Malta is testing systems that can detect solar panel defects and production losses earlier.

Researchers used ten solar installations in Malta as laboratories under real conditions to test methods for identifying faults and production losses before they cause larger problems. The PROMISE project, funded through the European Horizon program, combined sensors, digital replicas of the installations, automated data analysis, and practical training for technicians in an environment exposed to very hot summers, salty air, and episodes of Saharan dust.

In short, Malta has about 3,000 hours of sunshine per year, but high temperatures, marine air, and Saharan dust storms create difficult conditions for the long-term operation of photovoltaic panels. Researchers monitored ten real installations using sensors that measure electricity production, solar light, wind, and temperature. The data can indicate when maintenance intervention is needed. The project developed digital replicas of the installations and artificial intelligence-based tools for testing scenarios and automatically identifying deviations that may signal a fault. Students and technicians were trained to examine the panels through visual inspections, photographs, checklists, and electroluminescence tests that can reveal cracks or hidden defects. Small solar installations represent about half of the European photovoltaic capacity and may encounter similar monitoring and maintenance issues, especially when owners do not have specialized service contracts.

Malta offers favorable conditions for solar electricity production, but it is also a demanding environment for equipment. The island has about 3,000 hours of sunshine per year, and the panels are simultaneously exposed to high temperatures, humidity, and salt carried by marine air, as well as dust periodically brought from the Sahara.

These conditions allow researchers to observe problems in a shorter timeframe that may occur more slowly in other areas of Europe. The president of the Foundation for Innovation and Research – Malta and the coordinator of the PROMISE project, Brian Azzopardi, explained that systems that withstand the Maltese environment should be able to function in other European regions with less severe conditions.

PROMISE analyzed for three years methods for improving monitoring, maintenance, and reliability of photovoltaic systems. The project did not only focus on the performance of new panels but also on how already installed systems can be maintained in operation for a longer period.

The use of solar energy has rapidly expanded in Malta since around 2010, supported by public grants and community programs. According to estimates presented by Azzopardi, the adoption level has reached about 20%-22%, after previously being almost non-existent.

The increase in the number of installations has made the maintenance issue more visible. A photovoltaic installation can continue to produce electricity even if one or more panels are not functioning at normal capacity. The owner may only notice the fault after the production loss becomes significant enough to appear in bills or in the overall system data.

Delay can allow for the deterioration to extend or for production losses to accumulate. The project team tried to identify changes earlier, before the fault becomes evident to the owner.

Researchers installed commercially available sensors that measure the amount of electricity produced, solar radiation, temperature, and wind speed. Comparing actual production with weather and operating conditions allows differentiation between a normal decrease caused by clouds and a loss that may indicate a technical problem.

The data was entered into a monitoring system capable of estimating when maintenance might be necessary. The goal is for checks and repairs to be scheduled before the problem causes a significant drop in production.

The team also developed digital twins, computer replicas of real installations. Such a model reproduces the system's behavior and allows testing of various situations without direct intervention on the physical installation.

Researchers can compare data received from panels with the results that the model considers normal under the same conditions. A persistent difference between actual behavior and estimated behavior may signal a fault, new shading, dirt, panel degradation, or a problem with another component.

Artificial intelligence-based tools continuously analyze data and automatically signal anomalies. The system does not repair the installation and does not definitively determine the cause of a problem, but it can draw the technician's attention to a point that requires checking.

Monitoring took place in ten "Living Labs," real installations used simultaneously for energy production, research, and training specialists. This approach allows testing tools in everyday conditions, without being limited to experiments conducted exclusively in the laboratory.

Photovoltaic installations can lose performance for various reasons. Dust, dirt, and bird droppings can reduce the light reaching the cells. The construction of a nearby building can create a shading area that did not exist when the panels were installed, and temperatures, salt, and mechanical stresses can contribute to the degradation of components.

Photovoltaic systems have few moving parts, but this does not mean they do not require checks. Cables, connections, inverters, mounts, and the surface of the panels can suffer defects or degradations that reduce production or affect the safety of the installation.

The issue is particularly relevant for small installations on residential rooftops. Their owners do not always benefit from comprehensive maintenance contracts or advanced monitoring systems, and some faults may go unnoticed for an extended period.

The project addressed staff training as part of the same issue. The expansion of solar capacity creates the need for technicians and researchers who understand how installations work, can interpret data, and can identify physical defects.

Students who participated in international summer schools visited the installations and worked with data from real systems. They learned to conduct visual inspections, photograph and document defects, and use structured checklists.

A more advanced method used in training was electroluminescence. During the test, electricity is introduced in reverse into a solar panel, and the cells emit a very weak infrared light, invisible to the human eye.

Specialized cameras can record this light and show areas where the cells do not function uniformly. The method allows for the detection of very small cracks and other defects that may not be visible when the panel is examined from the outside.

The team also used games, matching exercises, and simulations to prepare participants. One of the games simulates the situation of a technician who must diagnose an installation, decide what interventions are necessary, and manage a maintenance budget.

The exercise reflects the fact that maintenance does not only mean identifying a fault. The technician must interpret the data, prioritize the intervention, discuss costs, and coordinate the repair with the owner or manager of the installation.

For a younger audience, researchers also created a show called "Dance of the Photon," in which the movement of dancers explains the transformation of sunlight into electricity inside a photovoltaic cell. The activity was designed to present a technical process in a more accessible form.

The importance of maintenance is not limited to Malta. Small installations represent about half of the total photovoltaic capacity in Europe, according to information presented by the project. Many are located on homes or on the properties of small businesses and may have limited access to monitoring and specialized service.

The tools tested in Malta could help owners and technicians identify unusual production drops earlier. Their application in other countries will depend on cost, compatibility with existing installations, data quality, and the staff's ability to interpret alerts.

The project does not demonstrate that any system that works in Malta will automatically withstand anywhere in Europe. Climate conditions, types of installations, and causes of faults differ between regions, and solutions must be validated for the environment in which they are to be used.

PROMISE was funded through the European Union's Horizon research and innovation program. The project brought together technical research, testing in real installations, digital tools, and training activities for the photovoltaic sector.

Digital twins are used in various sectors to reproduce the behavior of a piece of equipment or a physical system. In the case of solar installations, they allow for the comparison of actual production with estimated performance and the simulation of effects caused by weather, shading, degradation, or faults.

Predictive maintenance uses data to estimate when a problem is likely to occur or when an intervention becomes necessary. It differs from maintenance performed only after a fault and from checks carried out at fixed intervals, regardless of the state of the installation.

The expansion of solar energy increases the number of pieces of equipment that need to be monitored over several decades. The actual operating duration and the total amount of electricity produced depend on the quality of components, installation, local conditions, and maintenance performed after installation.

The results and experience gained in Malta can be used for further research and for the development of training programs. The published material does not specify that the tools created have already become commercial products available in all European markets, nor does it quantify the cost reductions or increased lifespan achieved through their use.