Asif ali

A windmill is a mill that converts the energy of wind into rotational energy by means of vanes called sails or blades. Centuries ago, windmills usually were used to mill grain, pump water, or both.

wind turbines operate on a simple principle. The energy in the wind turns two or three propeller-like blades around a rotor. The rotor is connected to the main shaft, which spins a generator to create electricity.

The purchase and installation of very small (<1 kW) off-grid turbines generally cost $4,000 to $9,000, and a 100-kW turbine can cost $350,000. The federal government and many states have rebate or tax credit programs in place to encourage investment in small wind.

What is Electricity?

Electricity is energy transported by

the motion of electrons

**We do not make electricity, we CONVERT other energy sources into electrical energy**

Conversion is the name of the game

How Does a Generator Work?

• Wind power generators convert wind energy (mechanical energy) to electrical energy.

• The generator is attached at one end to the wind turbine, which provides the mechanical energy.

• At the other end, the generator is connected to the electrical grid.

• The generator needs to have a cooling system to make sure there is no overheating.

Where do we get our electricity?

Types of Electricity Generating Windmills

Small (10 kW)•Homes•Farms•Remote Applications (e.g. water

pumping, telecom sites, icemaking)

Large (250 kW - 2+MW)

•Central Station Wind Farms

•Distributed Power

Intermediate (10-250 kW)•Village Power•Hybrid Systems•Distributed Power

Parts of a Wind Turbine

Wind Turbine Perspective

Nacelle56 tons

Tower3 sections

Workers Blade112’ long

Large Wind Turbines

• 450’ base to blade• Each blade 112’• Span greater than 747• 163+ tons total• Foundation 20+ feet deep• Rated at 1.5 – 5 megawatt• Supply at least 350 homes

Calculation of Wind Power

•Power in the wind Effect of air density,

– Effect of swept area, A– Effect of wind speed, V

R

Swept Area: A = πR2 Area of the circle swept by the rotor (m2).

Power in the Wind = ½ρAV3

Construction

Operations/Maintenance

Maintenance

Engineering/Design