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Turbine Designs Blade Material
Wind Turbine Blades
There
are several different material used for wind turbine
blades. We will skim over the materials most commonly used.
| Aluminum
Wood
Fiberglass
Carbon Fiber
|
Aluminum
Aluminum is not a suitable material for such conditions. It is
light
weight but cannot stand up to fatigue caused by repeated bending.
Wood
Wood has been used for some time in wind machines and is still
a good
material for small applications. It is relatively inexpensive and does
not take extraordinary tools to machine. This currently makes it the
material of choice for homebuilt wind turbines.
Moisture is a
problem for wood. Wood blades can be sealed with various finishes,
however, nicks and scratches in the surface coating will allow moisture
to penetrate the wood. The blades will retain moisture at differing
rates and causes blade imbalance.
Fiberglass
Fiberglass is another suitable material used in blade
construction.
Different variations in the matrix can be used such as vinyl ester,
polyester and epoxy. Fiberglass is reasonably stiff with good strength.
The Bergey XL.1 blades are made of pultruded fiberglass.
Polypropylene
Polypropylene blades are widely used by larger companies such as
Southwest
Wind Power
and Proven Energy. SWWP list their's as Polypro/Carbon glass
reinforced.
Proven blades are shown as polypropylene composite. The carbon and the
glass fibers are for reinforcement to provide a stiff blade with good
fatigue levels.
Bottom Line
The bottom line on blade material is a tough one to use as
selection
criteria. The more important issue in the blade department is the rotor
diameter or swept area.
