Why wind turbine blades are gigantic
Turbine blades produced today are often 100+ meters long. Why?
You’ve seen images of huge wind turbine blades being moved across the country. They can be 100+ meters long and require specialized trucks and machinery to move them. These gigantic blades are complicated to manufacture and even harder to move. So why are they so damn big? There are two main reasons.
Longer blades cover a much larger area
The output of a wind turbine depends on the area its blades cover. A turbine with 100m blades sweeps 10,000 square meters, while one with 50m blades covers only 2,500. Over time, turbines have grown to use longer blades as power output scales up directly with area covered.
Wind is faster and more consistent higher up
Taller turbines intersect the wind at higher elevation. Longer blades necessitate taller towers, moving the wind they intersect from low elevations where it is inconsistent and slow to higher elevations where the wind is faster and more dependable.
On top of that, the power output of a turbine depends on the square of the wind speed – so a turbine tall enough to capture 10mph winds generates 4 times as much power as one closer to the ground with wind speeds around 5mph.
Putting it all together
A small increase in blade length leads to a much higher output per turbine – driven by more area covered and faster wind speeds intersected. Looking to the future, we can expect to see wind turbines far larger than those we have today.
