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Offshore wind farm construction - more pictures

by Jerome a Paris Fri Feb 26th, 2010 at 05:51:55 PM EST

After showing you pictures of offshore wind turbine foundations in this story, I am pleased to be able to now post pictures of the above-the-water parts, before their installation at sea:


Left: nacelles with the hubs being installed
Right: blades (45m long) stacked

Part of the Wind power series. More below:


If you remember, there were ovality issues with one foundation last time round - well, that was solved and that foundation has now been corrected and installed at sea. The foundation site has just one big item remaining:


the transition piece for the offshore high voltage transformer station

This transition piece is heavier than the others, and required a re-fit of the jackup barge to be installed. That refit was being done when we visited:


Left: two of the legs that go down in water to lift the platform above the water when it needs to work
Right: the jackup is in the "raised" position in order for the re-fit work to be done in perfectly stable conditions, even in the port

After installing the foundation for the transformer, the vessel will be refitted a second time to begin in a few weeks' time the installation of the towers and turbines, which are arriving at a nearby site:

the nacelles (Vestas V90 - 3MW)

the hubs

the blades

the first part of the tower

The installation method chosen for this project is to install the turbines with the hub (but not the blades) on top of the towers (which are brought in two parts and are assembled on site) onshore, and transport the full unit to the site at sea in one piece, in a vertical position. Thus, other than the installation of that unit on top of the foundations, the only work offshore will be the installation of the blades, one by one, on the hub.

On the port site, various bits of assembly are happening now: the towers are being erected:


The fully erected towers stand at above 100 meters

The hubs are being attached to the nacelles:


The hubs are first positioned alongside the nacelles


after having being raised into position (something I did not witness), the hubs are bolted to the nacelle


a complete nacelle + hub set in front, with one to be installed behind it

I hope to be able to post more installments in the future - but joining the installation work at sea is usually more difficult as the safety requirements are absolutely stringent and the boats can be mobilised for more than a few days... to be continued.

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working on the port site on any given day.

Of course, there's quite a bit more work in the manufacturing process, and even the overall project management itself occupied almost as many people...

In the long run, we're all dead. John Maynard Keynes

by Jerome a Paris (etg@eurotrib.com) on Fri Feb 26th, 2010 at 05:54:32 PM EST
I have no words for how cool this is, nor for how much I wish I had a job like yours.
by PIGL (stevec@boreal.gmail@com) on Fri Feb 26th, 2010 at 08:29:00 PM EST
[ Parent ]
amen, i get the same kick from this as NASA freaks get from the space station!

proud of J, and Europe too.

i always felt we would have much better luck with space exploration if we sorted our situation down on Gaia first. to see the remaining fossil fuels channeled into sustainable energy is a cherished dream, and one of the main reasons i came to ET.

the engineering involved (including financial!) staggers the mind.

brilliant!

'The history of public debt is full of irony. It rarely follows our ideas of order and justice.' Thomas Piketty

by melo (melometa4(at)gmail.com) on Sat Feb 27th, 2010 at 04:27:16 AM EST
[ Parent ]
Jerome, any chance of higher resolution versions of these on flickr or somewhere? And I'd love to use them in presentations, with your permission.
by LondonAnalytics (Andrew Smith) on Sun Feb 28th, 2010 at 03:33:28 AM EST
[ Parent ]
sorry, these are iPhone pictures...

In the long run, we're all dead. John Maynard Keynes
by Jerome a Paris (etg@eurotrib.com) on Sun Feb 28th, 2010 at 03:44:14 AM EST
[ Parent ]
but feel free to use as long as you link to this story.

In the long run, we're all dead. John Maynard Keynes
by Jerome a Paris (etg@eurotrib.com) on Sun Feb 28th, 2010 at 03:45:28 AM EST
[ Parent ]
Thank you. Shall do.
by LondonAnalytics (Andrew Smith) on Sun Feb 28th, 2010 at 07:46:48 AM EST
[ Parent ]
What is the estimated lifetime of a wind turbine?
by asdf on Sat Feb 27th, 2010 at 02:03:36 PM EST
For both design and financial calculations, 20 years.  Historical evidence shows that including parts changeouts, we're already past 25 years.  Lifetime depends on good original siting (less turbulence), and quality control of both manufacturer and operator.

