If wind drives the sails of a wind turbine, why do the sails of turbines still move on windless days?

Question

I know how turbines work, but I cant work out why the sails of those huge wind turbines are always moving 1) at the same speed, and 2) even on days when there is no wind. How is the wind even strong enough to cause the blades to move?

Answer 1

1/ wind turbines has a device called a controller.
The controller starts up the machine at wind speeds of about 8 to 16 miles per hour (mph) and shuts off the machine at about 55 mph. Turbines do not operate at wind speeds above about 55 mph because they might be damaged by the high winds.
2/ the Pitch of the blades change with the speed of the wind
therefore the blades rotate at the same speed no matter how windy it is.

it only take 8 mph (some turbines only need 5 mph winds) winds to move the blades a gentle breeze would do it. the turbines are on towers which are pretty high in fact the higher the tower the more wind they get. so on ground level it could be windless however up there on top of them towers there could be enough wind to move the sails.

you most have all your Christmas shopping done to be asking such questions.

Answer 2

The sails will not turn if there was no wind.Next time you observe a Turbine look for the wind speed indicator, if this is turning then the sails might revolve. Even if the sails do revolve there will be no usefull power generated

Answer 3

Heat rises and causes enough positive air movement to make the sails move.
How does the wind cause the blades to move.The answer is simple yet hard to answer in a nut shell if the turbine shaft requires 100 foot pounds to cause it to move it would require a 100 sq ft surface area blade with one pound of pressure exerted upon it to give the 100 ft pounds to move the shaft.
100 sq ft X 1 pound air pressure per sq ft .= 100 foot pounds

Answer 4

Even when there is no prevailing wind, the air can still be moving more than two miles per hour. This may be due to locally-produced convections generated by heat from reflected radiation from the ground or structures.
Any air is considered calm below 2 miles per hour.

Answer 5

If there is NO WIND then nothing powered by the wind moves. I don't know how you think that wind machines operate without wind. NOT GOING TO HAPPEN.

Answer 6

they bave batteries that take some of the electiric that charges them and when they wind stops they turn on the battery so it turns the turbine , and when it does this it charges the spare batteries and then switch them over when the other ones get flat .











this is only a joke

Answer 7

There are always currents and air pressure to affect the sails.

Answer 8

The blades are razor sharp, the slightest breeze turns the blades. It took me two semesters of mechanical engineering to understand what your asking. The simplest way to learn how is to learn how they build them.

Answer 9

When there's no wind they don't move. Honest.

Answer 10

That's the miracle of Jesus.