Updated: Feb 18, 2021
Solar panels absorb sunlight as a source of energy to generate direct current electricity which, with the help of an inverter is converted to alternating current for direct use in appliances or storage in batteries for later use. They depend on sunlight to be able to produce the electricity that appliances can run on.
When mounting solar panels, our technicians and engineers at SolarKobo make sure surrounding trees, buildings, walls, other panels, etc. do not cast a shadow on the panels at any time of the day or year.
The reason is because a solar cell’s voltage will drop to its half value if it is shaded and if majority of the cells are covered, the panel will not produce any energy. All the cells are connected in series, that is, directly, or end-to-end. This means that if one cell shaded partially will have its output voltage drop by half, the output of the entire module will also drop by half.
They also tilt the panels. As solar panels are most efficient when they are perpendicular to the sun’s rays, as since the sun shines at an angle to the earth's surface (unlike the rains which fall vertically) they tend to tilt the panels to degrees ranging from 28–30 degrees to optimize efficiency.
Another important reason they have to tilt the solar panels is so the rains can flow off them and in the process help to wash off any accumulated dirt which can inevitably lead to shading.
In Nigeria, particularly, because most solar panels are mounted on roofs, which are already tilted by architectural design, in those cases, technicians do not have to bother about titling them again. In countries where there is less sunlight at different times of the year, the positioning of solar panels has to be changed at least twice a year, first at winter and second at summer time.
Placing the panels where they cannot be shaded and tilting them are standard procedures.
When Is There A Need to Clean Your Solar Panels?
During the harmattan season in Nigeria, especially for those who live around busy untarred roads or other places where dust is constantly being raised by human activities, construction works, or in wintry places where the winds are always busy, there will be concerns about the solar panels being shaded by layers of dust. While the rains and winds always helps to wash off the dust, the efficiency of solar panels in periods of no rain and reduced wind, may drop by up to 20%.
In addition to dust, there may be cases of bird droppings and leaves. This also applies for those in countries that experience snowing.
In these two cases, the solar panels may need to be cleaned.
How to Clean Your Solar Panels.
In most cases, solar panels are installed at potentially dangerous heights that can lead to fatal accidents. In those cases, professional services should be hired.
In the cases where this can be done personally without any risk of accidents, cleaning your solar panels is as easy as cleaning the windscreen of your car or your windows. Use water in which detergent has been dissolved or liquid soap and gently scrub the surface with a rag. Do not scrub too hard to avoid permanently damaging the panels. For thick grime, you can use a soft brush. At most car washes in Nigeria, a hose from which water flows at a high pressure is used. If such a hose is available, it is the best possible recommendation for cleaning off thick grime from your solar panels.
Large Scale Cleaning of Solar Panels
While residential arrays may not require cleaning except in extreme cases, cleaning is a standard and regular operation and maintenance (O$M) requirement for large-scale solar farms. In developed countries with these large-scale installations, there are O&M companies that provide solar panel cleaning services.
Some O&M companies employ a special type of solar panel cleaning machines as shown in the image above or robots as shown below. The goal of such services is to increase the performance of the panels and to make a full return on the monetary investment in them.
SolarKobo provides high-value post-installation operation and maintenance services for its clients in Lagos and elsewhere in Nigeria on order.