How does wind energy work? I know a little, but does anyone have a clearer idea?

6 Responses to “How does wind energy work? I know a little, but does anyone have a clearer idea?”

1. Jon on October 29th, 2009 7:23 pm

   Wind spins turbines which powers a generator. That’s the easy way to explain it. But if you want to know more in detail:

   "Wind power is the conversion of wind energy into a useful form, such as electricity, using wind turbines. At the end of 2007, worldwide capacity of wind-powered generators was 94.1 gigawatts.[1] Although wind currently produces about 1% of world-wide electricity use,[2] it accounts for approximately 19% of electricity production in Denmark, 9% in Spain and Portugal, and 6% in Germany and the Republic of Ireland (2007 data). Globally, wind power generation increased more than fivefold between 2000 and 2007.[1]

   Most wind power is generated in the form of electricity. Large scale wind farms are connected to electrical grids. Individual turbines can provide electricity to isolated locations. In windmills, wind energy is used directly as mechanical energy for pumping water or grinding grain.

   Wind energy is plentiful, renewable, widely distributed, clean, and reduces greenhouse gas emissions when it displaces fossil-fuel-derived electricity. The intermittency of wind seldom creates problems when using wind power to supply a low proportion of total demand. Where wind is to be used for a moderate fraction of demand, additional costs for compensation of intermittency are considered to be modest.[3]"

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

   Hope that helps you.
   References :

2. Dani on October 29th, 2009 7:59 pm

   The wind blows
   A thingy spins
   it makes energy.
   
   References :

3. johnnydangerously59 on October 29th, 2009 8:23 pm

   A wind turbine is just an electric motor in reverse. If you take a fan and spin the blades fast without it plugged in, it will generate electricity. A motor is just magnets and windings and when you pass them over each other they create electricity. If you put electricity in, it creates movement. That’s why electric motors work.

   You can use that same type of system to create energy from water but instead of a fan, you use a paddle wheel to turn the motor and create electricity. I made one out of an old car alternator, some floats and sheet metal and I was able to power several lights for a campsite for free. I just anchored it in the river and harnessed the free energy. I also used that same energy to cook with and to charge up batteries while I was camping. It’s quite easy to do.
   References :

4. xyzpdqfoo on October 29th, 2009 8:34 pm

   If you move a magnet through a loop of wire, you generate electricity. On a basic level, that’s what a wind generator does. The wind blows on a propeller and makes the propeller move. Inside the generator are loops of wire and magnets attached to the propeller, and when the propeller moves it makes the magnets move through the wire, and it generates electricity. Simple.
   References :

5. F1SH_0N on October 29th, 2009 9:20 pm

   The Mechanics of Wind Turbines

   Modern electric wind turbines come in a few different styles and many different sizes, depending on their use. The most common style, large or small, is the "horizontal axis design" (with the axis of the blades horizontal to the ground). On this turbine, two or three blades spin upwind of the tower that it sits on.

   Small wind turbines are generally used for providing power off the grid, ranging from very small, 250-watt turbines designed for charging up batteries on a sailboat, to 50-kilowatt turbines that power dairy farms and remote villages. Like old farm windmills, these small wind turbines have tail fans that keep them oriented into the wind.

   Large wind turbines, most often used by utilities to provide power to a grid, range from 250 kilowatts up to the enormous 3.5 to 5 MW machines that are being used offshore. Today, the average land-based wind turbines have a capacity of 1.5 MW.[7] Large turbines sit on towers that can be anywhere from 50 to 100 meters tall, and have blades that range from 30 to 50 meters long.[8] Utility-scale turbines are usually placed in groups or rows to take advantage of prime windy spots. Wind "farms" like these can consist of a few or hundreds of turbines, providing enough power for tens of thousands of homes.

   From the outside, horizontal axis wind turbines consist of three big parts: the tower, the blades, and a box behind the blades, called the nacelle. Inside the nacelle is where most of the action takes place, where motion is turned into electricity. Large turbines don’t have tail fans; instead they have hydraulic controls that orient the blades into the wind.

   In the most typical design, the blades are attached to an axle that runs into a gearbox. The gearbox, or transmission, steps up the speed of the rotation, from about 50 rpm up to 1,800 rpm. The faster spinning shaft spins inside the generator, producing AC electricity. Electricity must be produced at just the right frequency and voltage to be compatible with a utility grid. Since the wind speed varies, the speed of the generator could vary, producing fluctuations in the electricity. One solution to this problem is to have constant speed turbines, where the blades adjust, by turning slightly to the side, to slow down when wind speeds gust. Another solution is to use variable-speed turbines, where the blades and generator change speeds with the wind, and sophisticated power controls fix the fluctuations of the electrical output. A third approach is to use low-speed generators. Germany’s Enercon turbines have a direct drive that skips the step-up gearbox.

   An advantage that variable-speed turbines have over constant-speed turbines is that they can operate in a wider range of wind speeds. All turbines have upper and lower limits to the wind speed they can handle: if the wind is too slow, there’s not enough power to turn the blades; if it’s too fast, there’s the danger of damage to the equipment. The "cut in" and "cut out" speeds of turbines can affect the amount of time the turbines operate and thus their power output.

   There is a great picture on the web site, plus all sorts of other good information.

   References :
   http://www.ucsusa.org/clean_energy/renewable_energy_basics/how-wind-energy-works.html#The_Mechanics_of_Wind_Turbines

6. gribbling on October 29th, 2009 9:37 pm

   Almost *all* forms of electricity generation involve "it turns the blades and generates electricity".

   When fossil fuels are burnt, they heat water up to steam – and this high-pressure steam turns the vanes of a turbine, and thereby generates electricity.
   When nuclear power is used – it does the same thing (boils water, generates high-pressure steam, turns turbines).
   Even hydroelectric dams use this – except it is water flowing downhill which turns the turbines, not steam.

   Basically, the turbines themselves are what you need to read up on. They are sort of electric motors in reverse.
   When you pass an electric current through a wire in a magnetic field, it generates kinetic energy at 90o to the direction of the current-flow.
   If you do it *backwards* – moving a metal wire through a magnetic field, then it generates an electric current in the wire.

   References :
   http://en.wikipedia.org/wiki/Turbine

Leave a Reply