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World's Largest Wind Turbine
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?"
How much wind does that thing require to spin?
Yeah... I bet the bird collector down at the bottom is quite large.
A while ago (with a previous generation of wind turbine technology, for sure) someone built a particularly large wind turbine on one of the windier islands of Scotland's west coast, hoping to replace (or lessen) expensive shipments of fuel oil. Power production was fine, but the locals were driven to distraction by the noise the thing produced, particularly when the windspeed was high. I believe it produced a very loud "whump" every second or so, loud enough that no-one could sleep. I believe the conclusion to which the developers came was that very large turbines were prone to this problem.
Still, that was a while ago (maybe a decade) so I'd imagine the developers of this new megaturbine will have engineered out the "whump" issue.
## W.Finlay McWalter ## http://www.mcwalter.org ##
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Regards.
$ mv *.sig >/dev/null
With 3 18-ton rotor blades pumping out 5 MW I wonder if my neighbours would mind one in my backyard?
This is Joe from down the street.
Please.. just please, stay in your mother's basement, you creep.
If that's becoming less true, I think this is a great thing. I worry a little about the environmental effects of "taking energy out of the wind", but I haven't read about anyone important who shares my worry, so it's probably unfounded.
The whole of Europe was once covered with forests. Now most of it is covered by farmland and urban areas, which offer less resistence to wind. If anything, those windmills will bring back more "natural" conditions.
Sounds like typical anti-wind propaganda. Its funny, every time this argument is brought forth for wind or solar, someone says 'I just read it somewhere' - I have never seen hard figures to support such a critique of the economics of alternative energy. I am sure it could be done for a specific installation that was poorly design, or used outdated techniques (like those horrible inefficient copper photovoltaic cells).
If that's becoming less true, I think this is a great thing. I worry a little about the environmental effects of "taking energy out of the wind", but I haven't read about anyone important who shares my worry, so it's probably unfounded.
If only we could slow down some of those winds, I am sure a lot of people who just suffered from hurricanes would be rushing to install wind turbines! But no, the amount of wind taken by even the largest turbines is so infinitesmal as to not matter. It would be like fretting about contributing to global warming each time you farted, to worry about these machines causing environmental damage by calming a windy area.
How big would a Wind Turbine have to be to power a house? Some people already have solar panels on their roofs, why not a small Wind Turbine?
Some nerd is thinking, "where can I get THAT kind of power for my beanie....."
Click here or a puppy gets stomped!
This is a great idea. Why aren't we fully exploiting the power of the wind?
This 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 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.
it's = "it is"; its = possessive. E.g., it's flapping its wings.
I know that for smaller windmills, say the 1-5kw models you can buy online would pay for themselves in saved electrical bill cost in about 5 years.
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.
autopr0n is like, down and stuff.
Friends don't help friends install M$ junk.
If anything, those windmills will bring back more "natural" conditions.
Minus the part with whirling steel blades that regularly vivisect birds and flying mammals you mean?
-- No matter how great your triumphs or how tragic your defeats, approximately one billion Chinese couldn't care less.
Wind in the southwestern deserts and midwest plains away from most everything else. Solar would work in the south in general. Hydro in the north. If you take NYC (niagria falls), SoCal (solar and wind), Boston (from QuebecHydro)Texas (solar and wind), Flordia (solar) you are 25% of the way there. That is a big cut. Should drop existing energy prices and reduce greenhouse emissions as well. Add in some good insulation and, while you dont have the problem licked it is a big step in the right direction.
v(z) = v0 ln(z/z0 )/ln(z1 /z0 )
Here v0, z0 and z1 are constants. Here is a nice site about windmill engineering.
Birds shouldn't be hitting this since they can see it from miles away. Plus the fact that it's moving should scare them away. It's not like glass where they often can't see it and try to fly through it.
