Wind Turbines: The 30% Capacity Factor Myth

I don't know about you, but I am getting really tired of large corporate bodies continually peddling half-truths and even outright lies in order to service their own greed.

Take the wind industry for example. Especially with the way they try to big up the ludicrous ineffectiveness of their money machines.

Truly, if it was not for the fact that they get paid (at least) twice for their intermittent and unreliable production of electricity, these ugly white elephants would be abandoned and left to rot.

Whenever the wind industry talks about the capacity factor (that's the actual averaged output over a year compared to the maximum turbine rating) the wind industry always try and pretend that this capacity factor is 30%.

While this may sound low, it is actually a massive exaggeration on the real figures.

Unfortunately, the wind industry have repeated the lie so many times it is often taken as" a given" by organisations that should know better.

So what is the capacity factor for on-shore wind turbines?

Luckily there are people like Professor Michael Jefferson who has has done an analysis of the exaggerated claims of the wind industry.

His presentation is available Here

While his presentation truly demolishes the mythical 30%, it is just one of the many false claims he debunks. His presentation is well worth a read.

Look at this for 2009: (taken from Professor Jeffersons presentation)

In 2009, the real capacity factor for on-shore turbines was 21% NOT 30% Only 7.5% achieved the mythical 30% capacity factor. In other words 92.5% of on-shore turbines in 2009 failed to reach the 30% capacity factor that is promoted by the wind industry. Remember, since 2009, it has got even less windy.

Even in 2008, which was an abnormally windy year,  over 81% of on-shore turbines failed to chalk up a  30% capacity factor. In fact in 2008, the windiest year in recent history, the real on-shore average capacity factor was 23%.

So when is the wind industry going to stop telling lies?
When are they going to confess that the real output from these monstrous money making machines is much less then the figures they ritually push?

If you are waiting for the truth from the wind industry, I wouldn't hold your breath.

But even this farcically low capacity factor hides the true hideously ineffectiveness of these white elephants.

Always remember when comparing capacity factors of generating equipment that wind power is intermittent. With wind, most of the energy arrives in infrequent, irregular and unpredictable bursts. Most of the time their actual output is much less than even the real dismally low capacity factor.

But more on this in a future post.


Anonymous said...

I don't know about you, but I am getting really tired of bloggers continually peddling half-truths and even outright lies in order to service their own ego.

Notice the ommision of the percentage of wind farms achieving between 25-30%.
And no mention if the figures are including domestic or small scale turbines which are expected to have lower capacity figures.

Anyway, what does it matter? Every MW generated by a wind farm is a MW that a fossil fueled power station doesn't have to produce.

Lets have more wind farms!

BilloTheWisp said...

Dear Anonymous,
Please look at the table. A little maths is required.
Achieving UNDER 25% is 70.5%
Achieving OVER 30% is 7.6%
Now (not even having to take my socks off) I can calculate that the percentage achieving 25-30% is....
100 - 70.5 - 7.6 = 21.9% - pitiful
That is when BWEA is telling us all it is around 30% much more for offshore...(ROFL)

Prof Jefferson's table refers to Wind Energy Developments. OK it does not say specifically large scale but he is talking ROCs not FITs. See his presentation on the link.

If you need further proof about how dismal the CF really is have a look in this latest DECC document about how bad it was in 2010 (worse than Jeffersons 2009 report)

Last year even off-shore failed to break the mythical 30% CF. England On-shore was a joke 21%

What does it matter? Live in the real world. Using Wind Turbines to save carbon is like trying to bale out a dinghy with silver spoons. It is ineffective squanders resources and is ridiculously expensive. It achieves next to nothing - except lining the pockets of those selling the silver spoons.

As for having more wind farms, I suppose if you are a rich landowner or a large multinational (Infinergy - read Koop PLC, RES - read McAlpine PLC) all living off the backs of the poor then maybe more wind farms is a good idea. For the rest of us it would be a disaster.

Anonymous said...

Why would it be a disaster?

