World's Largest Wind Turbine 445
PeteJones writes "'Construction work on the REpower 5M was successfully completed last night with the installation of the rotor. Thus the main work on the prototype of the 5-megawatt, world's largest wind turbine has finally been completed.' The pictures are quite impressive. With 3 18-ton rotor blades pumping out 5 MW I wonder if my neighbours would mind one in my backyard?"
Images mirrorred in anticipation.. (Score:4, Informative)
http://www.biggleszx.com/slashdot/5m_02.jpg [biggleszx.com]
http://www.biggleszx.com/slashdot/5m_03.jpg [biggleszx.com]
Regards.
Re:Images mirrorred in anticipation.. (Score:2, Informative)
Re:Wind Requirement (Score:2, Informative)
More significant than maximum spin is what the minimum is before it makes power.
Speed range quoted from their web site is: 6.9 - 12.1 1/min (+15%)
How much wind does it need to hit the minimum RPM I wonder?
also:Couldn't help but notice this line from the companies front page: "Proofen Technology in New Dimensions"
Should a company that can't use spell check be building something this big?
Coralized (Score:3, Informative)
Great idea, wish the U.S. had more of it (Score:5, Informative)
This [saveoursound.org] is an example of the obstacles that American power generating windmills are facing. If ever there was a NIMBY group it's these people. Someone wants to build an offshore set of windmills to power [boston.com] about 3/4 of Cape Cod and surrounding areas in Massachusetts. Since Massachusetts is heavily dependent on important electricity and oil, this seems like a great solution.
Undoubtedly there are some ecological implications, but the NIMBY group clearly is magnifying these issues in order to shoot down the whole idea; they're fishing for excuses. They don't want to have to look at windmills. This is where some federal leadership may be required in order to get the U.S. off its foreign energy dependency.
Re:Wind Requirement (Score:2, Informative)
Re:I hope the noise isn't too bad (Score:5, Informative)
In the end, my idea is probably the easiest. But it won't be 100% effective. It is best to locate large-scale turbines away from areas where sound will be a problem.
Re:World's Largest Wind Turbine (Score:3, Informative)
Well, (Score:4, Informative)
And thats the cost to buy the thing. Meaning materials, employees, as well as power in production. I don't see how you can say the power required to make it would be more then the power generated. I mean, unless the manufacturer were getting power for free, which is pretty unlikely.
Windmills are simpler then most other kinds of power plants too.
Now, i've heard that solar cells have this problem, though.
Re:Wind power efficiency (Score:3, Informative)
The latest copy (number 48, page 24) states that it takes 2 to 4 years to recoup the electricity required to produce photovoltaic cells. Fortunately, they do on average last about 20 years, so you do get an 'energy gain'.
You can safely assume that the same is true for wind power which is also a 'low energy density' device that will take a long time to pay itself off.
Re:Wind Requirement (Score:3, Informative)
It has been eons since I was into wind turbines, but there are 2 approachs. One is too simply feather the blades. That is lower the angle to the wind. The blades still turn, but present a much lower surface area to the wind.
The other is to feather the turbine itself. It has the problem that it decreases the speed, but it is easier since the blade attachment does not require special consideration.
Re:Way to make safe for birds? (Score:3, Informative)
The speed of the blades isnt what kills the birds, its their own speed they have while smashing into a steel tower.
If you want to save birds, ban cats....
Re:Wind Requirement (Score:4, Informative)
Are you referring to the fact that there are just three blades on this machine? If so, there were studies done in the 1970's as to what configuration was most efficient. Three blades turned out to be the most efficient. The old fashioned areromotor designs that were on early 20th century farms were not very efficient. Much less efficient than the modern three blade designs.
Re:Wind power efficiency (Score:3, Informative)
Re:Wind Requirement (Score:3, Informative)
"The guided tour [windpower.org] is written for people who want to know a lot about wind energy, short of becoming wind engineers."
