Have you ever heard of “wind power” or “wind energy”? As the term implies, wind energy or power is when electricity is created by the wind (air flows), the kind that is naturally created in the earth’s atmosphere.
If you’ve ever taken a long road trip or taken a cross-country road trip, you’ve probably seen what can be described as rows and rows of massive windmills out in the middle of nowhere. Those machines are actually called “turbines,” which Collins Dictionary defines as “...a machine or engine which uses a stream of air, gas, water, or steam to turn a wheel and produce power.”
According to the American Wind Association (AWEA), “Modern wind turbines are used to capture kinetic [relating to motion] energy from the wind and generate electricity.”
How Do Turbines Work?
So, how do wind turbines work? As the wind blows past a wind turbine, the wind’s kinetic energy is captured by the blades, rotating them and turning the wind into mechanical energy. As the blades rotate, they turn an internal shaft that is connected to a gearbox, in effect increasing the rotation speed by a factor of 100, according to the AWEA. This process spins a generator, which then produces electricity.
Generally, modern turbines generate electricity once wind speeds are between six and nine miles per hour (mph) – this is called “cut-in speed.” If the wind is blowing too hard, for example, around 55 mph, the turbines will automatically shut down to protect the equipment from sustaining damage.
“Another common measure of wind energy production is called capacity factor. This measures the amount of electricity a wind turbine produces in a given time period (typically a year) relative to its maximum potential,” according to the AWEA.
Windmills vs. Wind Turbines
We used the word “windmill” earlier to describe wind turbines, but they’re not the same thing and that’s a common misconception. Windmills generate mechanical energy to grind grain and pump water, but they don’t generate electricity. On the other hand, wind turbines do; they capture the wind’s kinetic energy and convert it to kinetic energy.
If you’ve ever seen a bunch of wind turbines built close together, what you’re witnessing is called a wind farm or a wind project, which acts as a power plant, sending the electricity to the grid.