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6MW offshore wind turbine - build me 300x please

  1. Jan 3, 2013 #1
    Nice toy... :!!)

    A recent offshore wind turbine. 6MW peak power, the rotor has 120m or 154m diameter :tongue2:

    The alternator rotates at the blades' speed, without a gearbox... With D=6.5m, it uses permanent magnets, its stator must be actively cooled, and the nacelle weighs 200t.

    Still not my electrostatic alternator, but it surely is a mere matter of time.

    Some literature (zorry for ze languich):
    http://www.windpowermonthly.com/go/enews/article/1133700/ (English)
    http://www.energy.siemens.com/hq/pool/hq/power-generation/renewables/wind-power/wind%20turbines/6MW_direct_drive_offshore_wind_turbine.pdf [Broken] (English)

    Dong Energy meant this was exactly the tool they wanted, because they ordered 300 of them for 2.5G€ :biggrin:

    Let me estimate... The manufacturer alleges 23*106 kWh a year, but 44% of the peak power must be optimistic even offshore. Say 1/3 of the peak power (instead of 1/4 on land), it's still 600MW mean power for 2.5G€ acquisition cost. Thereafter, raw material is free, maintenance limited, and accidents have consequences on the turbine only.

    Compare with my favourite punch-bag, the EPR: 1600MW peak power or 1200MW mean (or zero dot nothing watt if things continue as presently) for presently 8.6G€ acquisition cost before the next increase and the penalties, plus fuel, maintenance, dismantling, 240,000 years protected storage, and disasters... well, you know.

    The wind is turning.
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Jan 3, 2013 #2


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    Nice, but you are comparing an equipment cost vs an installed cost.
  4. Jan 3, 2013 #3


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    Offshore wind maintenance is fairly expensive last I looked. As Russ points out that cost does not include installation. Nor does it include the cost of the baseload generation source to run when the wind idles.

    And possibly for those depending on the power during an outage.

    Capacity factor .75? Nuclear runs over 90% CF in the US.

    So €7.1/W installed nuclear versus €4.2/W for the Siemens turbines, equipment only.

    Maybe. Maybe not.
  5. Jan 3, 2013 #4

    jim hardy

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    Given that a state like Florida has something like 60,000 megawatts of generation
    that's ten thousand of your wind turbines assuming the wind is blowing hard enough to run them all full tilt. At more realistic 20% output it's fifty thousand of them. Just for Florida.

    So wind power is an interesting tinkertoy and talking point for politicians, in my opinion.

    Where it might make some financial sense is atop the Rocky Mountains west of Denver where the wind howls all winter long - but offshore units are too big to fit through the I-70 tunnels so you can't get the real moneymaker units up there. About the biggest thing you can get to where there's great wind is a GE 3.5mw.
    Now that's not such a bad idea - there's existing transmission lines leaving Denver crossing the divide , so it'd be plug&play .
    But it looks like the tax incentives to build them are uncertain at best.

    old jim
  6. Jan 4, 2013 #5


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    An aside: Florida built 25GWe of new natural gas electric capacity in the 2000's?

    Edit: And another ~4GWe gas fired in 2011-2012 alone. Amazing.
  7. Jan 4, 2013 #6


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    That might be a little too conservative. If Florida is like the rest of the US, then it uses only half its capacity on average. And the average capacity factor for wind is over 30% onshore, greater yet offshore. So 17,000 6MWpk towers might do on average, not that Fl would ever tolerate that onshore.

    There'd still be times when the wind dips coincided w/ the demand peaks, so there'd have to be a lot backup fossil generation (gas I suppose).
  8. Jan 4, 2013 #7


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    Why look at the power needs of Florida alone.

    Here is a link to a recent story about powering the eastern seaboard of the US with offshore wind farms:

    That's right, only 144,000 wind turbines of 5 Mw capacity and it's all FREE!
    Well, except for the initial capital expense of producing the turbines, installing them offshore, maintaining and replacing any faulty units, installing a supply grid to the mainland, etc.

    It would be cheaper to make every homeowner buy a Honda generator and run his own household.
  9. Jan 4, 2013 #8

    jim hardy

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    [STRIKE]Actually last year US is #1 in world wind capacity,[/STRIKE]
    oops - looks like China slipped past us, ( they have ~ 62 gw now) http://en.wikipedia.org/wiki/Wind_power_by_country

    but we have so much generation it's not so large a percentage of our total.
    51,630 mw of wind (51.6 gw)
    http://www.awea.org/learnabout/industry_stats/index.cfm [Broken]

    out of around 1,050,000 mw (~1050 gw, includig wind)
    Last edited by a moderator: May 6, 2017
  10. Jan 6, 2013 #9


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    "I read somewhere that..." though China has a lot of turbines, a significant fraction of the total is not connected the grid, i.e. they're "bridge to nowhere" wind turbines. Even if all Chinese wind was connected, to match actual US wind generation they'd still have to significantly overbuild the US to make up for the superb wind resource advantage the US enjoys.
  11. Jan 6, 2013 #10

    jim hardy

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    Ahh that would make sense, they could electrify small "outback" areas where there's not even a transmission system yet, without building pipelines or railroads to delive fuel.

    Our wind is largely where population is sparse. Check this map -
    Our good wind is in the middle of the country.
    Note lack of offshore wind in Florida, Georgia ..

    Last edited: Jan 6, 2013
  12. Jan 6, 2013 #11


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    Lots of good wind *resource* offshore, but so far not a single commercial turbine installed offshore in US waters. Apparently existing offshore tower designs (e.g. european waters) are not up to the stresses of Atlantic hurricanes.
  13. Jan 8, 2013 #12
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