400 Watt VAWT

This wind turbine is a small, 400-Watt Vertical Axis Wind Turbine (VAWT).

The turbine rotor is 24 inches in diameter and the blades are 48 inches long, giving the turbine an 8-ft² (0.75 m²) wind swept area. It develops 670 Watts at 15.5 m/s (35 mph) wind speed and 433 Watts at 13.4 m/s (30 mph), achieving a 40% coefficient of performance (C_P).

The generator is a direct-drive, rare earth, permanent magnet (NdFeB), 3-phase power supply. It contains 36 pairs of rare earth magnets with 27 coils arranged 9 coils per phase.

The generator has low internal impedance, minimizing the "dragging down" of the power under load.

See a video of the turbine in action.

Benefits

Starts and operates at wind speeds of less than 2 m/s (4.4 mph). This gives the turbine a very high capacity factor (C_F) over the average annual wind velocities of the site.
The relatively high solidity of the turbine makes the face of the rotating blades appear to be solid, preventing birds from flying into it - birds are not harmed.
It obtains useful torques in low winds, enabling the turbine to extract energy from the wind at a high percentage of the time.
It obtains high values of C_P, maximizing the amount of energy to be taken from the wind at any velocity.
Where fixed-pitched VAWTs of the Darrieus type have problems self-starting, our turbine has no "dead band" of TSR and self-starts.
Because of the high capacity factor, the problem of storage of power during low-demand would be reduced. It is able to provide power when the power is needed for a higher percentage of the time. This allows us to consider this turbine for grid-metered operation.

Contact us for more information about this concept.

REM Enterprises, Inc.
4804 NW Bethany Blvd., SuiteI2#191
Portland, OR 97229-9260
info@remnet.com
Copyright 2006 PacWind