Bishop Hill Wind-worn
Dec 20, 2012 Energy: wind While we were all reading about climate sensitivity yesterday, the Renewable Energy Foundation published a devastating report by Gordon Hughes on depreciation of wind turbines.
The results show that after allowing for variations in wind speed and site characteristics the average load factor of wind farms declines substantially as they get older, probably due to wear and tear. By 10 years of age the contribution of an average UK wind farm to meeting electricity demand has declined by a third.
This decline in performance means that it is rarely economic to operate wind farms for more than 12 to 15 years. After this period they must be replaced with new machines, a finding that has profound consequences for investors and government alike.
The report is here.
If the lifetime of a wind turbine is 15 years rather than 25, that presumably means that the electricity it generates is going to be much, much more expensive. Douglas Carswell MP called the government's energy bill a disaster. He wasn't joking was he?
Reader Comments (51)
Electricity is a welcome by-product of wind turbines. Their main use is to make the people who advocate them, especially the green activists and politicians, feel good about themselves.
As I've said elsewhere, the current crop of turbines were rushed out, on expensive govt contracts, knowing there was a FIT to pay for their inefficiencies. Shame on them.
Why does this not come as a surprise?
Every "green" technology has been hyped with over-optimistic claims.
Typical scamster tactic.
Why are the Government too thick to notice?
Why is "trougher" Tim (Yeo) so keen to promote them?
Purpose for FIT but not vice versa. If investors are being encouraged on a wrong statement on amortisation of capital cost then blood may flow.
Might the subsidy scheme that provides a perverse incentive for turbines in the UK to be down-rated lead to a longer life for our recently installed eyesores than those that went before?
A slim silver lining to a very ominous cloud.
And do note, they say (1) offshore wind machines are even worse and (2) In Scotland [as the mad rush to build windmills continues and gets ever madder] it seems that progressively less suitable sites are being used.
Will this stop the fanatics? Will it, eck as like.
And we'll be paying for this for a long long time.
A few weeks back, someone (Philip Bratby?) posted a comment giving the capital cost of a wind turbine and the lifetime value of the electrical energy generated (at market prices). I neglected to note the figures, but there was a big difference.
The revelation here means that, presumably, the lifetime loss is even greater.
PRECISELY what I've been banging on about for some months now.
Offshore wind farms in particular are, at best, going to last twelve years (individual turbines will fail after about five years).
But - hey - I'm only a mechanical engineer - what do I know compared with politicians and green activists..?
Actual report is here http://www.ref.org.uk/attachments/article/280/ref.hughes.19.12.12.pdf
The link above is just the PR, which shows how much attention the readers are paying here...
"...probably due to wear and tear. By ten years of age the contribution of an average UK windfarm to meeting electricity demand has declined by a third"
How can this be? The aerodynamics of the blades won't have changed. Electronic bits may go wrong but they don't suffer wear and tear. Electric machines may need bits and pieces replacing (bearings and brushes - although I imagine that wind turbines don't use brushes) but don't lose efficiency with age.
What's the explanation? More down time, replacing bits that have worn out?
[Do the blades have a finite fatigue life?]
Frankly I would be surprised if an offshore windmill lasted as long as 15 years, unless there was a considerable maintenance programme...and just how many people are there prepared to climb up one of these towers to keep the bearings in working order in all weather conditions?
Martin A: I thought I had that excellent summary by Phillip Bratby in my personal notes but apparently not. Worth digging out. I may try to find it in a little while. Unless the man himself can help us again :)
@Roy, 1:01 pm: I thought their main use was to generate huge sums of cash in the form of taxpayer-funded subsidies for their manufacturers and owners?
Does anybody know what contractual obligations windfarm promotors/operators have imposed on them with regard to decommissioning? IMO there should be a "ring fenced" arrangement to ensure thqt we are not left with landscapes spoilt by end of life industrial litter.
2 Words that should bring dread to the owners and Operators of Wind Turbines "Wind Shea"
Walking out on a windy day get caught by a sudden violent change of Wind Direction .A bad Wind Shea will not only knock over people but also HGVs on Tall Bridges and Commercial Aircraft.
Acccording to Discovery Channel Air crash Investigation The least well known but surprising example of a deadly Wind Shea was the Shuttle Challenger.The perished O Ring Failure in the SRB should have sealed itself back up,But unbelievable coincidence the Shuttle at precise moment flew through a Wind Shea.Its brave crew were tragically doomed.
Most Airports have Weather Radar precisely because of Wind Shea's.Quite how a 300 foot Turbine behaves in a Wind Shea weakens the bolts that hold the Blades to the Rotor.So Worth maybe an FOI to find the Wind Tunnel test results for Wind Turbines.
