Wind Turbine Blades

Wind power is one of the most established types of renewable energy worldwide, especially in countries like Denmark, where it accounts for 20% of the total electricity produced, followed by Ireland and Portugal with 14%. Worldwide wind power capacity is 159.2GW. Wind power is generated through wind turbines with massive blades, or domestic turbines with smaller blades.

In order to improve efficiency, wind turbine blades are getting bigger, and some of them can reach hundreds of feet. They must be very resilient in order to cope with the constant exposition to the elements. One company called Owes Corning, for example, makes wind turbine blades with epoxy resin, which it says improves aerodynamics and strength while at the same time it doesn�t have to sacrifice length. Wind turbine blades also use aluminium and composite materials to achieve low rotational inertia, that is, the turbines can accelerate quickly if the wind picks up and thus keep tip speed ratio more constant.

Another major concern when manufacturing wind turbine blades is to keep their weight under control. Domestic blades can be made from aluminium, which is a light type of metal, wood, canvas and PVC. The drawback is that these materials require constant maintenance. Besides, wood and canvas offer low aerodynamic efficiency. A better alternative is solid airfoils. The good news is that smaller blades for domestic use can be made by the user with the help of a manual.

The number of blades placed on a wind turbine varies. To determine that number designers take into account several factors such as aerodynamics efficiency, component costs, system reliability and aesthetics. In most cases a wind turbine will have two or three blades.