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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?
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 ##
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 I am sure it could be done for a specific installation that was poorly design, or used outdated techniques (like those horrible inefficient copper photovoltaic cells).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?
Wow. That's enough to power a small town. How much noise would a thing like that make?
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.
>> The East Coast doesn't have a long coastal mountain range, so installing wind farms in passes is out.
A thoughtful post, but uninformed on this point.
The Allegany Front in WV/MD/PA has been called the "Saudi Arabia of wind." (Turns out this is an overused marketing phrase.) However basically winds comes blasting off the Great Plains and nails the AF causing much snow and windy conditions. I ski there (Canaan Valley, WV) and it is really something - it is hard to believe such snowy and crazed wind conditions exist so "far" south.
There are several big wind farms there - the one outside of Davis, WV is a monster. The ones planned (Backbone Mountain WV/MD 65MW, Mount Storm WV 105MW, Dans Mountain MD ??MW) will be giant. There are others - Flat Rock NY 75MW. Hoosic Mountain somewhere in PA - I don't know how big, and The windform in Somerset is being enlarged.
So don't write off those east coast wind farms!
I am very small, utmostly microscopic.
The present kite heigh record is 13,600 feet , so we are still below the jet streams. The record kite is far too light to carry a turbine, but of course we could try to scale everything up :)
Finally I think that there is an element of safety involved (especially in these days of terrorism), and I don't if the jet streams are sufficiently stable.
Those are called vertical axis rotors, a variant of the savonius rotor. I've seen a few, they work well enough for a project any back yard handy dude can build. Usually they used truck differentials and axles, then some more pulleys, for the gearing to the alternator to get the speed up enough from the pretty slow turning oil drum halves.
There are some large commercial examples of them now also. I remember seeing a link to one company in wyoming that makes and sells them, but I have forgotten the name or I would provide a link to their page. IIRC, they look like big towers with wind openings, totally different from the airplane propeller blade looking projects.
Personally, I'd love to see a lot more R & D work on using atmospheric static electricty potential, I think it would be a serious contender in the alternative energy market. I like the idea of no moving parts whatsoever. I've read some on hobbiest experiments with them, some guys are getting useful amounts of juice from it, using wrapped bundles of stock fencing to act as the static accumulators in effect, and automotive coils as capacitors, then going to an opened up severely (large electrode gap) spark plug, then to a storage battery. Wind blowing over the fencing induces a slight charge, when it reaches potential to work the coil and spark, it jumps, gets into the battery in a series of very high voltage but low amperage pulses. Interesting concept. I'm not an EE, but that is my understanding about how it works.
they work very well as long as you can deal with the corrosive nature of the acids that get produced along with the methane gas. there's a very large example at a poultry farm near me that was running one for awhile and it worked well, but it corroded too quickly. Different materials and processes are needed for very long term operation.
I built a very small test digester one time, worked well, got useable gas. Just used junk parts I had kicking around, a washtub, a cut off oil drum, some milking machine parts, and some manure and water. all I ever did with the gas was accumulate it in plastic bags and set it off for people to see that that it worked. took me well under 1/2 hour to build it, too. Kinda a fun project, I'd like to build another one sometime, just at a useable scale for something..
Another time I built a really good hot water maker. Basiucally a variant on leaving a hose out in the yard on a sunny day, but I got the heat source from aerobic decomposition. The concept was simple, we had a big storm locally and woodchips were free for the asking from the power line crews because they had so much of the stuff, so we got some. I buried a few hundred feet of garden hose in the pile (all my spare sections on hand, this was just an experiment). As the stuff started to compost out, it got pretty hot inside, you could get a small stream of 160 degree water from it, pumping in cold at the entrance end, as long as you kept the pressure low enough. this was in the *winter*, too, BTW. Seems like you could build a closed system with something like that, using an antifreeze solution, high temp hoses, and radiators, put the whole thing downhill from you, let thermosiphoning pump it to where you needed the heat, radiate it out, the antifreeze cools down, falls back downhill to get reheated in the pile, where it gets reheated, starts working it's way back uphill, and etc,so you would have free heat 24/7 for as long as the chips held out, then use them for mulch someplace and replace them with fresh chips (or other compostable matter).
I LOVE this whole energy subject, too much fun, too many places joe backyard tinkerer can have fun and do useful projects!
First you consider the cost of setting up a silicon zone refining plant and assume that microchips do not exist, so you can't use an existing plant. Then you consider the cost of mining the sand, and deoxidising the silica, which takes a lot of energy, and once again assume that it is not being done for any other purpose (like making aluminium alloys for the last century), so you have to start from scrach. Then you consider the fuel costs for all the equipment, and factor in all the costs for oil exploration and production. By this point, any answer you get is going to be higher than just using oil or coal (and nuclear is a conpletely different steam generating kettle of evangelistic types who will hear nothing against the one true energy, which will break even some day soon once the greenies get off their back) - so this cheap trick always works - but is never relevent.