Next another 2 words that should bring dread to particularly British Wind Turbine Owners and operators(and the Baltic).
Actually 3 words Salt Water Erosion.Ships at sea their engines are obviously water cooled. British Wind Turbines at sea (No Nimbys) the Generators 300 foot high are Air cooled .So the bracing Salty Sea Water Air can get in through the vents and happily eat away at the electrics.So maybe worth another FOI .
Don't forget Collisions with UFOs
splitpin: "What's the explanation [for reduced production over time]?"
Splitpin: the main problem is the bearings which are under-designed for the loads. This means that they wear rapidly and the oil leaks./ Then the gearboxes fail.
Put proper bearings in and the power output plummets. In short, they can't work economically.
The 'killer' quote is surely this:
"The normalised load factor for UK onshore wind farms declines from a peak of about 24% at age 1 to 15% at age 10 and 11% at age 15."
Easy to remember as well - '15 at 10 and 10 at 15'.
But it doesn't end there either. There's the revelation that new, larger windmills are delivering a declining capacity factore even when they're new.
Surely the politicians are going to see sense soon?
In a previous life I had to attend conferences regarding the mechanical design aspects of wind turbines, especially those in an offshore environment.
By far the majority of questions came from the “representatives” of the “money men”, backers, banks, investors etc. Their questions were always variations on the same theme “how do we keep these things working, we have far too much downtime?”
This was some 5 years ago, my involvement, was not as a design engineer. The problem was described to me as being that the demand for larger and larger turbines was pushing the limits of the materials and manufacturing tolerances?
I have no doubt that our engineering expertise and capabilities will have improved and will continue to do so but I am fearful regarding the longevity of the units presently in place. Any resolution will be very expensive and at the end of the day I know who will pay!
Don't over-egg it, though. Probably only the rotors and turbine / generator have had it at 15. Bases, masts, switchgear, distribution lines, roads, even planning permission all stay where they are.
@jamspid - I think you mean Wind SHEAR.
As a former pilot, I can testify to its effects, and even in fairly benign weather there can be "interesting" changes in wind speed, direction & temperature, particularly near the coast, when cool sea breezes can push warm air from the land upwards. I've often experienced this in the 0-500ft above ground range, which is precisely where the blades of large turbines operate...
Martin A: The Philip Bratby comment is from 4th December in response to my comment;
"Beats me why wind is expensive. There is an up-front capital cost, ongoing maintenance cost and land rental. The generator is presumably brushless so maintenance should be only required on bearings/lubricated parts. Are they all expected to suffer catastrophic failure requiring repair by total replacement after a short life? Or are the subsidies distorting the market so that too much is being offered to landowners/construction companies/other in order to cash in?"
PB;
"I once did a series of calculations looking at the capital costs of various turbines and the income they would get from the electricity produced if they were paid the wholesale price received by power stations. In none of the cases I looked at would the income over the 20 year life of the turbine be sufficient to pay back the capital cost, let alone interest on the capital, maintenance, insurance, decommissioning. Example below:
From memory, a 50kW turbine costs about £250,000. Electricity generated over lifetime = 1,750MWh. Wholesale value of electricity is about £50/MWh. Therefore lifetime income = £87,500.
They are profitable because the income they actually get from the Feed-in-Tariff is £255/MWh, ie 5 times the real value of the electricity. This gives a lifetime income of £447,000 - hence a big fat profit."
The fundamental problem with the current generation of wind turbines is that they are simply incapable of producing electricity at prices that are economically viable and competitive with other sources. Hence there is a total disincentive for manufacturers/owners to spend money improving them and eating into the profits they are making from subsidies. Get rid of the subsidies and the wind industry will disappear overnight.
Other problems are also emerging with the technology as well. In a previous life, I used to work at the DEFRA site at Weybridge. Over the past decade this has seen a vast redevelopment, and in keeping with Govt. policy all the new buildings have included green features, notably fitting turbines of the vertical rotor type on all the roofs. Subsequently it has turned out that the flicker produced by these is a serious hazard to epileptics, and virtually intolerable to everyone else - the result being that all the affected buildings (most of the site) have had to be fitted with expensive custom-made window blinds to eliminate the problem, wiping out any savings made by fitting the damn turbines in the first place.
I can't find the file where I have calcs of the costs and income of turbines, but here is roughly what I said previously.
