Maintenance & disposal of solar modules

Maintaining a photovoltaic system is just as important as regularly checking the yields. Failures and loss of performance can otherwise go undetected for years and wipe out profits. The most important thing about cleaning and disposal of the solar modules.

Why is the maintenance of photovoltaic systems useful?

PV systems are often sold as maintenance-free. In fact, however, both regular checks by the owners and maintenance by a specialist company are important – for several reasons:

• If damage goes undetected, in extreme cases the PV system will not deliver optimal yields for years. This can mean that the solar system is not worth it in the end.
• Some damage caused by an unnoticed lightning strike, for example, is difficult to detect without maintenance. Under certain circumstances, this can result in a fire hazard. • Many insurance companies stipulate regular maintenance in the fine print. If damage occurs, lack of maintenance can lead to disputes.
• If a fault occurs years later, it can be found more quickly if regular maintenance has been carried out beforehand.

How often does a PV system have to be serviced?

Regular solar panel maintenance by a specialist company is recommended:

• Annually: visual inspection by a specialist company
• At least every four years: recurring inspection according to DIN EN 62446-1 VDE 0126-23-1:2019-04. It is similar to the inspection by the installation company when the PV system is commissioned.

Many insurance companies prescribe both the annual visual inspection and the recurring inspection every four years in their conditions.

What is included in the visual inspection of a photovoltaic system?

During the annual maintenance of the photovoltaic system(either 12 volt lithium battery or 24v), a specialist company checks all accessible components:

• The module field on the roof: for heavy soiling (leaves, bird droppings, dust) and for correct attachment of the modules
• The mounting system: for damage to the mounting frames and the roof as well as for mechanical or thermal distortions
• The cables and lines: for scorched spots, animal damage, external damage and penetrating moisture
• The junction box of the photovoltaic system: for penetrating moisture and electrical safety
• The photovoltaic storage system by means of a functional test
• The residual current circuit breaker using the function of the test button

Photovoltaic maintenance: When is the best time?

The right time for regular maintenance of a photovoltaic system is before the beginning of the sunny period – i.e. at the end of winter. In this way, a specialist company can identify errors before they have a major impact on earnings.

Servicing may also be necessary after special occasions. After a storm, the owners should check themselves whether objects have fallen onto the roof or whether lightning damage is visible. If there are any doubts as to whether, for example, fasteners have come loose after a storm, it is best for a specialist company to carry out a brief inspection again.

Cost of PV maintenance

The maintenance of a photovoltaic system in a one- and two-family house area costs between $200 and $300. Costs can sometimes be saved if neighbors who also operate solar systems agree with each other. In this case, the flat-rate travel fee is only due once.

You can carry out a detailed profitability calculation including maintenance costs with the solar roof check.

Control photovoltaics yourself

Even if the annual maintenance and the regular inspection every four years are reserved for specialist companies: Owners of PV systems should carry out a few simple checks themselves from time to time, for example to identify defective solar modules. This will prevent you from losing out on income if the solar powered generator is not working properly. For example, some damage to the modules is visible to the naked eye.

This is how you can identify defective solar modules yourself:

A look at the display on the inverter is often enough to notice that the photovoltaic system is not working properly.

When operating properly, the inverter gets hand-warm. If it stays cold despite the sun, there is a problem. If in doubt, repeat the check at a time of day when the sun is stronger.

You should also consult a specialist if the inverter hums unusually loudly.

Recognize falling PV yields

Yields drop when there are faults in the photovoltaic system. If they go unnoticed, it can cost a lot of money in the long run. It is therefore helpful to regularly check the solar yield:

Many 12v inverters already have an internal data logger and save the measured values. In the event of a fault, some inverters even send an alarm to the smartphone of the owner or to a specialist company with which there is a maintenance contract.

You can also use digital helpers with additional functions such as the energy saving account or the EnergyCheck app. However, the yields can also be checked manually by regularly noting down the values on the inverter, on the photovoltaic storage unit or on the yield counter.

Another useful method: compare your own yields with plants in the neighborhood. The easiest way to do this is via the web portals of the manufacturers of solar inverters or with regional solar initiatives.

What can I do if the PV yields drop?

If the solar system produces less solar yield per kilowatt of nominal output than planned or than other systems in the vicinity, various causes can play a role:

• error in planning
• wrong inverter
• Dirty or blocked inverters
• too high losses in the cables
• Faulty connection: plugs, contacts, solder joints
• incorrectly polarized modules
• Shading from trees, new buildings, etc.

You can remove dust from the inverter yourself. The remaining causes are usually only recognized by specialist companies during maintenance or a garden center has to cut back high-lying branches.

Why does an inverter break?

It is not uncommon for inverters to simply be dirty and overheat as a result. You can clean the ventilation grille yourself and free up a delivered inverter.

Another common error is overvoltage damage to the inverter. Specialist companies can recognize them during regular maintenance – as well as, for example, wear and tear on the capacitors. Incidentally, damage caused by overvoltage or other causes is replaced by good photovoltaic insurance.

Cleaning the photovoltaic system: When is the right time?

Small solar panels are largely self-cleaning if their inclination is greater than 15 degrees. Then the rain washes away dirt and dust. Snow in winter should be cleared away, because the winter sun can also contribute a significant solar yield. Even coarse dirt such as branches or bird droppings lying on the modules must be removed.

But be careful: When working on the roof, you must be adequately secured! If the solar modules are dirty so that you have to clean them all over, you should definitely consult a specialist company. Because if you clean it incorrectly, you risk losing the guarantee on the solar modules!

How does the disposal of solar modules work?

Photovoltaic modules are subject to the Electrical and Electronic Equipment Act (ElektroG), which regulates the recycling of electronic waste. Private households can dispose of PV modules free of charge at municipal collection points. The owners should leave the dismantling and transport to a solar company. Individual modules can also conduct electricity and break if not handled properly. The solar industry has created a brochure with safety instructions for handling old PV modules.

Solidly planned and installed systems can easily run for more than two decades. It is also possible to use the old metallic substructures for more powerful modules of the next generation (repowering).

Costs for photovoltaic disposal

The costs of dismantling the modules and transporting them to the recycling center should not be underestimated. The owners should therefore clarify before the installation what will happen to the system after it has been taken out of service or replaced twenty years later and who is responsible for recycling. Some recycling companies try to recycle modules that are still usable in other photovoltaic systems.

Do photovoltaic modules contain heavy metals?

In older modules (until around 2014), the rows of cells were still soldered with solder containing lead. Most modern solar panels no longer use lead.

A special case are special thin-film modules made of cadmium telluride. This semiconductor is considered a heavy metal due to the cadmium content. Disposal can only be carried out by suitable specialist companies. The manufacturers of such modules use their own return system, which becomes effective when the modules are purchased. Reserves with independent insurers provide financial security for take-back and recycling. It also applies when the manufacturer is no longer active on the market, which is not uncommon.

Corresponding modules are hardly on the market anymore. If you decide to go with them, make sure that the provider provides you with the relevant information and insurance certificates as part of the sales documents.