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Wind turbine durability

  1. Mar 19, 2012 #1

    etudiant

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    It is a puzzle to see so many of the wind turbines that are idle.
    Even in active wind farms, such as at Altamount Pass, it is usual to see at least 20% of the turbines idle. Older installations are usually idle as well.
    Why is this?
    Hydraulic turbines routinely run flawlessly for decades with very little downtime. Is it not surprising that wind turbines appear incapable of matching this?
    It does seem a huge economic burden to idle these units. These are expensive structures, stuffed with precision mechanisms.
     
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  3. Mar 20, 2012 #2

    jim hardy

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    two reasons come to mind.

    1. Wind power sells for a premium. If the utility can make it cheaper with coal than the windfarm sells it to them, that's what they will do. Unless gov't is forcing them to buy it.

    2. A single steam plant might have the electrical output of 500 to 1000 windmills.
    So you just can't afford the same level of staffing for a windmill.

    A one megawatt windmill makes electricity enough to sell for perhaps fifty or a hundred dollars an hour. It can't suppport the interest payments on loans to build it AND a big maintenance staff. If one is offline it's not a lot of revenue lost.
    Probably they wait until there's enough "Fix Me's" to justify calling out the service crew.

    Wow those ARE tiny , only 0.12 megawatts apiece. The whole windfarm amounts to half a big steam plant.
     
  4. Jul 19, 2012 #3

    mheslep

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    Altamount is one of the oldest (major) wind farms in the US. If it uses 1990's wind turbine tech it may not be illustrative of the reliability of turbines built today.
     
  5. Jul 19, 2012 #4

    etudiant

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    Absolutely true, Altamount was one of the first sites used because it is also one of the best sites available. So it will have old turbines, but that still leaves the question of why so many of them are not replaced, but left idle when the wind continues to blow . I'd have thought that there would be a push to use the resource, not to waste it.
    Yet that phenomenon, lots of idle turbines, is apparent wherever wind farms are found.
    I've seen it in several places in Europe as well.
    Can anyone from industry help explain what is going on?
     
  6. Jul 20, 2012 #5

    AlephZero

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    Companies don't build wind farms to make electricity. They build them to make money.

    If you get a huge governmemt subsidy for building a new wind farm, and peanuts from the electricty it generates, it's not your problem that the system is "stupid". You just build it and take the money.
     
  7. Jul 20, 2012 #6

    jim hardy

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    the resource is tax credits.
    It's largely foreign banks financing US windfarms and transmission lines, as well as lots of other infrastructure. It draws foreign money into US which i guess makes government happy.

    Put on your accountant's hat - when the balance sheet no longer justifies running the darn thing because there's no production tax writeoff, you abandon it.
    This page says the tax credit generally goes ten years
    http://dsireusa.org/incentives/incentive.cfm?Incentive_Code=US13F [Broken]

    An older Nuke plant that's no longer paying interest on the loan to build it can make electricity for about what the windpower production tax credit amounts to.
    A utility that's run by accountants might do better buying an old Nuke than a windfarm.
    That's why gov't is mandating certain % electric generation be renewables, it creates a market for them.

    You need to read C Northcote Parkinson's 'Law of Delay' to become properly cynical about the oxymoron '(insert corporate or government) wisdom'.
     
    Last edited by a moderator: May 6, 2017
  8. Jul 20, 2012 #7

    jim hardy

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    Please dont take me for anti- green.

    What we as good citizens should do is reduce our use where we can.

    A flat plate solar water heater will work in most of the US and heating water is a big chunk of your electric bill.

    Somebody neeeds to make a solar airconditioner for the sunbelt, perhaps a sealed ammonia or steam system that runs in batch mode sized for the 12 hours of sunlight.
     
  9. Jul 20, 2012 #8

    mheslep

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    In the US the two, wind power generation and the subsidy are connected, hence the name "Production Tax Credit". The operator is given a subsidy per kWh generated. No power, no subsidy.
     