A 50kW turbine (Endurance E-3120, a cheap American downwind turbine, beloved of cowboy developers) costs £250k to £270k to get permission and to install. If it were paid the commercial rate for the electricity, about 5p/kWh, its annual income based on a capacity factor of 20% would be about £4k. So a 25 year life income would be £100k. Hence it is uneconomic without a subsidy. The Feed-in-Tariff subsidy for a 50kW turbine is currently 25.5p/kWh, more than 5 times the value of the electricity. Hence the lifetime income with the FiT is £560k. Even allowing for annual maintenance and insurance, it is very profitable to the owner. However, if its lifetime is only 15 years then the lifetime income would be £335k and the economics is doubtful, taking account of maintenance costs, insurance and loss of interest on capital. Maintenance is usually reckoned to be about 1% of the capital cost. Many fingers could get burnt, hopefully, if performance degrades and lifetimes are short. Of course, most of the developers have no concept of any of these engineering/lifetime issues; as I said they are just cowboys who can see a quick profit. They often sell off the asset to some other unsuspecting fool and will in any case go out of business before they are faced with the decommissioning costs at end of life.
Somwhere I have the costs figures worked out for a range of turbine sizes. The most profitable scam at the moment is to put up a 500kW turbine, for which the FiT is 22p/kWh, whereas for a turbine between 500kW and 1MW, the FiT is a mere 14p/kWh.
Our best hope is that turbine performances do degrade rapidly, particularly for the offshore wind farms. These are mostly built by foreign companies and their income from the ROC scheme is totally dependent on how well they perform. So if they perform badly our electricity bills won't rise so fast and hopefully they will give up on the useless things.
Thanks so much Phillip. Indexing, indexing ... :)
One of my sons who is an engineer and has been involved on the periphery says the problems had already been identified and they are working to improve bearing life. In his words, "Just think what that poor front bearing has to do!" He says that if preventative maintenance schedules are followed, planned longevity should be achieved. It’s apparently not particularly difficult to put a new (admittedly very expensive) gearbox or generator in the nacelle. Much of the cost is in getting the whole machine fabricated and erected in the first place so they will do everything possible to keep them going thereafter. They are designed for replacement of the major parts in situ, with lifting beams and a removable floor section so you can drop the generator or gearbox if you have to. They have lifts for the maintenance personnel so no climbing hundreds of steps. He doesn't say anything about potential blade ageing problems but presumably blade replacement is also built into the design. I think what he's basically saying is that they were probably over-optimistic about longevity of components originally but the problems are surmountable. I still think the offshore ones will have significant downtime in winter. I certainly wouldn't fancy going out in a small boat in the middle of a winter gale and jumping across to the concrete base with all my heavy tools - I think the old lighthouses were isolated for months sometimes. So to summarise, it looks like total lifetime output will be even lower than we fear, and at greater cost, but it's probably not as bad as the report suggests. Unfortunately, I'm sure it won't curb Alex Salmond's zealotry.
I am not aware of what is intended when these monstrosities reach the end of their life, but I hope we have a properly environmentally conscious government at the time that will insist the owners, or if they are no longer extant, the landowners, remove and recycle them at their own cost, including removal of the foundation and returning the land to its original condition.
I have to say that instead I expect them to be left rotting in place as appears to happen in the USA until some busybody organisation complains and any clean up will then be financed by the taxpayer.
Please give generously
http://www.holgatewindmill.org/
Peter C, 4:36pm; Sorry, but I think that you will find when these monstrosities are redundant, rotting and polluting the environment (as if they aren't already), the government of the day will have absolutely no powers whatsoever to make the owners/landowners decommission the sites responsibily. As it will turn out that provisions to require them to do so were never included in the small-print when their predecessors permitted them to be erected.
https://www.youtube.com/watch?v=GApQBGgTBZE
Check out this BBC documentary about 36 minutes 30secs
There was a song Midge Ure Ultravox" Reap the Wild Wind".How big and how many you cant ever tame it.
PS Thanks Dave "Wind Shear"
Dec 20, 2012 at 2:47 PM HaroldW
Yes, thank you. I had read that but could not make sense of it.
I wasn't saying that the explanation of the falling off of output was wrong but it did not accord with my intuition and the explanation given did not resolve this.
"Erosion of the blades"? They are not operating under water with cavitation knocking holes in them.
Dec 20, 2012 at 3:00 PM AlecM
I don't see why adequately rated bearings should have greater frictional losses - I'd have thought the reverse would apply if anything.
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Something does not make sense to me here.
What's the lifetime of a 747? Thirty years? Obvioulsy it has maintenance but you don't hear that after 15 years, as 747 can only lift 15/25 = 60% of its original payload.
