Long life of solar panels. Service and care

10/09/2021

Long life of solar panels. Service and care

You have just bought solar panels. You received a 25–30-year warranty on them. You plugged them in, sat back, relaxed and prepared to spend next years paying paltry amounts for electricity, or even making a profit. You’ve done everything right, but your panels will need care in order to last and keep you happy with uninterrupted operation. Regular maintenance, just as with a car, will not only keep your solar power plant running efficiently and safely throughout its lifetime, but will significantly extend their lifespan.

Why maintenance is necessary

The common statement in marketing texts that solar technology belongs to the category of “install and forget” is unfortunately not yet true. Today, they are quite close to this state, but they have not yet reached it.
What is solar power plant maintenance? – It is a set of operations for monitoring, checking, repairing, upgrading and cleaning panels and equipment to prevent and correct performance problems.
The need for maintenance is primarily due to the fact that in the course of operation solar power plants are exposed to many destructive factors, including natural ones:

accumulation of dust, dirt or snow reduce power generation;
cracks from hail, falling heavy branches, from extreme seasonal temperature fluctuations open access for moisture to the electrical conductors, which causes short circuits, cells failure and as a result – a drop in the capacity of the solar power plant;
oxidation, damage to the wire insulation also lead to malfunctions of solar panels and their failure.

As we can see, the effects of these factors ultimately lead to a decrease in the efficiency of the solar power plant, which automatically extends the period of return on investment.
Even a rough estimate of the cost of repair, loss of downtime or reduced productivity gives reason to think about the need for maintenance.
Organization of qualified service, of course, will require certain financial costs, which can be reduced at the stage of installation and connection of solar panels. For example, mistakes made during installation can have a negative impact on the operation of the solar plant, and their elimination will require additional payment to the service company. Therefore, Swiss Solar AG has developed an Installation Manual for its customers, following which will help to avoid such mistakes.
It should be noted that professional installation of a solar power plant cannot be cheap, but the money saved on it will never outweigh the benefits of correct operation of the plant throughout its lifetime (up to 30 years or more).

Do-it-yourself maintenance

Despite the fact that the solar power plant is a complex set of electronic equipment that generates electricity, a number of simple maintenance operations is also available for self-performance.
The solar panels can be cleaned of dust, dirt, snow and other contaminants associated with local climatic conditions and negatively affecting the performance and operability of the system.
The following rules are important when servicing the panels:

only clean, softened tap water, a soft pile brush or a special disc brush capable of rotating under water pressure should be used for washing;
a large layer of snow is cleared with special tools (scrapers with soft nozzles), which do not cause damage, while a thin layer of snow or ice crust in most cases melts on their own as the air temperature rises.
when working at heights, safety rules must be complied with (special non-slip shoes, the use of a safety rope)

The maintenance operations should be carried out every season.
Another type of self-service you can perform is visual inspection. Its necessity is indicated by a steady decrease in the performance of the solar plant. It can be detected by checking the readings of the inverter, which monitors the condition and performance of the plant. Advanced models of these devices provide continuous monitoring of system parameters and display fault messages on the built-in screen. Moreover, with the built-in Wi-Fi module, the owner (or a service organization) will receive reports and error notifications remotely.
Visual inspection allows you to identify malfunctions that have caused a decrease in the efficiency of the solar power plant.
What are the inspection steps?

check the reliability of panel fastening – the detection of loose bolts, damaged struts, signs of corrosion;
detection of solar panel shading, which may be caused by overgrown trees, temporary and permanent structures that make it difficult for sunlight to reach the panels (Fig.1);

Fig.1 Shadowing effects [1]

check the condition of the solar modules:
any hot spots – highlighted by dark (brown/black) spots around the damaged cell (Fig. 2);
any plastic damage due to ultraviolet radiation (yellow or brown coloring of cells) (Fig. 3);
any damage to the glass coating – cracks, chips (Fig. 4);
any signs of delamination – peeling of the photoelectric layer of the modules (Fig. 5)

Fig. 2 Hot Spot [1]

Fig. 3 Yellowing [1]

Fig. 4 Glass Breakage [1]

Fig. 5 Delamination [1]

Detection of such malfunctions requires immediate replacement of the damaged modules. Contact the manufacturer for assistance or contact the company that sold the equipment.

Professional after-sales service

The level, scope of services and capacity of service companies (O&M) are considerably different from those available for self-care and maintenance of the solar power plant. Maintenance work begins with a technical audit, which identifies possible critical violations and factors not considered in the design and installation stages of the system, but which have a significant impact on the effectiveness of its work.
These are:

errors in the equipment selection (wire cross-section, quality of connectors);
poor quality of installation (poor grounding);
influence of geographical location of the station, which wasn’t considered;
incorrect choice of module installation angle;
presence of shading.

Early detection and correction of such defects allows you to avoid more complicated problems in the course of maintenance.
The use of 24-hours remote online monitoring allows both solar plant owners and O&M companies to monitor and detect parameters such as:

current system indicators (voltage, current, capacity);
volumes of consumed and generated electricity;
any damage to system elements;
any emergency conditions;
degree of charging/discharging of accumulator batteries

Prompt errors and emergencies reports ensure a quick response and troubleshooting. Remote equipment software updates are also available.
To perform operational and maintenance work, service companies use state-of-the-art equipment, which allows them to perform complex measurements and tests necessary to identify malfunctions without outsourcing. These include:

aerothermography of solar module arrays;
local ground-based thermal imaging inspection of photovoltaic modules and power equipment;
measurement of volt-ampere characteristics of solar modules;
other standard and specialized tests (Fig. 6).

Fig. 6 PV modules checking methods [1]

Service companies also undertake preventive inspections and measures to clean the surfaces of the modules, carry out routine repairs and troubleshooting.

Choosing a service provider

As you can see, no matter how many solar modules are used in your solar plant – a few dozen or a few hundred – you should not rely on your own efforts to maintain them. Professionals will not only guarantee the detection and elimination of all the deviations in the system operation, but also do it faster and more efficiently.
If you agree, the only question that remains is where to find and how to choose a service company that you can trust about the maintenance and finally forget about the problems.
The ideal option is to sign a service contract with the company that conducted the installation and adjustment of your solar plant. However, for a number of reasons it is not always possible (no maintenance provided, bad reputation, the company closed). In this case, the search should be conducted according to certain criteria to avoid bad choice. That might not only help you find a service company, but also to find specialists to solve a particular problem:

availability of certified specialists for PV systems and their maintenance;
availability of equipment for remote monitoring, diagnostics and solving problems with solar modules and other solar plant equipment;
ability to respond quickly to arising problems.

Before signing a contract, make sure that the company has a sufficient number of qualified employees and the ability to attract specialist consultants in complex cases. The contract should be sure to agree on the frequency of service (1-2 times a year or more frequently) and the time of arrival of company employees to the site in case of emergency (usually within 24-48 hours).
It is also worth paying attention to the transparency of the pricing policy, its compliance with the scope of services provided, their quality and speed of delivery. In other words, you should clearly understand how much you have to pay for the selected services and what you will get for the money.
Remember – every extra day of station downtime is an additional financial loss.
References:
[1] https://www.sciencedirect.com/science/article/pii/S0960148118313545#fig1