Interesting observations from a newbie

CALLD
CALLD Solar Expert Posts: 230 ✭✭
Since installing my monocrystalline panels some of the most surprising things I noticed were:

1) A sunny weather forecast means nothing when trying to work out what to expect from your panels. Hazy sunshine caused by the warm air mass before an approaching cold front is actually just as frustrating as an overcast sky. Production can be as low as 50% of a crystal clear day. Smoke from bush fires actually seams to be less of a problem than high humidity.
2) Partly cloudy weather after a cold front has passed can often yield just as much or more daily production than a typical clear day. The cold air seems to much clearer than normal so the sunlight is more intense. I've often seen my panels pushing out (consistently) 10-15% more than there nameplate capacities in such conditions.
3) The "Edge of Cloud effects" is scary! Altogether my panels should not be able to supply a current of more than 25.5Amps (this is the cumulative isc) The charge controller is rated at 30A. I have seen 29.7A on the display before when the sun is near the edge of a cloud. This was observed on a winter's day with the sun at an altitude of 38degress from the horizon. My panels are angled at 40degrees from zenith. I have yet to see what can happen in spring or summer when the sun can hit the panels head-on and get up to 80degrees of altitude. Hopefully it won't get above 31.5A which is where the charge controller will cut-out for 60 seconds every time this happens. This could be seriously annoying if it were to happen on a partly cloudy day where those surges are very usefull for "cramming amps into the batteries"... The affect is definitely due to increased radiation and has little to due with temperature. I have tested this by hosing down my panels on a hot day and noted the effect of the cooling was less than 10%. The edge of cloud effect yields consistently powerful surges of 20-30% more current before or after the cloud passes.

Comments

  • KenZ71
    KenZ71 Solar Expert Posts: 58 ✭✭
    Re: Interesting observations from a newbie

    I have not made the detailed observations like yours. However my system just went live Monday, since then we seem to have a lot more clouds.

    I tell myself more clouds means less need for Air Conditioning.
  • Alaska Man
    Alaska Man Solar Expert Posts: 252 ✭✭
    Re: Interesting observations from a newbie

    I set up my system this spring and ever since I did it has rained. LOL

    I'm not kidding, this is the rainiest summer in recorded history for Interior Alaska. When people complain about the rain I assure them this summer's weather is all my fault.

    I do find myself spending a lot of time in front of The Charge Controller when the sun does shine though. I even go out and play will the panels angle trying to squeeze the power output just a bit more.
  • CALLD
    CALLD Solar Expert Posts: 230 ✭✭
    Re: Interesting observations from a newbie

    Hahahaha yes I know the feeling all too well! Got my panels 7 weeks before the winter solstice, had to endure the longest 3 months ever waiting for the upturn in production, now it just seems to be either cloudy or hazy all the time! Considered getting a wind turbine to help but I can be damn sure if I do the wind will never blow in the windy city again, ever!