Specifications

3
bearings allow the wind turbine to freely pivot
around the top of the tower so that the rotor will
face into the wind.
The slip-ring assembly is the electrical connection
between the moving (as it orients with the wind
direction) wind turbine and the fixed tower wiring.
The slip-rings and yaw bearings are located just
above the tower mount. The tower mount attach-
es the XL.1 turbine to the top of the tower.
D. Tail Assembly and AutoFurl

Operation
The tail assembly, composed of a tail boom and
the tail fin, keeps the powerhead (and, therefore,
the rotor) aligned into the wind at wind speeds
below approximately 12.5 m/s (28 mph). At about
12.5 m/s the AutoFurl

action (see Figure 4) turns
the rotor away from the wind to limit its speed.
The tail appears to fold, but in reality the tail stays
stationary, as the powerhead turns sideways to
the wind. The rotor does not, however, furl com-
pletely sideways. This allows the turbine to con-
tinue to produce power in high winds. When the
high winds subside the AutoFurl

system auto-
matically restores the turbine to the normal
straight position.
E. PowerCenter
The PowerCenter, shown in Figure 3, serves as
the central connection point for the electrical com-
ponents in the system and it provides a number of
necessary and valuable control functions. Not all
of the available functions will be used in all instal-
lations. The PowerCenter also provides status
lights for the system and a handy light-bar “fuel
gage” for the battery bank.
Note
The XL.1 wind turbine will not perform
properly, particularly at low wind
speeds, without the PowerCenter con-
troller. The Power Boost circuitry in the
PowerCenter is needed to provide ac-
ceptable performance in wind speeds
below approximately 7.5 m/s (17 mph).
Figure 3, PowerCenter for the BWC XL.1
5. SYSTEM OPERATION
A. Normal Operation
The rotor of the BWC XL.1 should begin to rotate
when the wind speed reaches approximately 3
m/s (7 mph). (For the first several weeks of oper-
ation, however, the start-up wind speed will be
higher because the bearing seals have not worn-
in.) Battery charging should commence shortly
after the rotor spins up to speed. Once turning,
the rotor will continue to turn in lower wind
speeds, down to approximately 2.5 m/s (6 mph).
Note
All operational wind speeds given as-
sume steady winds, sea-level altitude
and moderate temperatures. Hot
weather, high altitude, turbulence, and
gusting winds will reduce system per-
formance.
The rotor speed will increase with increasing wind
speed and the system will provide a higher output.
This output increases rapidly because the energy
available in the wind varies as the third power
(cube) of the wind speed. For example, if the