It's too late for existing ones but for any new ones tgere is a straightforward mechanism. The wind farm developers should be required to provide a bond against decomissioning and removal cost. This should be in place under a S106 planning agreement prior to development commencing and index linked. Developers should be required to provide records of their output fed into the grid annually. If one breaks down and isn't repaired for 12 months, evidenced by either the feed-in report or by failure to lodge one, the planning should expire and the LA calls the bond and has it demolished.
For existing ones we need to enact a law requiring the operator to enter into the above bind arrangement, or have their asset transferred to another operator who will. Harsh. But if they are serious and responsible companies they should not have a problem.
Interesting and not altogether surprising. Does anyone know what the actual lifetime/maintenance data is in Denmark, which has some of the oldest turbines? Their 20 years of production and utilization data suggests that they are already wrestling with the performance degradation problem.
Don't over-egg it, though. Probably only the rotors and turbine / generator have had it at 15. Bases, masts, switchgear, distribution lines, roads, even planning permission all stay where they are.
Dec 20, 2012 at 3:04 PM | Thon Brocket
Not so sure. There was a marine engineer who wrote at one of these well known blogs who suggested that the foundations of sea bourne turbine would be destroyed by undermining within a similar period of time. C'est à dire that they will not be economically viable at the point of turbine failure. Oh dear, all that cost again and without government, sorry taxpayers, subsidies.
If the lifetime of a wind farm really were reduced from 25 to 15 years, that would be a 40% reduction in operating hours, but only a 14-25% reduction in the NPV of the cash flow from the wind turbine, assuming a discount rate of 5-10%. However, the capital cost needed to keep these turbines operating are probably low enough (especially compared with the initial investment) to keep these turbines operating until the tower threatens to collapse. The main consideration 20 years from now is likely to be: How will the cost of wind power - after government subsidies - compare with the cost of alternatives. Investments in energy sources that don't require massive subsidies are likely to be less risky, but not necessarily less profitable.
It would be interesting - but probably impractical - to force developers to post a bond for decommissioning old turbines. If private land has been leased to a wind farm, the future of the wind farm is the sole business of the landowner (at least in the eyes of the libertarians who read this blog). If the landowner is unhappy with his current tenant (the wind farm), he can replace them with someone else when the lease is up. In many cases, the landowner becomes the owner of the improvements placed on his property by the developer after the lease is up. The landowner will be hoping that the wind farm will become a valuable improvement, not something to be decommissioned. He will prefer to receive as large a monthly payment as possible for the use of his land, not see some of his money diverted into a decommissioning fund outside of his direct control.
As for wind farms on public property, the situation is predictably worse. The government, which is subsidizing the wind farm, certainly doesn't want to increase the subsidy so that the developer can post a bond to cover decommissioning expenses. Politicians prefer to see the next generation pay decommissioning costs rather ask current customers and taxpayers to pay enough extra to cover decommissioning.
Are the customers who use electricity from Hoover Dam (or a nuclear power plant) paying into a decommissioning fund? Are they paying the cost of the environmental damage occurring downstream? If current power sources are subject to these [sensible] constraints, don't expect politicians to subject wind farms to them.
All I can say is thank goodness that people such as yourselves, who maintain this site and take the time and make the effort to refute the ridiculous assertions of the manmade climate change (or global warming, or whatever it has morphed into recently) hysterics, are with us and bringing some semblance of sanity into an insane world. I've no doubt that it will be by your collective efforts that the lunatics are returned to their supervised accommodation. Keep up the good work and Merry Christmas to you all.
Dec 20, 2012 at 4:55 PM | Salopian
I think that history is with you, from Grimes Graves onwards there has never been much in the way of post industrial clear up. It has always been the next owner who clears up the mess. If not then nature as always, given enough time, will make it all better again and hide man's endeavours (Troy and Nineveh for example). There is nothing to suggest that derelict wind follies will be any different.
SandyS;
The thing that really, really, seriously pisses me off, as a now historian of the extractive/energy industries, is that from Grimes Graves up until end of the last millenium, the UK had an almost 100% record of leading the rest of the world in these fields, but we've tossed it all away for a bunch subsidy-chasing shiessters like the Yeo, Deben and Camoron clans.
When you put everything we know together:
Wind is unreliable and may not be available when you need it most.
Our current electricity grid can not cope with large amounts of on/off energy
We do not currently have the infrastructure to get electricity from wind farms to the grid
The cost of energy from wind make industry uncompetetive and puts people in fuel poverty
65% of the worlds emitters of CO2 are not restricting their CO2 emissions
China is currently using more than half the total world production of coal
There is not one shred of empirical evidence to prove that CO2 is warming the planet
Not only are wind turbines expensive but they will not last as long as advertised
The leaked AR5 shows that the predictions of warming have so far been higher than actual by a factor of 2 to 5
We have huge reserves of cheap shale gas (and oil!)
