The Engineering design team of Jonny Draleau, Chad Fritz, and
John Wells are nearing completion of their senior project in the
Electrical Engineering and Electronics department of Norwich Tech.
They have designed and built a Solar Panel assembly that tracks
the sun.
Photo-Voltaic Solar Panels convert the suns light directly to
electricity. They power satellites, the space station, remote cabins,
and provide supplemental power to many homes and businesses. As
the supply of fossil fuels begin to run out and become increasingly
more costly, solar panels are becoming an important energy source
for the future, especially as the technology improves and they
come down in cost and increase in efficiency. They are totally
non-polluting and emit no greenhouse gas so they are very environmentally
friendly. They produce their maximum power only when they are pointed
directly at the sun however. By mounting the solar panel in a movable
platform and providing a mechanism that causes the panel to follow
the sun’s movement as it rises in the east, climbs and falls
in the sky, and sets in the west, the power output of the
panel can be increased by about 20% over the same size panel in
a fixed installation.
The Norwich Tech engineering team has designed such a system.
The design was not from a book or magazine but came from many hours
of brainstorming and trial and error. The design has evolved considerably
from the first sketches made in September. The final version consists
of a wooden platform that has an electric motor mounted underneath
it. The motor shaft turns a small gear on the top of the platform
which turns a much larger gear to get considerable mechanical advantage.
This large gear is the rotating platform in which a pair of upright
metal posts is welded. A 45 watt solar panel is mounted in a metal
frame that swings freely between the two uprights. The rotating
gear allows the panel to track the east-west movement of the sun.
The swing bearings between the uprights allow the panel’s
tilt to be adjusted for the rising and setting movement of the
sun. The tilt is controlled by a second motor mounted on an upright,
set up as winch. The panel is held back by two powerful springs
which provide tension. A steel cable attached at a corner of the
panel is pulled in or out by the winch motor to control the up-down
tilt of the panel.
An electronic sensor assembly, consisting of an array of CDS photocells
and ‘shadow vanes’, is mounted at the top of the panel
in a transparent, waterproof, box. This sensor array senses the
position of the sun and sends signals to an electronic circuit
that processes the data and converts it to commands that go to
two motor controllers. The controllers activate the motors that
rotate and tilt that panel keeping it always pointing directly
at the sun. The Solar Panel charges a 12 volt battery. An Inverter
converts the 12 volt battery power to 120 volt AC household current.
The team has overcome many problems and setbacks during the design
and construction of this sophisticated engineering project. They
have come up with creative solutions to difficult problem and have
experienced the satisfaction of seeing an idea turn into something
real. They also learned a bit about engineering along the way.
Special thanks goes out to the carpentry department for building
the platform, to the Auto department for supplying some of our
gears and mechanical parts, and a very special thanks to plumbing,
especially Joe Campbell, for doing our welding.
