For centuries, humans have utilized wind energy through traditional windmills. The Netherlands has played a prominent role in the development of this sector, due to its geographic conditions. It has claimed significant portions of land through a complex water management system, driven by windmill power.
The traditional windmill has for long kept its original concept, with a horizontal shaft connected to the wind vanes, which in turn was connected to a vertical shaft through a right angle transmission. This rotating shaft was utilized for the particular purpose of the windmill.
It was only towards the end of the 1970s and early 80s that the windmill was seriously developed into modern turbines for generating electricity. Various test parks were built and it became a serious alternative method to generate electricity. The first significant wind turbines had a capacity of 100 kW, with steel wind blades.
Since the early 90s, the developments in wind technology accelerated. Computer systems were incorporated to optimize the utilization and efficiency of the turbines. The capacity increased significantly with new, larger mills and better materials. Also the safety was drastically improved by using stronger, but also lighter materials.
In addition, the knowledge and insight in wind streams and climatological circumstances further advanced, allowing the modern wind turbines to better anticipate the rapidly changing circumstances during showers, storms and other turbulent situations. The wind turbines were also equipped with lightning conduction and (if necessary) heating systems to prevent icing on the blades.
Meanwhile, the scale of the turbines continued to grow. Whereas the capacity of the largest wind turbine in 1990 had a capacity of 225 kW, today's turbines can produce up to 6 MW each. The diameter of the rotor increased from 27 to 112 meters, and the shaft height (hub height) from 30 to 125 meters.
The latest models are equipped with sensors to determine undesired vibrations and allow the computer controlling system to take preventive measures. These sensors also make it possible to control the rotors individually, adjusting the angle of each blade independently during every rotation. This improves the efficiency, since the wind conditions for the blade in upright position differs from the ones below.
