HBM gets close to the wind
With increased focus on increasing the amount of power supplied from renewable
energy sources, the use of wind farms has grown steadily over the last
few years. For obvious reasons the wind turbines operate in extremely
windy, often stormy, areas, so high demands are made on the structure
and material of the blades which must be able to withstand the peak loads
that happen during strong gusts. Current designs are usually based on
three blades forming a rotor of around 60 metres in diameter to drive
the wind turbines. However, HBM is working with NEG Micon Rotors at its
UK research and development centre to develop the next generation of rotor
blades which will convert wind energy into electricity more efficiently.
These blades are 40m long for rotors of up to 80m in diameter and have
an output of 1.5MW per turbine. The blades are made of wood, glass fibre
and resin, as NEG believe this construction gives much improved strength,
performance and lightness over other blades.
The blades are tested for static and fatigue loads to ensure safety and optimum performance. A number of variables, such as changes in ambient temperature and humidity, can affect the performance of a blade and these need to be taken into account in the tests. HBM’s data acquisition and analysis equipment enables simultaneous measurement from up to 100 sensors located on the blades. Blade designs are also tested to destruction and the point at which the blade material fails carefully analysed to ensure the design meets or exceeds the specified design criteria.