Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
I have only skimmed the report, but if it is wrong I don't think it is the math as such (always worth checking of course). Leaving the data, the assumptions of the model and the conclusions.

Here is some things I noted:

Data, offshore (p.22)

Evidence on the performance of Danish offshore installations is both restricted and so poor
that there may be concern that the results are affected by a small number of outliers. Still, the
sample contains a reasonable number of sites with at least 5 years of operating experience and
the decline in performance by age 5 is 38% unweighted and 26% capacity weighted.

So with more data another picture might emerge for offshore with the same analysis. I also note that on my quick read-through I haven't got a firm grasp on where exactly his data comes from.

In conclusions:

While the decline in the achieved performance of onshore wind turbines in Denmark is
much less than that for the UK or offshore, nonetheless the decline in expected output under
standardised wind conditions over 10 years is 10% unweighted and 13% capacity weighted.
These declines accelerate aſter age 10 so that the reductions in performance are 17% and 20%
respectively aſter 15 years. For UK onshore wind farms the reduction in performance due to
age is much worse at 27% unweighted and 69% capacity weighted by age 10.

Now, all machines age and I don't know expected lifetimes and such, so I don't know what one should expect. What I do find dramatic here is the difference between Denmark and UK. That does not look like a mature technology aging to me. So what is wrong with UK onshore wind?

Going through the model is kind of heavy lifting on the day before christmas, but if you need to hire in your agit-prop division you know where to reach me.

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by A swedish kind of death on Sun Dec 23rd, 2012 at 03:37:10 PM EST
[ Parent ]
Well a quick back of the envelope observation without looking at the data

Interesting that the Danish data is "restricted and poor" compared to the UK data, but the Danish data comes in a Zip file that is reported as 18Mb in size, whereas the UK data is only 3Mb now all other things being equal you'd expect the "restricted and poor " data to come out smaller than the good set, not six times the size. That thegood data is then split down into 4 seperate reporting countries only makes me more suspicious.

Any idiot can face a crisis - it's day to day living that wears you out.

by ceebs (ceebs (at) eurotrib (dot) com) on Sun Dec 23rd, 2012 at 04:44:51 PM EST
[ Parent ]
That's because the Danish set contains both on- and off-shore data. It's only the off-shore data that's called "restricted and poor."

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Sun Dec 23rd, 2012 at 11:33:55 PM EST
[ Parent ]


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