http://environment.nationalgeographic.c ... ctive.html

This is very informative.

Me! But the link doesn't work.

Didn't for me either...thanks for getting me all excited Steens...you big tease!

It works now, you guys sure?

it opens..there are 3 related picks on top...but the words never show up...probably a update that needs to be done on my 1968 work computer

It is a interactive program not an article. You have to click "How it works" the green button. Then you can learn a little and then play with settings to create more or less power based on all the available inputs.

If you do not see anything between the three pics at the bottom and "Harness the Power of Wind" at the top you probably do not have java installed.

Steen... What I want to know, honestly, is why the hell do they move so slow? It seems that even in high winds these things move like turtles. Why don't they use a greater surface area and/or get the turbine speed up?

What are the blades made out of?

How fast do you think those blade tips are spinning? I'll answer after that is answered, it's fun.

They are almost all made of fiberglass. Some mix steel of frame like an airplane wing with fiberglass... but 90% more more are fiberglass.

I think you're going to want to throw out some big MPH figure, but I'm not allowing it... Why? Because the circumference is huge... I will say that I don't think they're spinning faster than 60-70 rpms...

The large MW ones are almost up to 200 mph, but they are really only going 15 rpm.

The reason is that we try to create torque, not speed. Those blades have a HUGE mass. But we use a gearbox to increase the speed before it gets to the generators. If those blades spun much faster they would shake the structure till if exploded.

Check out this video of a turbine in overspeed...

Physics will not allow it on the larger wind turbine...

http://www.youtube.com/watch?v=ti1ebjLephE

I KNEW YOU WERE GOING TO GIVE ME SOME BS MPH!!!


That is a sweet video... It seems to me though that there should be some happy medium... I'm not saying that these things should do 200 rpm, but they move so damn slow, even when it is windy... It seems to me that they're engineered WAY on the safe side and could be out double or triple the amount of power if they were allowed to (or made to) spin faster.


I wouldn't mind seeing a brake or governor that kept them below a certain RPM, but it is maddening to see them slowly laboring along whether the winds are 10mph or 30... They seem to spin nearly the same in any wind condition....

What you are not getting is that speed does not equal power. TORQUE equal power and we actively control the amount of torque to produce more power. We increase the amount of torque by increasing the current in the system. Voltage relates to speed. We do not need more voltage to get more power, but rather more current to get more power.

We could let is spin faster by reducing the torque being created, but then we would be making LESS power. They actually do spin relatively the same in all wind conditions because they are designed to increase the power production, which means increased torque, as the wind gets higher. You are switching voltage and current in your thought process.

These things are not over engineered, in fact most would say they are under engineered as most to date do not last their designed lifetime. Blades break, gearboxes don't meet design life, etc.

I understand what you're saying now... You're basically saying that as they would spin faster you gear them down to create more torque (more or less spinning faster at the other end of the gear box, rather than at the blade). I'm cool with that, I just didn't know that they had that technology built into them.

As far as parts breaking... There is a difference between engineering something on the safe end of its power/speed rating, and engineering something with a crappy gear box and parts

Right now... crappy is the new in...


But there is more involved here than current engineering practices know. Traditional engineering practices do not fit with you are working on something so big and different. I believe we are going to learn a lot more about gearboxes and the technics used to design them from wind turbines. It just is so different than past practices, sizes, and uses.

You'd also be surprised by all technology that goes into these things. We control the blade pitch angles to increase or decrease the torque available. We actively control the power created to match so we do not stall. We actively control the direction of the turbine. We have service lifts in the towers. It goes on and on... super interesting, I was amazed when I started.