Windmill vs. Wind Turbine: Things You Didn’t Know Before

Windmills and wind turbines are the most common technologies used to harvest electricity from wind and put it into practical use. Wind plays a great role in energy supply around the world. Its use can be traced to centuries ago when it was used to sail boats in lakes and rivers. Wind technology has been reinvented and developed many times throughout history.

There is a common misconception that windmills and wind turbines are the same thing, but the truth couldn’t be further. They have different operating principles and in this post, we take a closer look at both to tell what you don’t know about windmills and turbines.

What is a Wind Turbine?

Turbines harness electricity from the kinetic energy found in wind. Traditionally, they generated mechanical energy. The technology has advanced considerably over the years, and turbines are now used to generate large quantities of electricity.

There are 2 main types of wind turbines i.e. horizontal axis and vertical axis. Turbines have blades and a steel tower. The blades are usually made from fiber glass and reinforced with materials like wood polyester and epoxy. Wind turbines also come in various sizes, a factor that plays a crucial role in the amount of electricity that can be produced.

What is a Windmill?

These also use kinetic energy in wind to generate mechanical or electric energy. Windmills were one of the first man-made means of producing power. They were used to saw-mill timber, pump water, grind grain and more on farms. Windmills have a spinning shaft that turns a camshaft, which is connected to the machinery by rods and gears. The energy produced goes directly into the work.

Differences Between Windmills and Wind Turbines:

Working mechanism

Turbines have a simple working principle. They have 2-3 large propeller blades that spin around a rotor when the wind blows. The rotor is connected to the main shaft. When the wind blows, the blades spin and drive an electrical generator that in turn generates electricity.

Windmills feature large blades that move in circular motions when the wind blows. This in turn spins the shaft that prompts the generator to produce electricity. The generator is connected to the blades. 


The term windmill refers to a wind-powered device that is capable of converting wind energy to mechanical power. It is primarily used to grind grain, pump water and other chores around the farm. It harnesses mechanical energy directly from kinetic energy in wind. This is achieved using vanes more commonly known as blades and sails.

Turbines are mechanical devices that use kinetic energy in wind to generate electricity. They produce far more electricity than windmills, with some of the largest models powering more than 600 households. Smaller turbines can meet the energy needs of 1-3 households. Turbine technology is very cost effective and despite the ability to generate large amounts of electricity, doesn’t produce greenhouse gases.

Applications of turbines and windmills

The rotational energy generated by windmills is mainly used for pumping water and grinding grain like wheat to flour. These devices work efficiently in extreme temperatures and bad environmental conditions. This is one of the factors that make them a great investment.

Windmills are also used for other applications like shredding agricultural material and rocks. Turbines are used to produce electricity for individual or business use. Some energy service companies harvest electricity using turbines for distribution to homes, businesses, and schools. Some municipalities and local governments also benefit from commercial scale wind power.

Operating principle

The blades of wind turbine take advantage of the aerodynamic forces generated when the wind hits the blades. This coupled with the curved shape of the blades causes the blade to generate lift, much like the wings of an airplane. Low pressure is generated on the side when wind passes over the aero foil. This pushes the high pressure to the side of the aero foil. On the other hand, pressure difference in the case of windmills is created over different parts and causes the blades to rotate.

Side by Side Comparison:


Wind Turbines

Convert kinetic energy in wind to mechanical energy

Converts wind energy to larger amounts of electricity

Mainly used for pumping water and grinding grains

Commercially used to meet energy needs of up to 600+ homes, schools or businesses

Uses vanes called blades or sails to generate mechanical energy

Low-cost and effective source of energy that uses blades to produce electricity

Pressure difference is created when wind blows, causing the blades to rotate

Blades operate on the principle of lift and drag, just like airplane wings

Bottom Line

Wind energy is one of the most reliable and cost effective sources of renewable energy. It plays a significant role in the world’s energy supply. Wind turbines and windmills are technologies used to harvest electricity from the wind, but they are different in a lot of ways. While people have a tendency to use the words interchangeably, their operating and working principles are very different.

Windmills use vanes to convert kinetic energy to mechanical energy while wind turbines generate large amounts of electricity. The latter can meet the energy needs of hundreds of homes.

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