PacWind SeaHawk Owner's Manual - 5. System Operation
Head Allen wrench, tighten one bolt until the split-ring washer is flat. Then tighten the bolt on the
opposite side of the cage. Repeat the sequence with the next bolt over until all eight bolts are
tight. This completes the VAWT assembly.
W
The output wiring of the SeaHawk presents a low voltage shock hazard whenever the rotor
is turning at significant speeds. Caution must be exercised at all times to avoid electrical
shock.
5. SYSTEM OPERATION
A. Normal Operation
The rotor of the SeaHawk should begin to rotate when the wind speed reaches approximately 1.8
m/s 4 mph. Battery charging will commence on a 12 Volt battery system at about 3.1 m/s (7 mph),
on a 24 Volt battery system at about 5.4 m/s (12 mph) and on a 48 Volt battery system at about
10.8 m/s (24 mph).
Note
All operational wind speeds given assume steady winds, sea-level altitude and moderate
temperatures. Hot weather, high altitude, turbulence, and gusting winds will reduce system
performance. 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 wind speed doubles from 5
m/s (11.2 mph) to 10 m/s (22.4 m/s), the energy in the wind increases by a factor of eight (2
3
= 2
x 2 x 2 = 8). One result of this relationship is that there is very little energy available in light winds.
For the average site, winds in the range of 5.5 – 9 m/s (12 – 20 mph) will provide most of the
system’s annual energy production.
B. High Winds
The SeaHawk VAWT performs extremely well under high wind conditions. Since there is no need
to protect itself as do propeller based systems, the SeaHawk simply cannot spin any faster at
above about 42.75 m/s (95 mph). The SeaHawk just appears as wind loading at that point and
the wind simply goes around the SeaHawk as it is putting out full power. The SeaHawk puts out
maximum power at about 27 m/s (60 mph).
Caution
Do not install the SeaHawk wind turbine near cliffs or precipices or on sharp hills such
that the wind does not travel horizontally through the rotor.