REC ALPHA Series User manual

Fig. 2: Dust fall on solar panels.
Fig. 1: An example of dust build-up on solar panels over time.
Quick guide to cleaning
Ensuring the best performance of REC solar panels
Clean solar panels help ensure solar installations generate optimal electricity. All REC panels have been
designedforeasyinstallationandminimalmaintenance,however,dust,pollen,leavesandothercontaminants
oen find their way onto the panel and soil the surface. To overcome this, REC panels are manufactured so
that normal and regular levels of rainfall will clean them naturally if installed at a sufficient angle.
Nevertheless, factors such as the amount of dust and dirt in the
air, the amount and regularity of rainfall and the optimum angle of
installation are dependent upon the location of each installation
and any dirt-resistant properties of a panel will not necessarily
guarantee a permanently clean and dirt-free surface.
The dirt itself will not harm the panels, but allowing it to build
up over time can affect system performance. Therefore, to
optimize electrical output, it is recommended to clean the
panels when dirt can be seen on the glass surface.
BEFORE CLEANING
Damaged panels can present a lethal shock hazard due
to leakage currents. The risk of shock is higher when
panels are wet. Before cleaning, thoroughly inspect
panels for cracks, damage, and loose connections.
Cleaning of panels should only be carried out when the panels
are cool to avoid thermal shock. During the day, ambient
temperature rises and the panels heat up as they produce
energy, usually to around 20°C above the surrounding
conditions. Applying cool, cold or lukewarm water to hot panels
can cause components (e.g., glass) to shrink rapidly, potentially
causing cracks and breakages. Inversely, the application of
hot or boiling water to cold panels may cause rapid expansion
of components and similar breakage. Therefore, only water at
ambient temperature should be used.
Panel cleaning should be carried out before reaching working
temperature i.e., early morning and must only be cleaned
with water at ambient temperature to avoid thermal shock.
Ideally, de-ionized water should be used to clean the panel. De-
ionized water is water that has had the mineral ions and salts
removed. If de-ionized water is not available, rainwater, tap
water or diluted alcohol may be used as a secondary solution.
Ensure the water used is free from grit and physical
contaminants that could damage the panel surface.
STAYING SAFE
Solar installations come in different shapes and sizes, so the
following steps are meant as a guide only and the installation
should be assessed for safety and access before commencing
cleaning. If in doubt at any time when cleaning the panels, stop
and obtain professional advice.
Safety
When working at heights, use fall and personal protection
measures throughout the cleaning process.
The panel is designed to carry the certified load across its whole
surface area. Standing on the panels applies force through a much
reducedsurfacearea,whichcanfar exceedthecertifieddesignload.
Equally avoid dropping or allowing any objects to fall on the panel
as the impact may cause the panels to break or detach from the
mounting structure, possibly resulting in damage or personal injury.
Remember: Never at any point stand on, walk on, lean on
or apply pressure to the panels as this can cause both
visible and non-visible damage to the panel.

Fig. 3: A clean and functioning solar installation
Note: This guide is intended to help ensure a safe handling between solar panels and between other balance of system components. REC accepts no responsibility for
any damage caused by improper or incorrect use maintenance or cleaning of the panels. The Warranty on the product is only valid if the instructions in the appropriate
Installation Manual are observed at all times.
CLEANING THE PANELS
Washing the panels
A standard flexible garden hose with domestic water pressure
may be used to apply as much water to the panel or array as
necessary, allowing the water to run down the entire surface.
Although REC panels are manufactured to international
standards and have passed all relevant certification tests, the
useofhighpressurehosesforcleaningis not permiedasthese
may exert pressure in excess of the certified load and cause
impact damage, damage to the frame bonding, the laminate or
cells and force water between the glass and frame.
The use of pressure or steam cleaners and high pressure
hoses, knives, blades and metallic sponges is not
permied on REC panels and will invalidate the warranty.
Dependent on local conditions, the rear of a solar panel
can also be affected by growth such as moss, mold
or lichens. This is not generally a cause for concern,
however if cleaning the rear of a panel is desired, care
should be taken to ensure there is no damage caused to
the backsheet by simply clearing the growth by hand or
with a so sponge. REC does not provide warranty for
the application of any sprays or treatment.
For further cleaning
If the panels require more cleaning effort to remove stubborn
marks, use a so sponge, microfiber cloth or a so and non-
abrasive brush and lightly wipe over the affected area. This may be
mounted on an extension pole for an extended reach. Treatment in
this manner should remove any loose soiling from the panel glass.
Care must be taken not to scratch, mark or introduce any
foreign elements to the glass surface
If marks still remain on the panels, a mild biological and
biodegradable washing-up liquid may be used on the panels.
The panel must be immediately rinsed with plenty of water.
Rinsing
To rinse the panels, apply as much de-ionized water as required
to the highest point of the panel or system until all the loose
soiling and/or cleaning solution is washed off. If soiling remains
on the panels aer rinsing, repeat the cleaning procedure or if
any soiling continues to prove stubborn, IPA (Isopropyl Alcohol)
with a concentration of less than 10% may be be used. Acid or
Alkali detergent must not be used.
Drying
Thebest wayto dry panels is toleavethemto dry naturallyin the
air. If for some reason this is not possible, they can alternatively
be wiped dry with a chamois or by use of a rubber squeegee with
a plastic frame on an extension pole. Wipe the panel surface
from the top downwards to remove any residual water from the
panel glass, but pay aention that any leover grains of dirt or
sand do not scratch the surface of the panel.
Avoid puing pressure on the panel surface when drying
Snow
If required, snow can be brushed or wiped from the panels in
the same way as described for cleaning (i.e., with a non-abrasive
brush). Bewareofsnowslippage from higher areas. However, as
snowfall generally occurs at times of the year when irradiation
is at its lowest, clearing snow build-up from the panels is not
essential for maximum performance.
Congratulations, aer completing this process, the panels are
now clean and working at optimum efficiency again. With the
right practices, cleaning solar panels should be easy and safe.