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4 INSTALLING THE SOLAR ARRAY
Sunlight is the “fuel” that drives a solar pump.
Full solar exposure of the solar array is critical
for full performance of a solar-direct system.
Choose a location for the solar array that has
unrestricted sun exposure through the day
and through the year. The array can be placed
several hundred feet (100 m) or more from the
wellhead. There will be no loss of perform-
ance if the electrical wire is sized properly, but
naturally, the cost of wire will increase signifi-
cantly. The System Sizing Table specifies
wire size requirements for both normal and
extended wire lengths.
CAUTION Shading a small
portion of a PV array may cause
the pump to stop completely.
Each PV module (panel) contains
a series of solar cells (typically
36 or 72 cells). Every cell that is shaded acts
like a resistor, reducing the output of the
ENTIRE ARRAY. Shading just a few cells will
reduce the power disproportionately, and may
stop the pump. Consider this when deciding
where to install the array.
To determine where shadows may be cast at
any time of the year, you can survey the site
with a Solar Pathfinder
®
. This device is
especially useful in forested areas or wher-
ever there are obstructions nearby. It is
available directly from Solar Pathfinder (USA)
tel. (317) 501-2529, fax (931) 590-5400,
www.solarpathfinder.com.
Place the bottom edge of the array at least 2
feet (.6 m) above ground to clear rain spatter,
growing vegetation and snow. Keep in mind
that trees and perennial plants will grow taller
in the coming years.
There are two ways to install the solar array.
1. Assemble the array on the ground, wiring
and all, then lift the entire assembly onto the
pole or roof. A system of 300 watts or more
may require the assistance of a backhoe,
boom truck or crane to lift it over the pole.
2. Assemble the array piece-by-piece on the
pole. If the pole is higher than about 6 feet
(2m), it is best to construct a temporary
platform, like a scaffold assembly commonly
used in building construction). A scaffold
system can be rented from a local supplier.
4.3 Solar Array Mounting
Rack
WARNING Your mounting
structure must be engineered
for wind resistance and safety.
Follow the rack (or tracker)
manufacturer’s instructions
that are packed with your rack.
Solar Tracking A solar tracker is a special
pole-mounted solar array rack that tilts
automatically to follow the daily path of the
sun. In clear summer weather, it can in-
crease your daily water yield by 40-50%. (It is
much less effective in winter and in cloudy
weather.)
4.1 Location of the Solar Array 4.2 Solar Array Assembly
Methods
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