PS.  J's project is also the first (offshore, to my knowledge) to use carbon fiber in the blades, decreasing weight and increasing stiffness, enhancing projected lifetime.

"Life shrinks or expands in proportion to one's courage." - Anas Nin

by Crazy Horse on Sat Feb 27th, 2010 at 02:24:56 PM EST
[ Parent ]
Since this is offshore I've got a question.

One of the costs of going offshore is the foundation work.  Setting a foundation in water (even shallow) water involves a lot of expense.  

Can the foundation be reused, so that you could have a new turbine on the same site without reworking the foundation.  

How about the towers?

It seems like the stuff that would have a limited life span would be in the nacelle.  Can you switch out nacelles to cut costs on keeping old fields working?

I know that a lot of this is theoretical, since there aren't all that many wind turbines that are old enough to need to be replaced.

And I'll give my consent to any government that does not deny a man a living wage-Billy Bragg

by ManfromMiddletown (manfrommiddletown at lycos dot com) on Sat Feb 27th, 2010 at 02:49:04 PM EST
[ Parent ]
As you state, at this time it's all theoretical.  Offshore we just don't know.

Onshore there is evidence that towers and foundations can be reused, but still uncertain, depending partly on site conditions.  One problem is that new load factors and frequencies change tower dynamics.

I expect an entire recycling industry to evolve, and good sites to stay in service.  For offshore it's perhaps too early to understand properly.

"Life shrinks or expands in proportion to one's courage." - Anas Nin

by Crazy Horse on Sat Feb 27th, 2010 at 03:21:34 PM EST
[ Parent ]
The reason I ask is because I've been thinking about this stuff that came from D'Arcinoff.  If you take them seriously, they plan to have make the equivalent of 3-4% of US electric production annually.  Regardless, there's going to a saturation point as some time in the future, when the industry is mature.  I suppose what I'm wondering is what happens then?

Is there going to be a continuing need for new turbines to replace old ones in the field?  Are old foundations going to be reused? If that's the case the engineering and construction side is going to fall off massively.

I'm planning to go to the  US Social Forum in Detroit this summer, and I think that I may try to see if I can put together a panel of people who can do something on the potential for wind power in the Great Lakes.

One of the other things I've been thinking about is the impact of all these new electric cars coming out on the need for electricity.  Let's say that 100,000 Chevy Volts are sold in 2011.  With an 8 KW battery that will need to be charged daily, that's 800,000 KwH daily.  Nominally, that's 33-34MW of new nameplate capacity needed.  Figure that most of that charging will happen during 8 or so hours at night, and it's more like 100 MW nameplate.  Figure in downtime and capacity factors (I think that's the word I'm reaching for) and you're talking about a new, decent-sized coal fired plant needed.

But imagine if you could work with utilities to sell people green power for their cars.  Like a large up-front payment for a set period like 5 years.  You could use it to finance new wind projects.  Figure $0.15/ kwh (I'm putting the cost real high.)  So that's $1.20 a day, $438/year, $2190 for five years.  If you could sell that to even 5% of those new purchasers, that's about $11 million year......  I wonder if something like that could work. hmmm....

And I'll give my consent to any government that does not deny a man a living wage-Billy Bragg

by ManfromMiddletown (manfrommiddletown at lycos dot com) on Sat Feb 27th, 2010 at 04:26:07 PM EST
[ Parent ]
But imagine if you could work with utilities to sell people green power for their cars.  Like a large up-front payment for a set period like 5 years.  You could use it to finance new wind projects.  Figure $0.15/ kwh (I'm putting the cost real high.)  So that's $1.20 a day, $438/year, $2190 for five years.  If you could sell that to even 5% of those new purchasers, that's about $11 million year......  I wonder if something like that could work. hmmm....

