A solar system really needs little attention, but it is not entirely maintenance-free. The goal is to make sure it delivers its designed yield and to catch developing faults early.
Do panels need cleaning?
In Hungary, rainfall is enough for natural cleaning in most places, especially at 15-35 degree tilt. Rain washes off most of the dust. Exceptions include sites near busy roads, construction, farmland or industrial dust sources, and very flat roofs (under 10 degrees) where dirt settles.
Pollen
In spring, pollen can form a thin film, but the next rain usually removes it. The loss is typically a few percent and temporary.
Bird droppings
These are the most critical: a concentrated spot casts local shade that stresses a cell and can even cause a hot spot. If you see it, clean it off, or have bird protection fitted under the panels and along the ridge.
Snow
Do not try to scrape it off with a broom or shovel. Scratches and micro-cracks cause permanent damage, and climbing onto the roof is dangerous. Thanks to the smooth glass and the tilt, snow normally slides off quickly once the sun comes out.
How to clean, if needed
- Clean, soft water with a soft brush or a microfibre cloth.
- In cool conditions, morning or evening, when the panel is not hot (hot glass hit by cold water can crack).
- No chemicals, abrasives or pressure washers.
- Without stepping on the roof if at all possible. On high or steep roofs, hire a professional.
What to check every year
- Inverter: ventilation, dust on the heat sink, error messages, display or app status.
- Cables and connectors: damage, wear, rodent bites, loose parts.
- Mounting structure: bolts, clamps, corrosion after storms.
- Protection: surge protector indicator, breakers, earthing.
- Shading: new shade from a grown tree or a new building.
Monitoring: the cheapest maintenance
The most useful tool is the online portal. Compare daily output with similar days in previous years and with the expected value. A sudden 10-20 percent shortfall in clear weather deserves investigation: a lost string, a tripped breaker or a faulty optimizer all produce this pattern. Both Huawei FusionSolar and Fronius Solar.web send fault alerts.
Hot spots: what are they?
A hot spot is the overheating of a cell or group of cells, caused by shade, a damaged cell or a poor solder joint. A thermal camera detects them easily, and a thermographic survey every 3-5 years, or whenever performance is doubtful, is worth it. Panel warranties typically cover such defects, so document them.
When to call a professional
For lasting performance drops, repeated inverter faults, visible damage, or a burning smell or noise. Do not touch the electrical system yourself: the DC side is always live in daylight. SolarBay also offers an annual inspection package that checks the points above with a written report.
What does it cost and what does it return?
Professional cleaning of a residential system typically costs a few tens of thousands of forints per visit. If dirt losses are under 2-3 percent, cleaning rarely pays for itself. If losses are persistently 5-10 percent, for example in a dusty environment, it does. So decide by monitoring data rather than by the calendar: if yield does not return to the expected level even after rain, cleaning is worth it. A professional makes the call the same way.
