A HAWT looks simple from the road: a pole with a propeller. But inside the propeller and the box on top of the pole, there are five parts doing real work.
The Blades
The blades are the most visible part. Two or three of them, long and slender, sweeping through the sky.
They look simple but they're shaped like an airplane wing. The air flowing over them creates a pull that yanks them around in a circle. That pull is called lift, and it's the same trick that keeps a 747 in the air.
On a big offshore turbine, one blade can be longer than a soccer field. They're usually made of fibreglass or carbon fibre, the same stuff used in racing bikes and Formula 1 cars. Light, but strong enough to handle hurricane gusts.
The Generator
The generator is where the spinning becomes electricity. It sits inside the nacelle, the box at the top of the tower.
Inside the generator is a magnet and a coil of wire. When you spin the magnet inside the coil, electricity flows out the wire. Scientists call this electromagnetic induction. That's just a fancy way of saying "spin a magnet in a coil, get electricity". The trick has been around since the 1830s, and almost every electric motor and generator on Earth uses it.
The shaft from the blades runs into the generator and turns the magnet. The faster the wind blows, the faster the magnet spins, the more electricity comes out.
The Nacelle And The Tower
The nacelle is the box at the top of the tower. It holds the generator, the gearbox, the controls, and the brake. From the ground it looks small, but on a big turbine it's the size of a school bus.
The tower is the pole that holds the nacelle up high. Towers are usually made of steel or concrete. Height matters more than you'd think: every extra metre of tower height catches faster, smoother wind. That's why modern turbines keep getting taller.
The Yaw System
A HAWT has to face the wind to work. So the whole nacelle sits on a giant turntable called the yaw system.
Sensors on top of the nacelle watch which way the wind is blowing. Motors then slowly rotate the nacelle to point the blades into the wind. It's like a weathervane, but powered and precise.
Without the yaw system, a HAWT in shifting wind would just spin uselessly.
The Control System
The control system is the brain. Computers inside the nacelle watch the wind speed, the blade angle, the yaw direction, the generator output, and dozens of other things.
When wind gets too strong, the controls pitch the blades, twisting them so they catch less wind, like turning a sail flat to spill the air. If a storm hits and the rotor is in danger of spinning too fast, the brakes lock it down.
When wind is just right, the controls keep everything tuned for maximum power.
→ All the electronic parts in a wind setup
Five parts. Working together. Turning moving air into power for your kitchen.