For anyone with a long list of questions they think will be best answered by posting them on slashdot, the windpower.org website has enough to keep you occupied for the rest of the evening.
Power output calculations here [windpower.org] - remember it's statistical, so don't just assume constant wind speed and multiply it by the average weight of air
Re:Wind power efficiency (Score:5, Informative)
As regards taking energy out of the wind, the atmosphere's about 11km high, and the wind profile goes up from zero at ground level to pretty fast up in the jetstream. A turbine's wake is mostly dissipated at about 8 turbine diameters downwind, too. So even a wind turbine of this size might only affect less than 1% of the total atmosphere's height, for less than a kilometre horizontally.
Re:Wind Requirement (Score:2, Informative)
http://www.gepower.com/prod_serv/products/wind_
rbines/en/36mw/index.htm
Check the PDF docs and they have nice curves of how much power is generated at what wind speeds.
400kW @ 5m/s (11mph for the metric challenged)
up to 3.6MW @ 14m/s (31mph)
Optimal wind turbine size (Score:5, Informative)
When wind power started to come back after the 1973 energy crisis, useful sizes were much smaller. There were a few big machines, but they were one of a kind prototypes. Most of the turbines of the 1970s and 1980s were in the 100KW range. That's a convenient size, because all the components can be shipped easily. The entire hub/generator unit can be shipped assembled.
But all those little turbines are a maintenance headache. Farms of big mills generate more power per acre than little ones, because the blades are higher and catch more wind. So size has been creeping up. As the 1970s units wear out, they're being replaced with fewer, but larger, machines. New wind farm machines are running around 1.5MW. That's a commercial technology. General Electric alone has 2300 units of its 1.5MW turbine [gepower.com] installed.
Offshore, much bigger machines are the norm. Setting a pylon in the ocean is a big job, so the fewer the better. Big components can be moved in by ship, so the truck size limit goes away. So offshore machines are running around 5MW. But there aren't many of them. Most of the really big machines are still experimental.
Wind power is like hydroelectric power. There are a limited number of good sites. Most of the ones in California, the major passes through the coastal mountain range, are already taken. The East Coast doesn't have a long coastal mountain range, so installing wind farms in passes is out. So the East Coast systems tend to be offshore.
Total installed wind turbine capacity worldwide is about 40 gigawatts, although that's peak, not average, output. This is up by a factor of 10 in the last decade. Much of this is due to better power conversion technology. Early wind turbines synchronized the blade itself to the power grid. Newer ones have inverters and better controls, so they interface much better to each other and the power grid. Many of the early turbines were only tolerable on grid because they were such a minor portion of generation. They were a destabilizing influence, forced into synch by bigger generators elsewhere. With improved controls, wind generators can contribute to frequency stability, rather than stressing it. As wind power becomes a larger fraction of generation, that's essential.
Re:World's Largest Wind Turbine (Score:3, Informative)
We would drive by this house a few times a month, and over the course of many years we never saw the windmill rotating once - the blades were always in the same position.
We always assumed the gearing was wrong, or they were trying to push too large a generator for the wind conditions in that area.
Regardless, it was obviously a very large waste of money. It certainly demonstrated that one should do some serious research and weather studies before attempting wind power.
Dan East
Re:Wind power efficiency (Score:1, Informative)
You do realise that if this was even remotely true all that diesel (which is the fuel we're talking about here) could be put to much better use turning generators instead of cranking mining equipment (and whatnot).
In truth nuclear emits about 40 g co2 per generated kwh. A coal fired plant releases about 900 g co2 per generate kwh. Renewable sources are at about 10 g co2 per generated kwh.
Now, the reason nuclear generate so much co2 is because of the mining operation. Uranium is spread pretty thinly. This mining operation could be converted to use electricity with few problems (mostly confined area, could run with wire/cable feeds, this has/is already done in other mining situations). Major transports could be done by rail (electrified rail) thus almost eliminating co2 emissions from the nuclear equation.
