I had solar installed late summer - 8KW system.

Back then I was getting about >6KW peak generation. These days, it's about 5Kw peak.

The sun, I would guess, is about the same at peak times. I would have guessed that summer total generation is > winter generation because of longer daylight hours.

But I'm also getting less generated at "high noon" (actually, peak generation for me seems to be about 1:00 or 2:00).

Expected? Why? For 8KW system, what peak should I expect for summer and winter?

You’re west coast right? Is there a bunch of ash on the panels from fire season?

Panel generation is affected by angle of sun. Less perpendicular, less generation.

https://www.mpptsolar.com/en/b...or-solar-panels.html

Konata, your winter power will be less than summer because of solar declination. The solar rays are coming in at a lower angle during the winter, so even the over the same number of hours, you would be seeing less peak generation.


The sun at high noon in the winter is still lower on the horizon than high noon during the summer.

Got it. Expected behavior. Thanks. Just wanted to make sure nothing wrong.

It was filthy from ash. A rain cleaned it up noticeably but output didn’t seem affected.

quote:

Originally posted by Voshterkoff:
Is there a bunch of ash on the panels from fire season?

Get somebody to haul your ashes. :{

I try to spray mine down with the hose anytime there is dust, etc. After a rain, tree crap, pollen, whatever. It’d be better if I got on the roof with some sort of mop but I’m getting old enough now where I’m not doing that unless it gets bad. Just a hose with a spray nozzle from ground level.

Winter yeah, expected.

Can you tilt your panels? I tilted my panels back on the 15th of september. Also, your panels will be more efficient in the winter as the panels stay cooler. Heat in the summer degrades efficiency even though the sun is higher in the sky for longer.

I'd be interested to see if this is seasonal or if they degrade over time and how quickly.

Mine always amaze me, 4 panels at 230 watts each. Keep my six solar batteries charged. They supply 2 big chest freezers, but as long as there is less than 6" of snow on them, I'm good.

This is interesting,

We are seeing more of these around my area

I am
Not a solar expert but did have some questions on it, if I can ask a couple of questions

if the questions are out of line let me know and I'll apologize.

If you bought an 8kw system did the installer indicate when you would achieve 8kw?

When you are discussing your system for purchase do they give any monthly kW output projections per time of year.

When discussing payback do they use the 8kw or say 6 kW which appears to be the average for the calculations?

Thanks

Just spraying the panel will remove most of the gunk....but like windows, it takes physically wiping the panel to remove gunk.

Fuller brush Co.advertised a spray that was supposed to clean windows spot free no rinse.twenty bucks Worth a try!

quote:

Originally posted by RC:
This is interesting,

We are seeing more of these around my area

I am
Not a solar expert but did have some questions on it, if I can ask a couple of questions

if the questions are out of line let me know and I'll apologize.

1) If you bought an 8kw system did the installer indicate when you would achieve 8kw?

2) When you are discussing your system for purchase do they give any monthly kW output projections per time of year.

3) When discussing payback do they use the 8kw or say 6 kW which appears to be the average for the calculations?

Thanks

For me, responses from other may be different.
1) No, but they gave specs for the panels (efficiency rating, etc). They may have projected something but I was going to check empirically; in any case, the measurements are based on whatever the system reports anyway, I have no way to verify how accurate the system reported numbers are.

2) No; I think they may have provide projected annual output but I didn't pay attention. I made some estimates myself based on panel specs, efficiency, zone and research of the webz (and what others were reporting for their systems).

3) Not sure it really matters - either way I'm producing more than I need (currently). And I don't really get any benefit for over production. I bought oversupply to mitigate forward looking risks (increases in electricity rates, using my AC more, possible EV car purchase, etc).

quote:

Originally posted by konata88:
I had solar installed late summer - 8KW system.

Back then I was getting about >6KW peak generation. These days, it's about 5Kw peak.

The sun, I would guess, is about the same at peak times. I would have guessed that summer total generation is > winter generation because of longer daylight hours.

But I'm also getting less generated at "high noon" (actually, peak generation for me seems to be about 1:00 or 2:00).

Expected? Why? For 8KW system, what peak should I expect for summer and winter?

Been living offgrid for 15yrs. Installed everything myself, installed/monitor other offgrid systems as well. It's the sun/panel angle lowering your output. Our panels are on a ground mount rack, change the angle a few times a year. Simply put a framing square on a panel at solar noon for my rack orientation, use the perpendicular shadow to adjust. Have never cleaned the dust off, do sweep off snow every time it snows as the snow will greatly reduce output.

quote:

Originally posted by Sigolicious:
Can you tilt your panels? I tilted my panels back on the 15th of september. Also, your panels will be more efficient in the winter as the panels stay cooler. Heat in the summer degrades efficiency even though the sun is higher in the sky for longer.

Interesting, that's the exact opposite of most specification sheets I'd seen for panels. They typically rate these at 80F,and expect roughly half the output as temperature drops to 40F. That was a decade ago when I last looked, though, so maybe the technology is better now?