  10. Jul 20, 2012 #9

    mheslep

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    Do you have a source handy for that claim on "largely" "foreign" finance or wind turbines?

    Sure, though the relevant question with wind turbines or any other enterprise is what's on the balance sheet. Is it the case that these old 1990's turbines break as fast as they can be fixed, or is any maintenance on any tower (new or old) cost prohibitive?

    Even with zero PTC the wholesale price of electricity in California is 3-4 cents/kWh, and these wind turbines don't need a large staff of well paid security guards and operators, nor refueling every three years. So the question is can a wind turbine be maintained annually when it makes 3-4 cents/kWh at 30% capacity factor.
     
    Last edited by a moderator: May 6, 2017
  11. Jul 20, 2012 #10

    mheslep

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    Another relevant point: the US spills (ie throws away) 1-3% of its total wind generation because the operators occasionally find themselves in a situation where they have surplus power, but the load point and predictability are such that they can not gamble on idling a fossil plant to use the wind generation and then have the wind die. I have no idea if this explains the observation of many idle wind turbines reported above. It would not surprise me to find that, when operators are forced to idle turbines during a surplus, they concentrate the shut downs in areas of high maintenance cost, i.e. the oldest turbines.

    Wind Curtailments.
    The above suggesting that some wind farms are built knowing that on day one of operation there is insufficient transmission to deliver peak output of the wind farm should it occur.
     
    Last edited: Jul 20, 2012
  12. Jul 20, 2012 #11

    jim hardy

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    not all in one place.
    The way i got into it was this

    a friend is developing a windfarm and has courted several investors.
    When i tracked them they were all backed by European banks, largely Spanish , some Italian one French.
    Tracking the other investments on the bank's sites i found they are building toll roads, transmission lines, dams here...

    One almost has to go company by company.
    You'll notice GE is the only US manufacturer of wind turbines.
    Look at Vestas, Nordex, Alstrom, Siemens, and see who's financing the farms using their turbines.


    http://www.renewableenergyworld.com/rea/news/article/2012/05/foreign-dominance-of-us-clean-energy-market-spells-trouble-for-america [Broken]

    http://www.sustainablebusinessoregon.com/articles/2010/09/iberdrola_plans_6b_investment_by_2013.html
    http://issuu.com/thirdway/docs/third_way_report_-_fire_sale_the_end_of_american_o/1#download [Broken]
    this is all i could get, it's behind a subscribe-wall..
    http://www.dallasnews.com/news/washington/20091117-Dallas-investor-Chinese-partners-propose-1032.ece
    then try to figure out just who owns whom..

    http://www.terra-genpower.com/News/Allco-Finance-Group-(AFG)-Announces-the-Sale-of-th.aspx [Broken]

    Allco seems to be Australian.
    Terragen i'm not sure, but they seem entwined with these guys:
    http://global-infra.com/ , click on their investments..
    http://www.terra-genpower.com/Home.aspx [Broken]

    i think we've achieved globalization.

    I'm glad i'm a theta.

    old jim
     
    Last edited by a moderator: May 6, 2017
  13. Jul 20, 2012 #12

    AlephZero

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    Well, let's not go off topic to the question "if wind power is economically viable, why does the wind industry even need subsidiies"...

    But back to the OP's question, another issue is distributing the power form the wind farm to the consumers. That had led to silly situations in Scotlamd for eaxmple, which has good sites for onshore wind farms but low local demands for power. That has led to wind farms being built (and subsidised) that can not be run at full power because the distribution network doesn't have enough capcaity to handle the power being generated, and the distribution companes (which are separate from the generation companies, and don't have the same access to "green energy" subsidies) can't afford to fix the problem using their own finances.
     
  14. Jul 20, 2012 #13

    mheslep

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    Yes insufficient transmission is a plausible explanation for the reports of idle wind turbines, though I have no specifics from operators showing this to be the case. Doesn't address whether or not the wind farm is economic; it may still be.
     
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