Initially, he planned to remove dust from the surface of the photovoltaic cells using a cylindrical brush mounted on the rear of a train. “However, we realised that each time a train passes, it creates an airflow that sweeps away all the dust,” he said.
That seems pretty optimistic in the long run. Even a high power leaf blower won't get all the dust off of a dirty surface, especially if any sort of hydraulic oil, bearing grease or other viscous fluid mists onto the surface.
One thing that has struck me with our own solar panels is that they have to be very dirty before I notice any significant degradation in efficiency. And when they do get completely covered in pollen or leaves, a brief rain is usually enough to clean them.
Until you realize that polan is super stick and is really had to remove. I had a table outside and just 'blow away' dust didn't work at all. You need to actually clean with friction, water and cleaner.