I hadn’t intended my post to advocate protectionism; I was just pointing out the hypocrisy of the left in their mantra of “buy American” as their purely union protectionism. When I encounter someone wearing a “Buy American” T-shirt or sticker, I ask them if that includes crude oil? I have not yet received a printable reply.

Just about everything you say you get wrong.

“Just where is the magnetic field coming from? A magnet.”

Ever hear of an electromagnet? That’s what nuclear power plants, hydro plants, coal plants and natural gas plants use.

Two brands of big turbines use doubly fed induction machines. These have both the rotor and stator wound with a three phase winding. The rotor is fed from a three phase inverter to generate a rotating field.

The rest use induction generators.

http://en.wikipedia.org/wiki/Induction_generator

In an induction generator the field is applied by the grid.

“Steel magnets are possible, yes, but .. much less strong than rare earth magnets, and the stronger the magnet, the smaller it has to be.”

The best commercial magnets have a field of 1 Tesla. The field strength in a generator made from steel and copper typically runs around 1.6T.

“Not sure about the big turbines – do they do the generating at the head (i.e. a couple stories in the air) to avoid mechanical loss if they were to, like old farm-style windmills, spin a drive shaft and put the “work” (i.e. generator, pump, lathe, whatever) at ground level?”

The generator is up in the nacelle. Along with the gearbox, controls… everything except the step up transformer.

“If they’re putting the generator in the head, right behind the blades, to minimize mechanical loss, then they almost have to be using rare earth magnets. Anything else is just too big.”

They have a two or three stage gearbox between the generator and the rotor. The rotor spins around 12 to 15 RPM. The generator spins at 1800 RPM.

Ever see a nacelle? They are bigger than you think (and higher up than “a few stories” – try about 50). Because of their height you don’t realize how honking big they are. The generator itself is about 5′ in diameter and about 8′ long.

But I can demonstrate evidence combining some links.

I suspect where the whole permanent magnet story comes from is that some of the turbine manufacturers are looking at new versions using permanent magnets. That will be in the news, but doesn’t represent what most of them use. GE for example has one of it’s 4 models with permanent magnets: but the numbers are over 14,000 without and 35 with. If the magnets go away they can just keep making the other 3 that already represent almost everything they make anyway.

Now for the links…

Mitsubishi is permanent magnet free:

http://www.mpshq.com/products/wind_turbines/index.html

The data sheets are linked to on the lower right of that page.

Their 1 MW machine has a “induction generator”. Their 2.4 MW machine has a “doubly fed asynchronous generator”

If you’re a purist, go to a technical library and check out an electric machines book. Otherwise, we have wikipedia:

http://en.wikipedia.org/wiki/Induction_generator

http://en.wikipedia.org/wiki/Doubly-fed_electric_machine

Neither article mentions permanent magnets; that’s because neither of these electric machines uses magnets.

Now for GE:

http://www.google.com/url?sa=t&source=web&cd=3&ved=0CCQQFjAC&url=http%3A%2F%2Fwww.gepower.com%2Fprod_serv%2Fproducts%2Futility_software%2Fen%2Fdownloads%2F09100_Modeling_of_GE_Wind_Turbine-Generators_for_Grid_Studies.pdf&rct=j&q=GE%20doubly%20fed%20wind%20turbine&ei=Ar_LTJLEN5LCsAO_wvmIDw&usg=AFQjCNE_TE0NpFkutypLYAsjiOPqCGvrSA&cad=rja

1 model with magnets, 3 without. And as I noted above, they’ve sold 35 of the magnet using model, over 14,000 of the non-magnet model.

Vestas is the other huge manufacturer. Unfortunately I’m unable to come up with links, but they too are permanent magnet free.

“If I perpetrated a falsehood, then my apologies, but I did cite a source.”

No need to apologize. My word was very carefully chosen because I do not believe that you did anything intentionally dishonest. I greatly appreciate your contributions to the energy topics here.

“The New York Times may not be the world’s most credible source”

Yep. What’s the track record on petroleum extraction? I bet reading an article from them on the subject seems to miss the mark terribly.

What irks me is their nuclear coverage because I am a true nuke fan.