The Engineer's Place for News and Discussion®

 Previous in Forum: Gravitational Vortex Power Demo Next in Forum: Bicycle Generator

### Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

### Rating Vote:

Anonymous Poster #1

### Wind Power

08/06/2012 8:53 AM

Hello,

I just need to know please details concerning the following:

- In the wind turbine, the maximum electrical power (kW) delivered correponds to a certain wind speed (m/s). Why does the power decrease at a certain point even if the wind speed is still increasing?

- How to generate an average Wind Speed (in m/s) based on a graph showing the wind speed as function of the time?

Thank you!

Interested in this topic? By joining CR4 you can "subscribe" to

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru

Join Date: May 2009
Location: Ketchikan, AK, USA
Posts: 12938
#1

### Re: Wind Power

08/06/2012 9:50 PM

At high wind velocities, the turbine may need to be "furled" or otherwise limited to prevent damage.

For average wind speed, take the area under the curve and divide by the width (i.e., time).

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Guru

Join Date: May 2007
Location: NYC metropolitan area.
Posts: 821
#2

### Re: Wind Power

08/06/2012 11:17 PM

A wind turbine is a large rotating device, as such it has finite material strength limits which if exceeded, will cause its rapid destruction. All properly engineered wind turbines,regardless of their design, type, or orientation must have some mechanism for limiting its maximum speed, when that speed is reached the power output will, as you observed, will also be limited even though the wind speed is increasing.

Here's what happens if a turbine overspeeds:

Determining the wind energy potential for any site can be a daunting effort. There are many variables that can effect it, and they can vary widely from year to year. There are websites that attempt to do this based upon historical meteorological data, but the most accurate is your own study using one of those readily available personal computer based weather stations.

__________________
Curious minds want to know, engineering minds get answers....
Commentator

Join Date: Feb 2007
Location: Gdansk, Poland
Posts: 97
#3

### Re: Wind Power

11/16/2012 2:46 PM

Power generated by wind turbine is (roughly) proportional to the 3-rd power of wind speed. So usual avg wind speed is not a good measure of energy of the wind.

If You have v(t), and Power versus wind speed, P(v) curve of Your turbine, You can calculate energy production during observed time v(t).

Energy generated = integral(Power(v(t)dt)

This is more exact evaluation of expected energy production, than using avg speed and Annual energy =f(avd speed), (another curve characterising turbine, usually suppiled by turbine maker). However v(t) should be collected at least for 2 years prior to serious investment. Finally compare Your avg speed at observed time with avg speed at nearest meteorology stations at the same time. And coorect Your results on the basis of 25 ..50 years observations at that stations.

Interested in this topic? By joining CR4 you can "subscribe" to

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!

czgut (1); RAMConsult (1); Tornado (1)

 Previous in Forum: Gravitational Vortex Power Demo Next in Forum: Bicycle Generator