G'day, I hope this is the right thread to ask this question. I have a rural property north of Sydney that is solar powered. I've noticed in recent years persistant contrails forming cirrus clouds on a much more regular basis. This clouding over effect reduces the amount of sun rays hitting my panels, resuting in longer charge time for the battery bank and on some days, reliance on the back up generator. My question relates to to whether something has changed in our atmosphere in recent times to increase the prevalence of persistant contrails because I have had this property for many years and this has only become a problem in the last 2-3 years. Has their been a dramatic increase in air traffic flying at altitudes that produce persistant contrails or is it weather related?