Story by Eric Worrall –
![wind_turbine_bearings[1]](https://wattsupwiththat.files.wordpress.com/2014/08/wind_turbine_bearings1.jpg?quality=83)
A few years ago, I used to know a senior wind turbine engineer. One evening, over a few beers, he told me the dirty secret of his profession:
“The problem is the bearings. If we make the bearings bigger, the bearings last longer, but making the bearings larger increases friction, which kills turbine efficiency. But we can’t keep using the current bearings – replacing them is sending us broke. What we need is a quantum leap in bearing technology – bearing materials which are at least ten times tougher than current materials.”
At the time there was very little corroborating online material available to support this intriguing comment – but evidence seems to be accumulating that bearings are a serious problem for the wind industry.
Siemens citing bearing failures as part of the reason for a substantial fall in profit;
http://www.offshorewind.biz/2014/05/07/siemens-energy-division-profit-down-54-pct/
In the announcement of the opening of a new Siemens research facility;
http://www.greenoptimistic.com/2013/03/19/siemens-wind-turbine-research/
“… The Brande test center would evaluate the main parts of their wind turbines such as main bearings …”
http://www.geartechnology.com/newsletter/0112/drives.htm (an attempt to make direct drive turbines, to reduce bearing wear)
“… More accurately, it is typically the bearings within the gearbox that fail, in turn gumming up the gearbox, but that’s a story for another time. …”
http://en.wikipedia.org/wiki/Burbo_Bank_Offshore_Wind_Farm
“… During summer 2010 Siemens decided to change the blade bearings on all 25 turbines as a pre-emptive measure after corrosion was found in blade bearings found on other sites. …”
Of course, there is the occasional video of catastrophic turbine failure;
Suggestions the industry is trying to conceal the scale of the turbine fire problem;
All of which creates an interesting question – just how much of our money is the government prepared to waste, to keep their wind dream afloat? If the costs are far greater than the industry admits, how long is the wind industry going to carry that additional hidden cost, before they try to push the costs onto taxpayers, or abandon wind technology altogether?
http://www.dailymail.co.uk/news/article-2116877/Is-future-Britains-wind-rush.html
Show off insider knowledge that the bearing problem (ref link) is perhaps one of the largest of a myriad of windmill operations problems.
Imagine yourself at a large dinner party, and a liberal (of course) makes a comment about how wonderful “green” wind turbines are.
You can chime in with, “But have they solved the bearing problem?”
With that one simple question line, you have:
1) innocently shown that you know more about windmills than the liberal ever will.
2) disarmed the person from further bolstering claims about the egregiously hideous monstrosities.
3) made everyone in the conversation happy to not have to slog thru yet another “so yesterday”, “green” energy, bullshit spiel.
4) educated everyone in earshot that the mother-earth raping, slasher, machines may not be the panacea they have been led to believe.
5) realized that given the present company, now might be a good time to leave before someone claims guns kill people.
Technical point here:
If THAT bearing shown is representative of what they are actually using, Mother of GOD, they are idiots. It is no seals ore shield whatsoever, so any grit that gets in is going to play holy hell with the bearings. No wonder they have problems.
Are they DAFT?
Forty years ago a common approach to bearings in high performance applications, such as aircraft, was to select the best out of a production lot, and sell them under a different part number. (Adding an X suffix was common.)
One selection method was often rolling them and using a vibration detector, perhaps spelled “microphone”, smoother being better of course.
Today much better manufacturing precision should be available.
(Selection was used for brightness variation in tiny light bulbs used in airliner instrument panels – AS15% was Boeing’s criteria (Aged and Selected 15%, effectively burn-in then selection), and for reliability of a tube used in airborne weather radars.
Of course if the purchaser didn’t insist on and get the selected-best items, they’d get “pot luck” from the rejects.)
PS: Of course back then aircraft components subject to wearout were life-limited – overall the machinery before it fails. I think that ships and manufacturing plants do similar, and monitoring is available (in helicopters that has been called HUMS, for Health and Usage Monitoring System). Even a pulp mill for example (makes paper) expends great effort to avoid breakdowns – the cost of time out of service of a plant worth hundreds of millions of dollars justifies preventative maintenance. Today sensors and computation are well advanced.
I suspect the wind industry is learning the hard way about maintaining costly high performance systems.
I meant “overhaul” the machinery, of course.
Disassemble, inspect, repair as necessary, replace parts like bearings, then test against specs.
Things not subject to wearout were not life limited, perhaps checked at intervals.
“penny wise – pound foolish” operators liked to do “on condition”, which for things with bearings and such I referred to as “run to failure”. One jerk maintenance manager refused to overhaul a sizeable radar antenna before the aircraft was sent halfway around the world to work for months. Sure enough, several times he incurred the cost of shipping a replacement antenna there, as it is necessary in tropical weather conditions.
If the government was not involved the investors would lose only their own money. The investigation into how the project would make money would have had a higher priority and been rejected if this problem had been highlighted.
I live near the Holtwood hydroelectric station in Pennsylvania. In 1901, they installed the first Kingsbury thrust bearing. It has worked flawlessly since. From Wikipedia : His bearing succeeded this time, and worked flawlessly for the next 25 years. When it was inspected after 25 years, there was so little evidence of wear that it was calculated that the bearing would last 1,300 to 1,700 years.[2] The same bearing is still operating smoothly today.