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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?"
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 ##
Wind required to spin is probably very little, ie, it would have to be very nicely balanced, and, once you got it moving (remember there is a total of 54 tonnes of blades here!!!) the rotational momentum must be incredible.
What would be interesting to know is, how much wind is needed to produce 5MW!? Someone feel like doing the physics to work out how much wind would be required to hit a disk 1/2rd of this size (roughly - aviation theory, it is why you feather dead props, windmilling a dead prop produces the drag of a disk about 1/2 it's size) of that size would be required (at 1013Hpa sea level of course) to produce 5MW at 100% efficiency.
Also, if you want to see prettier pictures, I advise you to wait a couple of days, then come back and take another look - they have already changed them to smaller different ones in the "brace yourself Shiela, it is pissing slashdotters" frame of mind.
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 I am sure it could be done for a specific installation that was poorly design, or used outdated techniques (like those horrible inefficient copper photovoltaic cells).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?
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.
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.