I think you are forgetting, there are no government subsidies for wind farms.

They only get paid for the energy they produce.
Therefore if they produce so little energy as you say, then they wont be making the vast profits you claim.

Come on Billo, I guess it's a bit embarrasing to be shown up on your own blog but surely you can do better than unreasoned rants!

BilloTheWisp said...

No government subsidies?

Oh come on - are you having a laugh?

Have you never heard of the ROC? True the government does not pay - it the the poor bloody sods who have to soak it up in their electricity bills.

An on-shore windfarm gets paid (at least) twice. Once for the electricity and once for the ROC certificate. It does not have to guarantee any form of generation and can, on the rare occasions they actually generate significant amount of power, they can dump energy onto the grid whether it is needed or not.

As has been the case in these rare high generation scenarios, especially at times of low demand the wind companys can and do hold the Grid to ransom. In one case one of these greedy bastards got paid 800 MW/Hr just to put the breaks on at 3 in the morning. Needless to say, the next day when power really was needed the things were becalmed.

Without the ROC there is hardly a wind turbine in the country that would be viable.

Have a look at my post The Great ROC RipOff in the wind turbine section. Even better look at Pref Jeffersons presentation available via a link on this post.

See the real economics of this scam - do not just get swept along with the fashion.


James said...

Something is very wrong with your figures.

Take a look at DECC Dukes report 2011 (
Table 7.4 on page 214.

Onshore load factors:
2008 = 27%
2009 = 27.4%
2010 = 21.7%

2010 was a particularly calm year, in the first half of 2011 onshore wind was up 64% on the corresponding period of 2010.

For Sept.2011 over 10% of UK electricity was generated by wind.

BilloTheWisp said...

Oh Thank God!

Somebody who is not only willing to challenge the maths but quotes a verifiable reference to back it up.

While I think you have made a fundamental error regarding these figures, at least I can see the validity of your challenge.

Your figures for these 3 years for the UK are correct.

But you assumption that there is something very wrong with Prof. Jeffersons figures (i.e. mine by usage) is incorrect.

The first and most important aspect of Prof. Jefferson's figures is that they relate to England only - NOT the UK (i.e. exclude Northern Ireland, Scotland and Wales)

However this is not just a pedantic get-out, because actually the 30% CF is also myth for the whole of the UK on-shore fleet. It is just even worse for England than the rest of the UK.

See below.

The most succinct representation of this data on a region by region basis is in another DECC document here...

See table 6 page 25.

While this document only gives regional figures for 2010 it does extend your UK load factor figures back for ten years. The document, needless to say, uses DUKES as its base.

See Chart 13 page 26

Clearly for England the 30% CF myth is a myth of Brothers Grimm proportions.

But even for the whole of the UK on-shore turbine fleet it is still a myth.

Look at chart 13. At no point in that ten year period did the UK on-shore load factor ever reach 30%.

So I think it reasonable to state that the 30% CF is a myth.

The closest it came was circa 28% in 2008 which was not only the windiest year in this 10 year sample but also (if my memory serves me correctly) the windiest year on record.

Last year, even the much bigged up Off-shore did not reach 30% - how dismal is that.

OK the trough of 21% CF on-shore UK wide in 2010 was only one year. But so was the peak of 28% in 2008 only one year.

I repeat: At no time in the last ten years has the UK CF ever reached 30% for on-shore turbines.

The average of the CF over the last 10 years has been 26-27% that is a full 10% (27/30) below the figure wheeled out every time somebody wants to promote on-shore wind-turbines.

But look at the catastrophic annual CF variation.

Forget about half-hourly intermittency. Look at the annual variation.

From peak (2008) to trough (2010) that gives an annual output variability of 25% to 33% depending on whether you look up the tree or down it.

Now think of the logistics of organising the plant backup - just to cope with this annual variation, An annual on-demand backup that may happen or may not.

Are to going to fire up your backup? Needlessly ready to roll - just in case.

Or possibly get caught short if we ever have another 2008.

