Windmills represent one of the key pieces of technology that enabled our ancestors to transform the power of the wind into a physical force that can be used for countless things, from most traditional jobs such as grinding grains and moving water to the many more industrial and agricultural needs.
In this article, we discuss What are windmills, the history of windmills and how they evolved into modern designs, as well as how they work.
What is Windmill?
A windmill is a structure that converts wind power into rotational energy by means of vanes called sails or blades, specifically to mill grain (gristmills), but the term is also extended to windpumps, wind turbines, and other applications. The term wind engine is sometimes used to describe such devices.
A windmill is a device for tapping the energy of the wind by means of sails mounted on a rotating shaft. The sails are mounted at an angle or are given a slight twist so that the force of the wind against them is divided into two components, one of which, in the plane of the sails, imparts rotation.
Like waterwheels, windmills were among the original prime movers that replaced human beings as a source of power.
Windmills were used throughout the high medieval and early modern periods; the horizontal or panemone windmill first appeared in Greater Iran during the 9th century and the vertical windmill in northwestern Europe in the 12th century. Regarded as an icon of Dutch culture, there are approximately 1,000 windmills in the Netherlands today.
Modern windmills as we know them today started first appearing around the 8th and 9th centuries in the middle east and Western Asia.
Wind turbines started being made as far back as 1887, and after the 1900s more and more wind pump windmills gained the ability to generate electricity as their secondary job.
People used wind energy to propel boats along the Nile River as early as 5,000 BC. By 200 BC, simple wind-powered water pumps were used in China, and windmills with woven-reed blades were grinding grain in Persia and the Middle East.
New ways to use wind energy eventually spread around the world. By the 11th century, people in the Middle East were using wind pumps and windmills extensively for food production. Merchants and the Crusaders brought wind technology to Europe.
The Dutch developed large windpumps to drain lakes and marshes in the Rhine River Delta. Immigrants from Europe eventually took wind energy technology to the Western Hemisphere.
American colonists used windmills to grind grain, pump water and cut wood at sawmills. Homesteaders and ranchers installed thousands of windpumps as they settled in the western United States. In the late 1800s and early 1900s, small wind-electric generators (wind turbines) were also widely used.
The number of wind pumps and wind turbines declined as rural electrification programs in the 1930s extended power lines to most farms and ranches across the country.
However, some ranches still use wind pumps to supply water for livestock. Small wind turbines are becoming more common again, mainly to supply electricity in remote and rural areas.
Types Of Windmills
There are two main types of windmills: horizontal-axis wind turbines and vertical-axis wind turbines.
1. Vertical-Axis Turbines
In the early development stage, vertical-axis windmills were very popular and were in wide use. It is in such a design that the blades will be perpendicular to the ground.
These vertical-axis windmills replace by horizontal-axis windmills later due to their incompetence. It was mainly used for grinding grains or pumping water.
2. Horizontal-Axis Turbines
The Horizontal axis windmills won many hearts due to their efficiency and productivity. It is known for its elasticity design as it harnesses more wind and easy for the operating person to change the direction according to the wind flow.
For more information check out our article: What is a Wind turbine and how does it work?
3. Post Mill
The post mill is a windmill supported by a post on which it pivots to catch the wind. It is the earliest type of European windmill. Its defining feature is that the whole body of the mill that houses the machinery is mounted on a single vertical post, around which it can be turned to bring the sails into the wind.
Post-mills dominated the scene in Europe until the 19th century when tower mills began to replace them
Types of a post mill
There are many types of post mills.
- Sunk post mill
- Open trestle post mill
- Post mill with a roundhouse
- Hollow post mill
- Composite post mill
- Paltrok post mill
4. Smock Mill
The smock mill is a type of windmill that consists of a sloping, horizontally weathered, thatched, or flaky tower, usually six or eight sides. It is topped with a roof or cap that rotates to bring the sails into the wind.
The smock mill is made of wood and often sits on a brick base. It differs from a post mill in that the body does not rotate, like a tower mill, it is the cap that rotates to face the wind.
5. Tower Mill
A tower mill is a type of vertical windmill consisting of a brick or stone tower on which a wooden “cap” or roof sits, on which only the cap rotates to allow the sails to look into the wind.
Tower Mill is a cotton mill in Dukinfield, Greater Manchester, England. It is a listed building.
It was designed by Potts, Pickup & Dixon in 1885 and spun cotton using mules and spinning frames until ceased to be used as a cotton mill in 1955 and then used by various industries and broken down into small units according to one-point plans.
It even became decided to convert the mill into luxury apartments, but with the 2007/08 recession, this plan was abandoned.
6. Fan mill
Generally, Fan mills are single-use small windmill designs. It has four to twenty blades and is mainly used to pump water.
Uses of windmill
- Windmills are mechanical devices that use wind turbines for converting wind energy into electrical energy.
- Windmills have been used for pumping groundwater or grinding grain.
- Extraction of oil from the seeds.
- Milling of the grains.
- Processing of commodities like Tobacco, Cocoa, Dyes, Spices Paints, and Stock-watering.
Facts about Windmill
There are some interesting facts about windmills. We hope you will enjoy them.
- Wind energy was first developed with windmills in 200 BC in Persia and China.
- Wind energy was then used for hundreds of years to pump water and crush grain.
- The first modern turbine was built in Vermont in the 1940s.
- Turbine towers normally stand over 328 ft tall.
- 20% of the energy used in Portugal and Denmark comes from windmills
- China has the most wind turbines
- Every second Saturday in May is celebrated as ‘National Mills Day’ in Holland
- One megawatt of wind power can save about 2600 tons of carbon dioxide produced by fossil fuel-powered energy sources oldest windmill dates back to the eighth century and was in the Netherlands.
Windmills work on a simple principle: instead of using electricity to make wind—like a fan—wind turbines use wind to make electricity. Wind turns the propeller-like blades of a turbine around a rotor, which spins a generator, which creates electricity.
The terms “wind energy” and “wind power” both describe the process by which the wind is used to generate mechanical power or electricity. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity.
Wind turbines can turn the power of wind into the electricity we all use to power our homes and businesses. They can be stand-alone, supplying just one or a very small number of homes or businesses, or they can be clustered to form part of a wind farm.
$1,300,000 USD per megawatt. The typical wind turbine is 2-3 MW in power, so most turbines cost in the $2-4 million dollar range. Operation and maintenance runs an additional $42,000-$48,000 per year according to research on wind turbine operational cost.
The towers on most commercial wind turbines are in the range of 200-260 feet tall. The blades, often well over 100 feet long, when counted in total height push the number well into the 300s. The Gamesa G87 model wind turbine’s blades reach a height of 399ft.