RE: WTG Production losses & uncertainties

No. 15-18 I think is correct.  I just now forgot to subtract parasitic losses.  Probably gets it back down to 18 or below.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying."  Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

### RE: WTG Production losses & uncertainties

Forgot to give you the link to the reports,
http://www.ree.es/sistema_electrico/boletin_mensual_ree.asp
In the monthly bulletins look down to 2.1 Balance de energia.
"Eolica" = Wind.
"Potencia" = installed capacity = 18805 MW
Año Movil = Year's Moving Average GWh = 39746
So, 39746 GWh * 1000 MW/GW / (18805 * 24h/d * 365d/y )
Gross production is 24% for April/April 2009-10
I think paracitic loads might be as much as 25%, but surely could be 15%, so that's 18-20% net.

If you're interested in the rest of the data, I think you can read the other catagories with some help, "Resto Regimen Especial" is all other renewable energy sources and "consumos en bombeos" is electricity used in pumping water to reservoirs for later use by hydro.  "Intercambios" are import/exports to Morroco and France.

Have you ever noticed how all the world's wind energy associations only publish the numbers of turbines installed, cumulative capacities installed, countries with highest installed capacities, future installation  projections, wind installed capacity as percent of total gen capacity, etc.  but never say anything about actual electricity produced.  You have to dig into the grid operator's data to try to find that info.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying."  Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

### RE: WTG Production losses & uncertainties

The company I work for is an independent power producer in the US and currently has about 1800 Mw of installed wind capacity. The actual availability range of the wind farms is from 96-98% with most of the farms running at 97% availability, on average. Capacity factors for the farms is obviously site specific but ranges 32-40%. I believe the parasitic loads mentioned above are way too high.

Regarding the financing for wind farms, they are not profitable unless there are Production Tax Credits. Otherwise, we can do a whole lot better with other sources of Power Generation.

### RE: WTG Production losses & uncertainties

Availability normally defines operating time - downtime due to maintenance.  Being capable of spinning for 97% of the time is reasonable, but spinning 97% of the time at rated capacity isn't anywhere near reasonable unless you've got them mounted on a truck.

Parasitic losses may be less than I think, but definitely more than you think.   Just choosing an economic wire size can get you as much as 5% loss right there.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying."  Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

### RE: WTG Production losses & uncertainties

I think the difference may be the average wind speeds. I don't know where this plant in Spain is located, but looking at one map, it appears only a few very small areas of Spain average > 6m/s. I'm in the U.S., where vast areas exceed 7m/s at 50m AGL. It doesn't take a big difference in average wind speed to make a large improvement in capacity factor.

In my experience, if losses are more than 5-10% of the output, there is a problem with the design or operation.

I think metengr was saying his plants average 32% to 40% capacity factor, not 97%.

Alan
"The engineer's first problem in any design situation is to discover what the problem really is." Unk.

### RE: WTG Production losses & uncertainties

(OP)
Thank you guys.
I was able to put together a spreadsheet (excel) to calculate the losses, uncertainty and come up with the standard deviation, of course, after doing some research in some of the recommended websites.

### RE: WTG Production losses & uncertainties

Sometimes it blows around here at 100 kph for a week straight min 75 kph, which actually shuts them down.  Most places where they put these things around here, don't lack for wind during the winter.  Same in the north too.  Maybe too much is the problem.  Actually during 1 day in 2007 they outlit the combined national nuclear plant production, but somehow they just don't cut the mustard for production over the year.  Suppose its the summers, which are more sunny than windy.  Here I think solar is a better fit.  Works in summer, winter, wind and no wind and at least 40% nameplate yearly production is a piece of cake. Sun with a cool wind even keeps the temps down and the production up in the winter, even though daylight is a bit shorter.

I'm not saying that in some locations you might do better, but take an average over a wide area and production is nowhere what you'd think it would be by judging from a look at one concentrated area and that's the real problem with them.  The good sites are getting used up too, which was forcing them to start looking offshore.  If that's actual metered production, after subtracting power input too, its a spactular and I think quite an unusual site.  I would imagine they are new turbines too.

There's about a thousand of them around here,
http://www.panoramio.com/map/#lt=36.155895&amp;ln=-5.691090&;z=4&k=2&a=1&tab=1

The deviation in power production would ideally match the deviation in windspeed^3, from whatever power the turbine was producing at the windspeed that the windspeed's deviation was measured from.  Assuming it was measured as standard deviation of a normal distribution of windspeed, which it might not have been, you'd expect to see almost all wind speeds within +/- 3 standard deviations from the central point.  With a Reyligh distribution, that might be somewhat skewed towards the lower end rather than across the board.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying."  Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

### RE: WTG Production losses & uncertainties

racv2,
Sorry I diverted the discussion. I don't think it's realistic to apply a single sensitivity value to the std. dev. of wind speed to get the std. dev. of production (if that's what you're doing). Can you explain how you arrived at the sensitivity numbers? You need to account for the power curve of the turbine and the wind speed distribution.

Alan
"The engineer's first problem in any design situation is to discover what the problem really is." Unk.

### RE: WTG Production losses & uncertainties

variablity of wind

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying."  Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

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