Unfortunately, birds tend to save weight on brain. B-( They don't seem to connect the passage of one blade with the next. When blades are big, and moving an an appreciable fraction of the speed of sound at right angles to the bird's flight path, they sometimes don't notice that there's another one coming until it's too late to dodge it.
Google for "windmills birds dead". Lots of info out there.
One estimate is 70,000/year in the US alone. Another is 44,000 for just Altamont pass. Another (in 1992, when there were fewer mills) put the Altamont Pass golden eagle kill rate at 39/year, and the total breeding population at 500 pair. More recent numbers put the kill rate for goldens at 60/year.
Golden Eagles, Red-tail Hawks, and Kestrels are at particular risk. They focus on their prey on the ground and ignore the blades. And there's a positive feedback loop: The shelter from raptors leads to a denser population of rodents near the mill, which baits in more raptors.
But other birds are not immune: Large wind farms tend to be set up in mountain passes, where the mountains concentrate the winds. But they also concentrate bird migrations, one of the factors focusing bird migrations into a few narrow "flyways". Birds tend to fly in flocks (to save energy by riding the vortices from the bird in front) and depend on their numbers to protect them from peredation. So even if the blades are noticed they may be ignored, and a flock may fly right through a windmill's swept disk.
The problem is mainly the large mills, whose blades turn at a slow rate (though still at a phenomenal speed) and which are too large to be perceived as a single unit. (I've never heard of any issues with birds related to the small, fast-spinning mills used for wind power on a home or farm level.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
And how long does it take until a coal plant has produced the amount of energy needed to build it? Or a nuclear plant? As a sidenote: I have read figures that building a nuclear plant produces more CO2 then it later saves during its energy production time (mining and enriching fuels, transportation of building materials, fuel and waste, storage of waste, security activities during transportation etc.)
The original poster claimed/implied, the energy usage in production was that hughe that it never would pay off energy wise. Thats simply wrong. For solar cells its wrong since 20 years. I would guess for wind energy it was allways wrong, except if you had chosen an idiotic production process, e.g. very small wind mill made from aluminium.
All ways of generating energy first eat a lot of energy in creating the power plant. Thats live, erm, such is our industry.
angel'o'sphere
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
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.
This site http://www.windpower.org/ which the danish wind generator producers have put up contains a lot of useful information about windpower and counters most of the FUD you'll hear.
Wind power is not perfect, but it is here now (as opposed to fusion energy) has no waste problem (as opposed to current atomics) has local and well understood failure modes (things break, fall down) Produce a lot of power when we need it most (wind is driven by energy from sunlight) and it is economically competitive.
The key to a sensible energy future is to not be fanatical for/against any one source, but to exploit them all where and how it makes sense.
Poul-Henning Kamp -- FreeBSD since before it was called that...
It usually takes longer for this unscientific, unfounded idiocy to pop up on a wind turbine story, but here you are. Congratulations. People like you make it clear you have never seen a wind turbine, have no concept of environmental conservation, and are just parroting anti-wind lies invented by people vehemently opposed to reducing dependence on oil.
BIG, SLOW MOVING BLADES DO NOT CHOP THINGS UP. PERIOD. The danger posed is extremely minimal. It's theoretically possible for a bird to run into one of the slim, slow-moving blades, and that would likely cause injury, just as if they had run into one of our fancy new all-glass-exterior skyscrapers. But more birds are killed every minute by deforestation and destruction of wetlands, than will be killed by this thing in its entire working lifetime.
Random and weird software I've written.
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 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.
The Stateline Wind Energy Center in SW Washington and NW Oregon has the capacity to produce 300MW of energy, one of the largest installations in the world to date.
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.
Give me my freedom, and I'll take care of my own security, thank you.
21045.09663 to 78167.5018 furlongs/fortnight
When the people fear their government, there is tyranny; when the government fears the people, there is liberty.
..but it depends where you are (local average wind speed, depends heavily on topography) and how much power you need.
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.
A local guy filmed it in action, and you can hear just how audible these things really are:7 83.avi>
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