The reason this is not done is simply cost. Diesel is still to cheap (i.e. co2 emissions aren't expensive enough) for anybody to want to take the conversion cost. But if we wanted to reduce co2 from nuclear that wouldn't be too hard to do. Reducing it from coal/oil is a whole other kettle of fish.
300MW facility in Washington/Oregon (Score:4, Informative)
Granted, each turbine is only 660kW -- far short of the 5MW of the turbine mentioned above -- but all put together, with 454 turbines, it makes for a sizeable facility. Plus with lease payments of $1500-2000US per turbine, it provides farmers with their biggest cash crop since marijuana.
Yes, there's photos [rnp.org].
Re:Huh? You mean NUCLEAR, dont't you? (Score:3, Informative)
Re:Optimal wind turbine size (Score:3, Informative)
I must say, I find this assertion pretty ridiculous.
I happen to live in CA, and I've seen a couple wind-turbine fields. The fact of the matter is, there is a huge desert here, meaning both that there are no trees or anything of that sort to get in the way, and the tempurature contrasts are very extreme in a short area. I know from just living here that strong winds are both regular and nearly hurricane-force. The ammount of land available, with intense winds all the time, is mind boggling. If you drive by any of the wind-turbine sites in the desert, you'll also see that they aren't anywhere special either... Nothing would stop you from just expanding the existing fields out for miles, and miles, and miles.
Not very big... (Score:5, Informative)
If you can find a way of levelling the load (e.g. batteries) with only moderate conservation you'd need the equivalent of a constant 1kW output, about 1.4 Hp. Power abstracted from a windmill follows the formula k*0.5*A*V^3, where A is the area of the blade disc, V the windspeed, and K is the fudge factor. There's a theoretical limit of about 59% efficiency, due principally to retaining enough momentum to carry the air on the downwind side away from an axial turbine.
Anyway... say you have a mean wind speed locally of 10mph, which is constant, because you have the device up a tower. That equates to 4.45ms^-1, so working backwards, and assuming 50% efficiency for the 'k' factor - hey, we're geeks, we'll buy th every best - you'd need a blade disc, um, 5.4 metre diameter. Of course the conversion to electricity incurs losses, sy 80% overall... so a (*very* efficient) wind genny rated for1Kwh output at 10mph would imply a 5.9m diameter swept area. Pretty small!
In fact, in the interests of minimising noise and improving part-speed efficiency, you'll find 1kW rated wind generators are slightly bigger, and rely on rather higher mean windspeeds. Beware the windspeed measurement though, that V^3 term will kill ya. If the mean windspeed locally turns out to be just half what you measure, you'll get, at best, only 1/8th the output expected. The actual design considerations for wind turbines (disc solidity, operating range windspeed etc) are wonderfully technical and pretty interesting in their own right.
As to why not...well small wind gens are rather expensive , and Planning control (local ordinances, US) tend to restrict the possibility to rural areas.
Re:Unfortunately, birds save weight on brain... (Score:5, Informative)
Re:Wind power efficiency (Score:2, Informative)
1) Go outside. Find a cement wall. Push on it as hard as you can for 10 minutes.
2) Go outside. Find a compact car. Push it up a hill as hard as you can for 10 minutes.
Are you telling me that you exerted less energy on the wall solely because it didn't move? Rubbish.
I agree completely that we shouldn't just jump into global wind farms that cover the earth and expect there to be no side effects. But that is very unlikely to happen on a scale that really affects the environment.
Now compare that possible outcome to the very real outcome we are already experiencing today with heavily polluting power plants and the accumulation of nuclear waste.
Until something better comes along, I'll gladly take my chances on the wind power.
The threat of signifigant change to the polar ice caps and ice shelves, and the very, very rapid (in the scheme of things) change to the environment they will and are bringing are a clear and present danger to all life on earth, and I think far outweight the effects of slowing down the wind a little while at the same time repairing the existing environmental damage.
