Thread: Antenna rotator
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Old November 27th 07, 10:25 PM posted to rec.radio.amateur.antenna
Jim Lux Jim Lux is offline
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First recorded activity by RadioBanter: Mar 2007
Posts: 801
Default Antenna rotator

Highland Ham wrote:
There is a simple, elegant and more expensive means: Buy a Yaesu az/el
rotor as for satellite operation. Connect the control box through a
SASI tracker or similar device and use Nova or some other sat tracking
program. Almost all of the Keplerian element lists include the sun.

Dave Heil K8MN

Yes, but I do believe it's overkill.



Could be. I guess it depends on how precisely the sun panels need to
be pointed at the sun. Most solar panels are fixed in position, on a
house top or whatever, just to generally catch the rays.


=======================
Yes to a fixed position due SOUTH ,but it means the panels will not
receive all that much energy or very little during the post noon
daylight hours .
It is debatable how much that is and consequently whether a rotating
system would be justifiable.


One can fairly trivially calculate this, at least in terms of the
incident energy on a flat plate. Taking into account the efficiency
changes in the solar panel is a bit trickier.

As a start, consider a panel tilted so that it directly faces the sun at
noon, and to make things easy, assume we're at the equinox. The angle
varies from -90 to 0 to 90 over a span of 12 hours. So, the average
insolation is the integral of cos(theta) from -pi/2 to pi/2 divided by
pi, or, 2/pi... about 0.63... So, pointing right at the sun would pick
up about 50% over the day. (assuming you've got view from horizon to
horizon, and neglecting the loss due to atmospheric attenuation, which
is significant)

Depending on what you consider as your energy costs, you can decide if
it's worth it. A typical solar panel installation runs about $6-7/watt,
so the improvement due to tracking would let you install a 35% smaller
installation, for the same output, equivalent to paying only $4-5/watt.
On a 1kW system, this is several thousand dollars, which might
actually get close to the cost of the actuators.

There IS a reliability and maintenance costs issue to consider though..


However to find out and possibly advise
people ,after this test, how much more energy can be trapped ,I feel
setting up a rotating solar panel system is a worthwhile effort.
As an alternative to K8MN's suggestion a low cost (modified)satTV
tracking system might prove suitable.

Frank GM0CSZ / KN6WH