scramjett wrote:Out of curiosity, does anyone hose/clean their solar panels? If so, what time of year and how often? I usually hose mine down from June to September/October about every 2 weeks (unless it rains, which is rare in those months in Sacramento, but not unheard of).
I clean my panels every few months, depending upon what storms have blown through. A rainstorm will simply do the job for me, but if it rains and then a blustery dust storm hits... they end up caked with dirt.
I do not hose them off. About a half-hour before sunset I climb up on the roof with a bucket of water, plus a half-cup of vinegar added, and clean them with a dual felt-squeegy attachment for washing windows. Of course, this is easy for me to do since we have a flat roof (Santa Fe style desert home). Cleaning off panels on a traditional, peaked roof would be much harder.
Funny thing, however: I do not notice much difference in my array's output whether the panels are clean or dirty. On back-to-back sunny days, the first day dirty, the second day clean, the difference between the kWhs produced seems negligible. In fact, I once noticed that they produced a bit more dirty than clean. Go figure!