You have to ask WTF is this government thinking?
@ Dung at 10:32 pm: "You have to ask WTF is this government thinking?"
Totally and absolutely bleeding obvious Sunshine; let's bleed these stupid and ignorant thick punters absolutely dry before they wake up and realise that we've been scamming them for the last decade with this AGW crap.
+1 Salopian...it is saddening...we saw the same thing in the 1980s when we decided that we did not not do railway enginneeering anymore. Are the Virgin trains so much more advanced than the APT?
@Frank
"If the lifetime of a wind farm really were reduced from 25 to 15 years, that would be a 40% reduction in operating hours, but only a 14-25% reduction in the NPV of the cash flow from the wind turbine, assuming a discount rate of 5-10%"
At the moment, gilts yield about 2%...so your range doubles to about 25-50 years. would that change your assumptions? Or are you one of these persons who deny mere financial facts?
Dec 20, 2012 at 5:46 PM splitpin
Something does not make sense to me here.
What's the lifetime of a 747? Thirty years? Obvioulsy it has maintenance but you don't hear that after 15 years, as 747 can only lift 15/25 = 60% of its original payload.
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Reading it, this is a statistical study of windfarms and doesn't go into the reasons for the decline in productivity.
I'd guess it isn't particularly claiming that a specific ten year old wind turbine, properly maintained will produce 0.X% of what it could produce in a wind of Y Km/H when it was new,. It's saying the windfarm as
a whole can't produce its expected new output because of unplanned downtime due to gear box failure, etc.
If I recall correctly, passenger jets have very strict scheduled maintenance, 2,000 flying hours per engine or whatever. They don't run them until they fail in service and then send someone out to have a gander, if it's not too stormy, and when they've fixed the others on their list.
The poor endurance or time between failures sounds complex from this distance. One could ask if it is more economical for an owner/operator to do the least maintenance possible, to allow the performance to degrade, even down to a trickle to maintain a feedback return, because of the 5 times multiplier. I do nor know if the feedback payback continues if the thing stops altogether then resumes automatically on the start of power after repair, and I also do not know the form of contract termination clauses at end of agreed life. One can imagine scenarios where the owner, seeing a problem developing in a machine, allows it to limp along, receiving something smaller, but not nothing.
What an unhealthy industry. It seems another case of "show me an artificial subsidy and I'll show you some corruption".
If these figures are correct then the New Zealand wind industry is in very big trouble, as there are no subsidies (as far as I can ascertain) for wind in NZ. Hence they will never make any money for the investors.
Sean Houlihane -
The Bish's link went to the Press Release, but I think many had already seen the full report from the link at GWPF.
We do read other stuff you know.
I am an engineer and I was the chairman of a wind farm action group that fought (unsuccessfully) to stop a wind farm being build close to my home.
One of the things that I did as part of the submission to the council was to try to redress the balance of the CO2 savings claimed by the developer who used a simplistic equation based on a 25 year working life. They didn't account for the carbon cost of manufacture, backup generation, turbine lifetime etc., so I redid the calculation.
One thing I managed to get my paws on from somewhere was some lifetime statistics for the Danish turbine fleet. I was shocked to discover that the life expectancy of the big turbines (i.e. 2MW, 80m ones) has been found in practice to be between just 7 and 12 years.
I ran 16 different scenarios (a number dictated by the variations in the parameters available to me). Of these 9 produced negative carbon savings and the best possible saving was around 15% of the figure claimed by the developer
Folks - do we yet have any photos/video of failed (e,g,) Danish offshore turbines..?
After this weekend (22nd/23rd December) with the predicted storm-force sou'easters, we may well have some home-grown ones..!
One can only wish....
PS - Thanks to all (Philip Bratby in particular) for putting meat on the bones of my 'gut feeling' that these things were never going to last the course...
Off-topic but relevant...
'Trougher' Yeo was on telly yesterday - interviewed on the usual subject of the government bashing the energy companies over the price of their tariffs (not ONE mention of the in-built cost of the subsidies/feed-in tariffs to 'renewables' - quel surpris)..
His immediate rant was that everyone must reduce their energy consumption. Now - forgive me for being cynical - but I read that as code for: 'Oh, sh*t - the lights are going to start going out soon because we haven't made enough provision to cover the closing of coal and nuclear power stations...'
@ Tony Leatham 12:39 pm
one US attempt to account for Life cycle emissions and life cycle cost of wind may be found here:
http://www.netl.doe.gov/energy-analyses/refshelf/PubDetails.aspx?Action=View&PubId=451