With all the diverse landscapes, plants, and buildings that cover the earth, I highly doubt any amount of windmills that will be built could have any noticeable impact, even globally, even in the long run.
I appreciate the formulas, I just strongly disagree with the analysis. Wind power is far preferable to anything but solar, and solar isn't feasible on that kind of scale right now.
Fairly audible... (Score:4, Informative)
A local guy filmed it in action, and you can hear just how audible these things really are:7 83.avi> [wigleyandassociates.com]
<http://www.wigleyandassociates.com/uploads/MVI_6
Re:Wind power efficiency (Score:3, Informative)
I refer you to a paper like this one [soton.ac.uk] to confirm for yourself that if you talk about heat and energy transport in the atmosphere you are talking in terms of PW that is Petawatt i.e. 10^15 Watt. The energy stored in the atmosphere is many magnitudes larger than the current 0.013 PW of global human power consumption (the average power consumption is about 2000 W per person [novatlantis.ch] i.e. given there are about 6.5x10^9 [ibiblio.org] people on this planet you get the 0.013 PW number).
If you take into consideration that the mass off our atmosphere is 5.1 x 10^18 Kg [wikipedia.org] and the heat coefficient of our air is about 1.005 kJ/(kg K) you can easily verify that an increase in atmosphere temperature by one degree Celsius stores about an additional 5125500 PJ in the atmosphere.
That means even if all of the given the current world power consumption was to be drawn out of the atmospheres it'll take more than 12 years to just get the equivalent of one degree change. Given the current inverse trend in global warming that'll be actually quite welcome.
This is of course just a quick and simple back of the envelope calculation but it should give you an understanding of the magnitudes involved and lay any doubt at rest that some windmills could potentially affect the world climate.
Really don't know what to make of the parent post. Suspect for a second that this was just astroturfing but then the posting history doesn't support this. Wass even claims an undergrad degree in physics. He really should know better.
Re:nuclear CO2 (Score:3, Informative)
What I'd really like to see is a functional fusion reactor. Until fusion reactors are a reality, nuclear power will never get past the combined burden of phenominal expense + the "now we've got to find someplace to safely store the waste, who wants to volunteer" factor.
Re:I hope the noise isn't too bad (Score:3, Informative)
Re:Wind Requirement (Score:3, Informative)
The turbine will turn itself off. It won't allow it's blades to go too fast.
Turbines have a cut in and cut out wind speed, which are wind speeds in which the turbine will turn on and off. The turbines I have studied will turn on at 3 m/s windspeed, and turn off at 25 m/s.
Of course, the wind speed also dictates how much energy will be created. A 3 m/s wind speed will generate a lot less energy than 12 m/s. Also, the energy creation is a bell curve, so wind speed higher than optimal will also have reduced energy output.
Energy output is not gauranteed to be what the turbine is specified for. The site's wind speed and temperature fluctuations throughout the year will be what actually determines the energy output. Also, one season could produce a lot of energy, while another season won't produce much energy at all.
You can use this calculator [windpower.org] to play around with different turbines and different site attributes to see how much energy will be output. You can then use this website [awstruewind.com] to find out the wind attributes of your area, so you can find out how much energy a turbine would produce if it were in your backyard. (New Yorkers [teamcamelot.com] and New Englanders [teamcamelot.com] have more detailed wind information available, right down to your GPS coordinate!)
I programmed a 5-axis robot for the Turbineblade (Score:2, Informative)
When I first started out walking among the moulds for these wings its mind-boggeling how big the become. At first I thought 39mester was big, but the 61m meter turbineblade is incredible.
And think about the amount of engergy that a wing is loaded with, when you do a DESTRUCTIVE load-test (I dont think they actually do it on the 61m - but its normally how you test a blade) - KAPOW.
Windturbines really is an impressive industry - something we danes can rightly be proud of.
And the future ramifications of their use makes it even more interesting to be working in the field.