Amateur wind turbines can often be as important to one as a 100-foot tall turbine with a giant propeller, because even if they’re small, they provide the energy necessary for a family’s needs, for example. Building safe and effective parts for this green technology niche is as important as building more efficient turbines at the high size.
Electric Pinwheels, a Windsor, NY-based company founded in 2008, has designed flexible and easily-attachable blades specially suited for small wind turbines. Their working principle resembles that of a bird’s feather and the overall weight is reduced by 63 percent compared to wood of fiberglass blades having the same size.
The company even demonstrates the technology through a video showing an 8-seconds install, unlike typical wind turbine blades, which have to be attached with bolts or screws, and that may require alignment or balancing.
These bolts and screws also require a specific torque to prevent loosening during operation, however properly calibrated torque wrenches are not found in the typical toolbox. Attaching blades can take a long time and may not be installed properly, leading to a dangerous out-of-balance turbine and possible catastrophic failure.
They use a special airfoil that, combined with the right type of alternator with larger magnets and coils harvests even low-speed winds. The S809 airfoil, otherwise used in many utility-scale wind turbines, has impressive aerodynamic properties over other airfoil shapes.
Lighter blades allow quicker response to changing wind speed and direction. The rotor on a wind turbine acts as a large gyroscope, resisting change in direction as it spins. Reducing the rotating mass by 63% and moving weight toward the center of rotation has the effect of reducing the moment of inertia by 78%, which is the property that governs the degree of gyroscopic effect.
Electric Pinwheels even shares a free template that you can use from their website to create your own wind turbine blade.
[via electric pinwheels]