Is
Solar Panel Tracking Cost Effective?
The gain is also dependent on latitude. At increased
latitudes the sun's arc across the sky in summer is also
increased but in winter it is decreased. The following
table shows the daylight hours (between sunrise and
sunset)
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Solar energy usually has its greatest strength in
the middle of the day and often the greatest cloud cover is in the
mornings and evenings. The energy from the sun has to penetrate through
the greatest depth of atmosphere at the horizon.
Your immediate environment and your geographic
location may play a major role in the hours of direct
sunlight (without shading) that your panels may receive. Nearby mountains,
hills, trees, tall buildings etc may considerably reduce the number
of hours of direct sunshine that your panels receive.
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Shadow throwing objects tend to have their greatest effect on a solar
panel site when the sun is lowest in the sky.
Even the smallest amount of shading reduces panel output significantly.
By referring to the table on page 114 you may get an idea of the advantage
in tracking the sun for your area by using the figures for a location
of similar latitude and similar weather conditions to yours. You simply
compare the columns labelled Sun Tracking gainst the columns labelled
Best Average Performance.
After having determined how much gain you could expect in mid summer
and mid winter you may find that you get the most benefit when you least
need it. An automatic solar tracking system usually costs more than
a 75W solar panel. Unless your loads are predominantly summer loads
(eg fridge, freezer, space cooling, pumping) and you already have at
least 8 solar panels, you may be better off with another solar panel.
An extra solar panel gives greater benefit in mid winter when there
is the greatest demand for night time lighting and entertainment. If
you need more power in winter for
lighting and entertainment because of the shorter daylight hours then
an extra solar panel may be money better spent than having a tracking
device.
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