Wind turbines – major investment in the energy field

Wind turbines can be found in a range of sizes. They are of horizontal and vertical axes. Normally small wind turbines are installed to operate tasks such as battery charging and sailing boats while large wind turbines with arrays of grids are used for commercial electrical purposes. Horizontal wind turbines have been the most commonly used for many years. It comprises of a gear box, rotor shaft and brake accessories and are normally installed on a towers. These are mostly fixed with computerized sensors and servomotors to maximize rotations of the blades thus enabling them to produce more electricity.

Wind turbines installed in wind farms produce electricity for commercial purposes. These mostly have three blades pointed into the wind direction by computerized sensors. The speed of the rotation is about 320Km per hour. Although the rotation speed is high, most modern wind turbines are installed in such a way to reduce torque ripples as much as possible. The blades are painted mostly with the colour gray to match with the background of the sky. Length is between 20 to 40 metres. The towers after being mounted are between 60 to 90 metres in height. The rotation of the blades is at 10-22 revolutions per a minute. The gearboxes speed up the generators and some generators operate at fixed speed. Advanced safety measures are fixed to them to avoid harm from heavy storms.

The main rotor shaft of vertical-axis wind turbines is vertically fixed. They are not pointed into the wind direction. Rotational speed of this type is very low which resulted in producing high torque, noise, vibration and low power as well. The vertical axis wind turbines are kept at ground level. Unlike their tower mounted horizontal counterparts, vertical axis wind turbines can be easily maintained as they are at ground level. However, since they are near the ground, they get very low wind speed and produce low energy. On the other hand, they can be mounted on rooftops minimizing most problems they face at ground level.

There are three main components in conventional wind turbines and they are the rotor, the generator, and the structural support. The rotor costs about 20% of the entire cost of a wind turbine, which includes the blades. These blades are instrumental in converting wind energy to less speed rotational energy. The cost of the generator is about 34% of the whole cost of a wind turbine. It consists of an electrical generator, controlling items such as gearboxes, variable transmission etc. This part is instrumental in converting the rotated low speed energy to high-speed revolution, enough to produce electricity. The structural support costs about 15% of the entire cost.

Even though installation cost of the wind turbine is considerably high, it can cut the electricity bills to a great extent on the long-term basis. Although many researches and new inventions of wind turbines are frequent occurrences, it is doubtful whether wind turbines will be able to provide at least 45 percent of the present World's electricity needs. However, the wind power technologies have developed and the benefits gained from wind power are of an appreciable level at present.