When and how often should solar panels be cleaned?
Published on September 28, 2026 — Speed 3D Services
There is no single cleaning frequency for all photovoltaic installations. The schedule shall take into account the notice of the signs, their environment and the observed soiling. To decide on a passage, it is better to use these elements than to automatically retain a monthly or semi-annual cleaning.
Start with the needs of your installation
First, find the recommendations for maintenance of your modules and the commitments already provided for in your maintenance contract. A periodic inspection of the installation is not necessarily a systematic washing of all surfaces.
In particular, the Trina Solar manual stresses that low inclination can make cleaning more frequent and that dust, leaves and dejections of birds can create shadow zones on the cells. The context of the building therefore counts in the choice of calendar. Source: Trina Solar, Vertex manual, cleaning section.
A first documented observation provides a useful basis. Note the date, visible deposits and recent circumstances. If possible, take your photos from the same safe point to make comparison easier.
After dust or pollen: observe before programming
After an episode of visible deposits, check the appearance of the panels from the ground or from a safe location. If you distinguish persistent traces, send a photo to the professional rather than trying to reach them.
Rain can remove part of the dirt, but its passage does not prove that all surfaces are clean. Conversely, a few visible traces are not sufficient to determine the economic benefit of an intervention alone. The package leaflet and examination of the installation shall remain the reference points.
In the Alpes-Maritimes, use the observations specific to your address. A villa close to trees, a building in the city and an installation on an open building do not necessarily have the same needs. The municipality is not enough to set a frequency.
Is there a reduction in production that requires cleaning?
Lower production alone does not identify the cause. Before assigning the deviation to the dirt, gather the available surveys, the relevant dates and any messages from the inverter. Send these items to your installer or maintainer.
Comparing two randomly selected days does not dissipate the effect of cleaning. To track your installation, keep a history of the maintenance passages and reported anomalies. This file will be more useful for a diagnosis than a general promise of gain.
Choose the niche with the professional
The timetable must also incorporate the conditions for intervention. Trina Solar does not recommend cleaning at the hottest hours in order to limit thermal stresses. The professional must adapt the slot to the package leaflet, the weather and the means of access. Source: Trina Solar cleaning instructions.
When making an appointment, ask how a pass will be postponed if the conditions are not appropriate. For an occupied site, also specify opening times, access times and times during which intervention can be organized.
Frequently asked questions
Do we have to clean in the spring?
Spring may be a period of compliance, but it is not a universal obligation. Retain the identified needs and panel-specific recommendations.
Does an annual subscription necessarily include washing?
The content depends on the contract. Check if visits include inspection, cleaning or other operations, and under what conditions.
How do I decide the next passage?
Prepare photos and history, then specify the need and perimeter. Our guide to rates and specifications helps you compare proposals. You can also forward your request to Speed 3D Services.