Then add on the short term intermittency.

This is big engineering. You cannot just turn it on or off like a light switch.

While the 30% CF is a clear myth there are many more even worse half-truths and lies being peddled by the wind lobby. More about those in future posts.

But thank-you for the coherent challenge. I can and do make mistakes.

But not this time.

BilloTheWisp said...

In the last comment from me (reply to James...)

"Or possibly get caught short if we ever have another 2008."

should read

"Or possibly get caught short if we ever have another 2010."

Anonymous said...

You still haven't explained why it would be a disaster.

As you know, ROC's are only paid for electricity generated. No power - no money.

And it's still far, far less than the £billions the tax payer is having to fork out to decommission the old nuclear plants.

And yes, conventional power stations get public subsidies too.
So let's get some perspective here. Without ROC's, wind farms wouldn't get built. Without wind farms we wont be able to de-carbonise our power supply. If we don't de-carbonise the power supply we should hold up our hands and say, "yes we screwed up the planets climate and condemned the majority of life to extinction because we just didn't care enough."

BilloTheWisp said...

Dear Anonymous.
It will be a disaster the bog standard average people off this country who actually have to pay for these hopelessly ineffective things.

Every time the price of electricity generation goes up by 1% another 40,000 households are forced into fuel poverty.

Already wind has added £70.00 to the average fuel bill (by ROCs) and that is for an incredibly low per centage penetration of the electricity market.

Wind gets paid twice - de facto. It is allowed to produce whenever it can, does not get penalised when it fails to generate and on the rare occasions it produces more than the grid needs, it is allowed to hold the grid to ransom in order to shut down.

It is not only a hopelessly ineffective and costly method of generating electricity it is also a hopelessly ineffective method of cutting carbon emmissions.

Nuclear and Hydro are the only large scale viable carbon free electricity generation technologies. You can also use gas to cut carbon from equivalent coal plant by 60% - and at a generation price that is the lowest on the market.

Your statement about decomissioning is bogus. Firstly you ignore the decommissioning cost for the thousands of wind turbines - which is foolish.

See this post )

- it has a link to a very thorough and authoritative document concerning the actual costs of electricity including decommisioning cost and projected fuel cost hikes. In it you will find (as the French already find) that nuclear is cheap, reliable and effective method of generating carbon free electricity.

"And condemned the majority of life to extinction because we didn't care enough"
[end quote]

Indulging in inaccurate and ludicrous statements merely shows up that you simply do not understand the problems associated with global warming and power generation.

Using Wind turbines as a method of generating carbon free electricity is about as useless as trying to bale out a sinking dinghy with a silver spoon. Yes, you will shift a ridiculouly small amount of water, but the cost of that silver spoon could have been used to buy a much more effective baler.

You need to take off your rose tinted glasses and stop indulging in wishful thinking.

Do the maths.

Anonymous said...

Sorry, you are simply wrong, on so many points.

If wind produces more than required, it does not hold the grid to ransom. Have you never heard of exporting via the cross-channel HVDC link or simply turning off fossil fuel plant?

According to the DECC, hydro only supplies about 1.3% of our electricity and "Opportunities to use this technology on a large scale are now limited".
So not large scale really.

Nuclear decommissioning is now estimated at well over the £73 BILLION the National Audit Office reported in 2008 (ref.
Which the tax payer has to pay, unlike wind turbines that will be taken down by the operators, indeed the comparison is laughable.

We simply do not have the money for nuclear, there are only two plants being built in Europe at the moment, both are considerably over budget, over schedule and plagued by safety issues.

So now lets look at your claim that wind has added £70 to the average electricity bill.
Yet another twisted attempt to discredit wind, yet another myth in the making, yet another expression of your irrational hatred of wind turbines.

Onshore Wind was actually responsible for no more than £6 on the average household electricity bill during 2010.

