Plant checks and refitting or repowering can increase the performance of a PV plant

PV system maintenance

Maintenance of a solar installation: from the system check to refitting and repowering

Efficiency plays an important role in the operation of a solar system. After all, simply installing the PV system is by no means the end of the story: regular maintenance is essential in order to ensure optimum yield from the individual solar panels. Although PV systems are generally low-maintenance and can function for years without problems, they are after all an electrical system. This means that there are legal requirements for regular inspections which have to be observed by system operators.

For this purpose solar system operators can commission a service provider to carry out this maintenance in the form of system checks and, if necessary, refitting or repowering measures. The expert team from the SENS Service division specialises in the optimisation, monitoring and repair of PV systems.

In general, a distinction can be made between three types of maintenance:

1. corrective maintenance

2. preventive maintenance

3. predictive maintenance

Corrective maintenance involves repairing the system when an error message is received. While predictive maintenance is still an option for the future, since it involves intervention based on historical and real-time maintenance-relevant data, preventive maintenance is increasingly being used today. This has the advantage that maintenance is not only carried out in the event of a problem, but takes place regularly in order to ensure the optimum operation of the system. This prevents breakdowns and therefore saves costs. The following text deals with preventive maintenance.

For such cases SENS offers its customers block maintenance with standardised contracts. These guarantee transparency and leave it up to the customer to decide what measures are taken during maintenance. In addition to the corrective and preventive services mentioned above, the specifications of such a maintenance contract also include expert reports, system checks and plant monitoring. The maintenance of an existing system is carried out in several steps.

Step 1: a system check as the basis for PV system maintenance

So-called “system checks” form the basis of the preventive maintenance of solar systems, which aims to help guarantee a loss-free yield. This represents an analysis of the current situation. A system check primarily serves to identify faults and optimisation potential in the existing system, and to remedy them directly in the short or medium term. Among other things the material of the cables, the characteristic curves, the setting of the current regulators, the type of inverter installation and the cable laying on site are recorded. For example, faulty PV modules or inverters need to be identified. This check enables the current status of the system to be determined, and the potential for improvement becomes directly visible.


Step 2: planning of retrofitting, conversion, refitting or repowering measures

Once the system check has been successfully completed, our experts can evaluate the results: together with the customer a plan for retrofitting, conversion, refitting or repowering measures is drawn up. At this stage manufacturer specifications, the regulations of the grid operator, the applicable standards and regulations as well as local weather conditions must always be taken into account. Often it is sufficient to replace defective components if they no longer meet the latest technological advances, or show functional defects.


Step 3: resource-saving procurement of materials

As soon as the planning of the agreed measures is completed, implementation can begin. The procurement of materials plays a major role in this. SENS makes sure that the requirements are determined as precisely as possible, in order to then save resources to the maximum extent. This also means considerable cost savings for the customer.


Step 4: refitting and repowering the solar system

After all the basic conditions for maintenance have been clarified, the refitting or repowering of the PV system can begin. Both these technical terms are not protected, and essentially describe an upgrading of the entire system or at least individual system components. For the experts at SENS, refitting means the improvement of components not relevant to production, such as the remote monitoring system. In contrast to repowering, the effect here is often underestimated. However, a change of monitoring provider with the possible replacement of the data logging hardware can also make a significant contribution to improving reaction times in the event of a fault, and so subsequently increase the yield of the installation. Due to technical developments in particular, there is often a need for a system upgrade.

At SENS, repowering includes the modernisation or expansion of the existing PV system, which mainly affects the electricity-generating components such as the solar panels and inverters. The aim is to increase the efficiency of the system again, taking into account in particular the remaining service life, the relevant feed-in tariffs and the additional yield to be achieved. These factors are an indicator of whether repowering a solar system is worthwhile in terms of efficiency.

In Germany, maintenance work is carried out in person by our service teams. However, SENS undertakes maintenance operations worldwide and has teams in the UK, Italy and Spain who carry out the work locally. Are you interested in the maintenance of your solar system?


You want to learn more about practical examples of refitting and repowering? Read our article "Refitting and repowering PV systems"


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Picture: Shutterstock/HQuality

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