[Ichneumon]

What does one 50 mph sand storm or one 1" hail storm do to this array of mirrors?

Several years ago I read an article which mentioned that one of the bigger issues with large-scale solar facilities was simple *dust* and dirt and pollen, etc. Over time it builds up on the mirrors/lenses/solarcells/whatever, and you have to send out a freaking huge army of window washers on a regular basis to keep , or work out some automatic system of cleaning the collectors. Either way, you have to budget a surprisingly large amount for maintenance operations, plus probably a heck of a lot of water for the washing, and likely a soap or other cleaning solution as well. Now you've got drainage and run-off to worry about, and environmental effects, and...

[Iris7]

There is a trough style reflector power system near Barstow. Saw it from a distance. Mirrors are glass faced.

To clean these mirrors they use an automatic high pressure spray system that uses pure deionized water. Otherwise there would be excessive deposits on the mirrors. (I would think a small amount to 100% evaporating surfactant would help.)

Usually the system is run every night. Deserts are dusty. Some human has to check a zillion nozzles for plugging, distorted spray patterns, pump pressures, leaking fittings, etc. This also means a large water consumption.