Is it necessary to clean solar panels before the first 10 years of operation?

Photovoltaic solar energy has become one of the leading energy alternatives for both the residential and industrial sectors. More and more people are choosing to install solar panels with the expectation of obtaining a durable, efficient system with low maintenance costs. However, one of the most common questions among owners and investors is whether solar panels need to be cleaned during the first 10 years of operation or whether they can function properly without specific interventions. To answer this question accurately, it is essential to understand the real impact of dirt on solar panels and the role that Photovoltaic Operation and Maintenance plays in the profitability of a solar installation.

Although solar panels are designed to withstand harsh weather conditions for decades, this does not mean they are maintenance-free. The idea that solar panels do not require cleaning during the first years of operation is based on the assumption that rain is sufficient to keep them in good condition. However, field experience and multiple technical studies show that this assumption is not always correct. The accumulation of dust, sand, pollen, air pollution, and bird droppings can progressively reduce the amount of solar radiation reaching the photovoltaic cells, directly affecting energy production.

Dirt on solar panels acts as a physical barrier that prevents sunlight from reaching the module surface properly. Even a thin layer of dust can cause noticeable production losses. In urban environments with high pollution levels, agricultural areas with constant airborne particles, or locations near roads and industrial zones, these losses can easily exceed 10% annually. In more extreme cases, where no cleaning is carried out for several years, performance reductions of up to 25% have been recorded. These figures clearly highlight the importance of incorporating cleaning into a Photovoltaic Operation and Maintenance strategy from the early years of a system’s lifespan.

One of the most common arguments against cleaning solar panels is that rainfall naturally removes dirt. While rain can wash away some superficial dust, it is not sufficient to eliminate adhered residues such as grease, accumulated pollen, or bird droppings. In addition, in areas with hard water, rain can leave mineral deposits that create stains and further reduce panel efficiency. In installations with low tilt angles, water does not flow with enough force to clean the surface evenly, which reinforces the need for controlled and periodic cleaning.

From a regulatory standpoint, there is generally no legal requirement that mandates cleaning solar panels within the first 10 years of operation. Nevertheless, from a technical and economic perspective, cleaning is highly recommended. Professional Photovoltaic Operation and Maintenance contracts include cleaning as a key preventive task because it helps maintain the production levels estimated during the system design phase and ensures compliance with the performance guarantees offered by manufacturers.

The frequency at which solar panels should be cleaned depends on several factors. Geographic location, environmental pollution levels, panel tilt angle, and exposure to external agents directly influence how quickly dirt accumulates. In residential installations, an annual cleaning is often sufficient to maintain good performance, while industrial or commercial systems may require multiple cleanings per year. In large-scale solar power plants, cleaning is systematically scheduled as part of the Photovoltaic Operation and Maintenance plan to maximize energy output and ensure the economic viability of the project.

It is also important to note that improper cleaning can be harmful to solar panels. The use of high-pressure water, abrasive chemicals, or unsuitable tools can damage the protective glass and reduce the module’s lifespan. For this reason, cleaning should be carried out by specialized professionals using appropriate techniques and materials. Within a Photovoltaic Operation and Maintenance service, cleaning is usually combined with visual inspections that allow early detection of microcracks, hot spots, or wiring issues before they develop into serious failures.

Including solar panel cleaning in a comprehensive Photovoltaic Operation and Maintenance plan provides clear benefits from the very first year of operation. Not only does it increase energy production, but it also accelerates the return on investment and extends the useful life of the system. Furthermore, a well-maintained installation offers greater operational safety and reduces the risk of unexpected shutdowns or financial losses caused by poor performance.

During the first 10 years of operation, cleaning becomes particularly important. At this early stage, solar panels retain their maximum production potential, meaning that any loss caused by dirt has a direct impact on profitability. Choosing not to clean the panels during this period is equivalent to accepting avoidable losses that, when accumulated over time, can represent thousands of euros in ungenerated energy. For this reason, an increasing number of system owners choose to contract professional Photovoltaic Operation and Maintenance services from the very beginning of the installation’s lifecycle.

In conclusion, although solar panels are designed to operate for decades, their optimal performance largely depends on the care they receive. Cleaning during and before the first 10 years of operation is not an unnecessary expense, but rather a strategic investment that ensures stable and efficient energy production. Integrating cleaning into a professional Photovoltaic Operation and Maintenance plan allows system owners to maximize solar energy utilization, protect their initial investment, and ensure that the installation meets long-term performance expectations. Ignoring this aspect ultimately means failing to fully exploit the potential of a technology designed to deliver maximum efficiency with minimal environmental impact.