[Publius6961]

How often do you change out your storage batteries, and what does it cost, please?

And how often do you clean the array and how long does it take?
In the valley the dust is ubiquitous and eternal, and the efficiency plummets unless the cells are kept clean.

[null and void]

And how often do you clean the array and how long does it take?

Haven't ever. They are angled with the roofline, wind and rain keep them "clean enough"...