Maintenance of photovoltaic systems for more safety & efficient operation

The need to maintain a conventional heating system or complete solution is never questioned, it is simply taken for granted. Maintenance costs are already included at the planning stage. For a photovoltaic system (photovoltaics or PV system), this is not yet established to the same extent. One reason for this is the longevity of solar modules, the main component of a PV system. Nevertheless, servicing them pays off. This is because a solar technician checks all components and connections of the system and replaces them if necessary. This increases the longevity of the entire system, ensures safe operation and also consistently high yields. In this guide, you can discover which specific tasks are part of a service, how regularly it should be carried out, what the benefits are and what costs you should expect.

What work does a photovoltaic system service involve?

Maintenance work basically includes the visual inspection of all elements – from the modules, cabling and lines to the inverters and the power storage unit  system. In addition to checking for proper functioning, this also involves detecting weak points and faults. The contractor repairs all minor damage directly on site and, depending on the availability of spare parts, soon after during a subsequent visit. Minor damage or faults may be worn or porous cable insulation, loosened screw connections or terminals. Special attention is paid to the modules themselves. Thermographic images are used to detect hotspots and defects. The contractor also looks out for stresses that may cause the glass to break. In addition, the PV surge protection is tested along with the mounting system and the roof structure. A final step is to check the software. In brief, the contractor inspects the following components on site:

• Modules

• Fastening and roof structure

• Cables and connections

• Inverter

• Surge protection

• Power storage unit

• Software

How often does a service have to be carried out and is there a service obligation?

Generally, there is no statutory service obligation for private system owners. However, it does apply to commercially used systems. Whether you have your system serviced is up to you. The maintenance interval is also an individual decision. DIN VDE 0105-100 (operation of electrical systems) recommends regular maintenance at four-year intervals. How often a photovoltaic system should actually be serviced depends on various factors. The following discussion is for orientation purposes only. The best thing to do is to communicate with your local contractor.

• Site conditions –– Among other things, environmental influences such as pollution from the surroundings play a role. Nearby roads with heavy traffic, large construction sites or farms with livestock result in a requirement for more frequent cleaning and maintenance by the contractor to ensure efficient operation. The type of building can also play a role. This relates to the potential danger in the event of a fault.  

• Insurance –– Some insurance providers require regular maintenance. Otherwise the insurance company may refuse to cover costs in the event of a claim.  

• Installation –– The decisive factor is the angle of inclination. In systems with an angle of inclination of more than 20  degrees, there is a good self-cleaning effect. Dust and dirt are regularly washed off by rain. If the modules are mounted flat, more dirt could potentially accumulate. Here, too, the location is crucial.  

The optimum interval is largely dependent on the aspect of cleaning the modules and other components. Dust and dirt settle everywhere and can exacerbate minor defects or affect the system yield. Therefore, cleaning should be carried out regularly by a contractor or should be requested as part of the service.

The benefits of maintenance in summary

Even though PV systems are low-maintenance due to their long service life, their output does decrease after a few years. We have shown the causes of this in the previous section. The loss of yield is often not noticed because this process takes place very slowly. To ensure consistently efficient operation in the long term, maintenance of the photovoltaic system is recommended. In addition to the positive effects on output, the service life of individual components and the entire system is increased. Faults can also be detected at an early stage. This in turn protects against damage and minimises the potential of failures or fires caused by faulty components.

Maintenance costs for PV systems

The costs for servicing a photovoltaic system depend on various factors. The system size and the effort required are the decisive factors. The latter depends on whether many repairs have to be carried out, whether certain components require additional maintenance and whether specific characteristics of the location have to be taken into account. It is therefore not possible to name a flat fee. It is best to communicate with your contractor beforehand. Address the pricing of repairs and follow-up visits before the actual service. However, you should also consider the contractor's travel costs and the cost of labour. Cleaning the modules often has to be arranged paid for separately. If you decide to have a PV system serviced regularly, a maintenance contract is worthwhile. This is often cheaper and saves you the time of looking for a new contractor every time.