Wind turbines are fantastic devices for securing the future of our planet. Using natural wind to convert kinetic energy into electric power involves the burning of no limited resources, release of toxic gases into the atmosphere or environmental damage in the acquisition of electricity.
From early wooden windmills used to grind grain, wind turbines have developed into tall metallic structures that now contribute energy towards domestic power supplies. They may look relatively simple beasts but there is plenty of work that goes into creating a wind turbine.
As fairly thin structures that are exposed to plenty of wind at the top, wind turbines need to be solidly secured. Usually a tubular steel or concrete foundation is laid down for this. If the turbine is part of a wind farm then underground cables will be installed to connect to each other and the control centre. This centre monitors and controls the electricity produced.
The cylindrical steel tower can vary in height depending on where the wind turbine is being erected. Normally they will stand anywhere between 25 and 75 metres tall. The components that make up the tower are assembled onsite with it laid horizontal and its security tested. Next a crane lifts the tower up vertical and into place before all the bolts are tightened and a final stability test is carried out.
The technical part of a wind turbine, the nacelle holds all the vital machinery elements for the turbine to work. Located behind the rotor blades it houses the gearbox, generator, coupling and brake and yaw mechanism. These components will all have been manufactured and assembled offsite but are mounted onto a base frame and bolted on top of the tower.
The gearbox converts the rotor motion into the rotations per minute required by the generator, matching the slow-moving rotor with the much quicker generator. This can prove more of a strain in higher wind conditions. Certain wind turbines don’t require gearboxes as they use multi-pole ring generators instead. The yaw mechanism is what turns the turbine to face the wind direction.
Some wind turbines use aluminium blades but a lot more opt for fibreglass ones. A fibreglass-resin composite mixture is poured into a blade-shaped mould which is closed and left to dry. When dry it is cleaned, sanded down and painted.
Assembly is easier on the ground so often a few of the blades are attached to the nacelle before it is joined to the top of the tower, with the final blade bolted on when the nacelle is in place.
With all the major components in place the final safety checks are made and minor pieces installed. Lifting gear and fire extinguishing equipment as well as parts for recording the wind direction and cooling, heating and lighting protection are all left until the end.
It is a more complicated process than the early wooden windmills as much of the wind turbine is crafted offsite, but the rewards are far greater for clean energy.