This phenomenon—caused by the accumulation of dust, environmental salts, UV radiation, and thermal variations—is generating growing concern in the energy sector, especially in arid zones such as northern Chile. These factors, which may seem superficial, have a direct impact on the efficiency of photovoltaic modules, affecting their performance and service life. This is warned by SERC Chile researcher Douglas Olivares, who along with other professionals are working on strategies to address this issue. 

With more than 10,680 MW of operational solar photovoltaic energy, Chile remains a regional leader in installed renewable energy capacity, according to data from the National Energy Commission (CNE). This figure continues to rise and is expected to double by 2030.

However, this type of energy generation faces a challenge that must be addressed: soiling, which refers to the accumulation of dust and particles on photovoltaic modules, potentially reducing their performance by up to 20%, depending on factors such as cleaning frequency, module tilt, time of year, and type of installation.

Douglas Olivares, a researcher at the Solar Energy Research Center (SERC Chile), points out that “soiling can be more severe in local contexts such as those in northern Chile, where several atmospheric and geographical factors combine. The presence of camanchaca (coastal fog with high moisture content), together with hygroscopic salts and suspended dust, promotes the adhesion and cementation of particles on the surface of the modules. Added to this is the proximity of many solar plants to industrial, mining, or urban areas, which increases the load of aerosols and particulate matter in the environment.”

In fact, Olivares has dedicated himself to studying soiling as a critical problem for the development of solar energy in arid zones, work he has carried out in conjunction with national and international centers; in the search for solutions, he says that “currently, one of the most relevant and operational strategies is the real-time monitoring of the soiling index and local weather conditions. This allows for the optimization of solar module cleaning cycles, adjusting them to the actual rate of dust accumulation and avoiding unnecessary cleanings that could generate additional costs or premature wear.”

Additionally, the professional specifies that research is being developed focusing on improving the resistance of materials to extreme desert conditions, such as high UV radiation and thermal stress. “Specifically, more durable and resistant encapsulants are being studied to extend the service life of the modules,” explains Olivares.

How can its effects be reduced?

Olivares, who is also an academic at the Energy Development Center of the University of Antofagasta (CDEA-UA), explains that “projects are being carried out that seek to address this problem from a strategic and territorial perspective.” An example of this is the project he leads, titled ‘Solar Route and Green Hydrogen: a strategic planning for local energy development’, which has the support of the Regional Government of Antofagasta through the Regional Fund for Competitiveness, Science, Technology, and Innovation (FRPD Fund). This project aims to generate key technical and environmental information on the impact of soiling on green hydrogen generation, a topic that has been little addressed until now but is crucial for the efficiency and sustainability of future energy developments in the region.

“(…) making soiling visible as a critical problem that directly affects the profitability of solar projects (…)”

“The objective is to make soiling visible as a critical problem that directly affects the profitability of solar projects, and that must be considered in regional energy planning, particularly regarding the performance, maintenance, and operating costs of solar plants,” the researcher specifies.

As Olivares explains, “currently there is no specific public policy dedicated exclusively to the phenomenon of soiling, although the issue has begun to gain greater relevance in the scientific and technical fields. Institutions such as CDEA-UA, Atamos – Tec, and SERC-Chile have promoted projects aimed at understanding its technological and economic implications, highlighting it as a critical variable in the operation of solar plants in arid zones. Additionally, initiatives funded by regional instruments, such as the FRPD funds, are enabling the generation of evidence to support future mitigation strategies.”

Finally, the SERC Chile researcher concludes that “it is fundamental for photovoltaic plants and their operators to understand the impact of soiling in greater depth, as this phenomenon has significant implications for the performance, durability, and operational costs of the facilities. If not properly managed, its cumulative effect can negatively impact the efficiency and profitability of projects throughout their life cycle.”