Ofgem’s Renewable Obligation report for the 2009-2010 period shows that about 34% of the scheme’s funding went to onshore wind. The Department of Energy and Climate Change have issued a report (November 2011) which gives a breakdown of the amount spent on the Renewable Obligation from an average combined (gas and electric) household energy bill of £1260. The figure given is £17.

Combining the two sets of information shows that onshore wind contributed about £5.78.

Reports such as the Pöyrys 'Closing the Energy Gap' (ref.
Or the SRU German Advisory Councils 'Pathways to a 100% Renewable Electricty System', show that we can de-carbonise the supply.
We have to reduce our electricity demand, set aside our gas reserves for space heating and increase all our renewable power options, (of which wind is just one but the most effective).

Given the analogy of sitting in a sinking dinghy, I would rather be bailing with a spoon than sitting there doing nothing.

BilloTheWisp said...

Dear Anonymous,

UK Hydro resources are severely limited. If we are going to cut carbon emissions, we must use nuclear. There is no other viable option. This also means that we cannot use hydro as a significant storage medium.

We could also significantly reduce carbon emissions by replacing coal with gas, especially if the reported gas reserve under Lancashire is correct.

As for holding the grid to ransom - Denying the facts of the situation is really not going to get anyone anywhere. Read my post The April Wind farm Robbery and the associated references.

The Anglo-French interconnector rarely gets used other than unidirectionally - providing the UK with French nuclear generated electricity of around 1-2% of supply.

We use the French nuclear generated electricity for several reasons, one is when wind fails to deliver.

Ironically when wind does actually manage to produce some power it is usually the interconnector (with French carbon free nuclear power) that gets reduced first.

To be able to potentially export electricity, especially from widely dispersed wind turbines you need to squander resources building a massive amount of infrastructure that will only ever get used very occasionally, if at all.

More resources wasted on a fashion statement.

"simply turning off a fossil powered plant"

Sorry Anonymous. You cannot simply throw a switch.

The cold hard facts are that for every MW/hr that normally costs £50, onshore wind gets paid £50 for the electricity and ANOTHER £50 for the ROC. Offshore gets TWO ROCs so they get £150 in total. Wholesale on-shore wind is 200% the price of normal generation. Off-shore is 300%.

No ifs, buts, or wherefores. That is the madhouse economics of this scam.

If we ever managed to produce 20% electricity from wind with a 50/50 split between on-shore and off-shore that would mean that this 20% would account for 50% of the wholesale cost. AND that does not include the back up, extra infrastructure or decomissioning.

"unlike wind turbines that will be taken down by their operators"
Just like in the Mojave desert perhaps? Or perhaps like the ghosts on Hawawii?

As these things get older they will get more unreliable - like any rotating machinery operating in a hostile environment. Then they will be sold on - and on.

Finally, they will be owned by a company operating out of a post box in Belise. Then, after they have lain derelict for several years the tax payers will pay to have them scrapped.

If I was in a sinking dinghy I would not waste my time baling with a spoon - I would look for a more effective method of saving the situation.

Baling with spoons, like the whole wind power scam is like re-arranging the deckchairs on the Titanic.

Actually doing nothing IS better than futile activity. Futile activity simply wastes what resources you do have and leads to complacency.

But we DO have viable methods to generate carbon free power and generate power with a massively smaller carbon footprint. Nuclear and Gas respectively.

Do I hate wind turbines? Come on - get a grip.

A wind turbine is a machine nothing more or less. If it was an effective method of generating electricity and reducing pollution I would be a supporter.

But they are not. They are hopeless.

I will read your references which I am very pleased to see. This is a step forward - an attempt to back up your position rather than simply denying the facts and issuing pro-wind propaganda parrot fashion.

Unfortunately I am somewhat challenged for a good internet connection at the moment but I will download them asap.

In my posts, I hope to challenge the wind turbine scam by using reliable and accurate data, prepared by scientific and economic leaders in their field. Like the Prof. Jefferson's Powerpoint presentation in this post.

In fact the basis of this post seems to have got lost in your tirades.

The 30% Capacity factor Myth IS a myth.

Look at the figures.