Dubai study finds PV robots cut daily soiling below 0.02%

Every day in Dubai’s desert, dust settles on solar panels and quietly cuts their performance. At a test facility beside the Mohammed bin Rashid Al Maktoum Solar Park, a DEWA research team put five autonomous dry-cleaning robots through real outdoor conditions, comparing bristle brushes with microfiber cloths across fixed-tilt systems and single-axis trackers.

The robots produced a clear operational result. Daily cleaning reduced soiling rates from approximately 0.14–0.33% per day to below 0.02% per day, while measured cleaning efficiencies ranged from 69–99%. The test field contained 164 crystalline-silicon modules rated between 445 W and 505 W, including both monofacial and bifacial designs.

The more reassuring finding came from the inspections beneath the surface. Electroluminescence and dark lock-in thermography testing found no robot-induced cell cracks or electrical defects, according to the study. That matters because a cleaning machine must remove dust without turning maintenance into a source of damage.

The trade-off appeared on the module coating. Repeated cleaning caused minor wear to the anti-reflective layer, and bristle-based systems produced more abrasion than cloth-based ones. The team also flagged battery overheating, inadequate ingress protection, corrosion, frame misalignment and UV degradation of polymer components.

So what, concretely? Solar-plant operators have evidence that robotic cleaning can sharply reduce desert soiling, but not yet a universal plug-and-play solution. Before deployment, DEWA recommends a 12-point checklist covering battery thermal management, at least IP65/IP66 protection for electronics, UV- and corrosion-resistant materials, PV-specific abrasion tests, SCADA-based fault verification and monitoring for frame deformation.