I think you need to talk to Chris Cook - LOL

En un viejo pas ineficiente, algo as como Espaa entre dos guerras civiles, poseer una casa y poca hacienda y memoria ninguna. -- Gil de Biedma

by Migeru (migeru at eurotrib dot com) on Sat Feb 27th, 2010 at 04:33:37 PM EST
[ Parent ]
He did, via linked in, but we somehow missed each other, as although I'm technically a member, I don't use it.

"The future is already here -- it's just not very evenly distributed" William Gibson
by ChrisCook (cojockathotmaildotcom) on Sat Feb 27th, 2010 at 07:39:43 PM EST
[ Parent ]
There are some examples of financing where the utility prepays x years of expected energy upfront, in effect playing an equity role.  Haven't been involved in one of these deals, so can't examine the details.  In the US, utilities can also take the PTC directly.


"Life shrinks or expands in proportion to one's courage." - Anas Nin
by Crazy Horse on Sun Feb 28th, 2010 at 04:59:15 AM EST
[ Parent ]
There's an interesting article in the latest edition of the IEEE power and energy society magazine (v. 8, n. 2, March/April 2010) about the comparative performance of windmills and conventional power plants under transient conditions.

According to the article, in early days, wind generators were simply tripped off line if there was a voltage transient, because the power companies didn't want to deal with their unconventional characteristics and there was so little wind capacity on the grid anyway. Then, as the fraction of wind power grew (in Europe, first, and then recently in New Mexico where the grid can get 20% of its power from wind under some conditions) it because necessary to actually solve the problem of making the grid work reliably with a mix of conventional and alternative energy sources. Finally, the U.S. Federal Energy Regulatory Commission adopted the German E.ON Netz Fault Ride-Through (FRT) specification.

It turned into a bit of an argument, because the FRT spec was tough for the wind generators to meet, and their manufacturers thought they were being discriminated against, while the conventional generator operators thought that the windmills were being given a break. The crux of the argument is that the specification required the generating plant to ride through 0.625 second faults where the line voltage has dropped to 15% of nominal. What it doesn't do is require ride-through of any amount of zero line voltage.

The conventional machines want a load, and when the line voltage drops, their load drops and the machinery speeds up. The system can ride through a very short period of zero line voltage, but if it drops to 15% for more than a second or so, the generator shaft gets too far ahead, the system loses synchronization, and the protective circuits trip it from the grid.

The windmills have variable speed shafts (depending on wind conditions), and the AC characteristics are controlled by electronics. So while it's expensive to add the capability to ride through a drop to 15% voltage, when you've done it, you can ride through much longer failures.

So now the problem boils down to the fact that the new windmill systems have the ability to handle the new FRT spec, but the older conventional systems don't--and it's really hard to retrofit them. All sorts of mechanical systems like lubrication, feedwater pumps, cooling systems, fuel compressors, active seals, etc. are all very sensitive to power fluctuations and have protective circuits that trip if there's a line fault. It's not that the technology is unavailable, it's just that it's not factored into the cost of the plants because it wasn't included in the original system.

It's kind of a weird problem: You want to improve the reliability of the grid while adding new power sources, but when you do so it exposes shortcomings in the existing physical plant. This makes it tough to calculate the relative cost of the systems, because even if you eliminated wind from the equation altogether, you're still stuck with these old plants that suffer nuisance trips all the time.

Note: I don't actually know anything about this, I'm just summarizing the article...  :-)

by asdf on Mon Mar 1st, 2010 at 11:00:55 PM EST
One thing you can do with older windplants with pre-FRT technology is... leave them alone.

When they trip, they reset and come back online.  No biggee.  They aren't a grid problem at all in current numbers, and since new turbines have more sophisticated electronics, the penetration doesn't expand.

"Life shrinks or expands in proportion to one's courage." - Anas Nin

by Crazy Horse on Tue Mar 2nd, 2010 at 10:29:52 AM EST
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