Solar power ? Suddenly losing lots of power, why?

[kimanjome]

Hi. Really puzzled over this.

Last year this time I was generating 12 or 13 kw every sunny day, and about 7 or 8 on cloudy days.

This year I installed a variable speed pool pump and a mini split a/c, inverter, eco type. The mini split I have been running at night, about 9 hours, temp 25.  Looked over the past weeks records and noticed I am in the negatives, roughly using 3 kwh more than what I'm producing. That is what I expected.

However, these past 36 hours I have lost 20 kwh, and that with totally clear skies!  I can't figure it out.

Also, I just went and checked my meter (again) and I am showing a 1 kwh gain over 4 hours, which is NOT normal.  I should have produced 3-4 kwh, and the meter should reflect this.

Nothing has changed, except that the power in San Antonio has been on/off, on/off, on/off, constantly. Would that have anything to do with it and if so, why? What else should I be looking at?

 

 

 

[Go Solar]

Would suggest all of these:

1 - check your CFE meter readings (both #'s, "use" and "sent") both AM and PM to see what is happening both in the day, and at night, net-use or credit wise.

2 - check your inverter(s) daily production figures on the display or online, and also the real time wattage figures in good sun conditions against what you know is the norm (sounds like you have a 2.5 kW size system, approx, so 2000 watts AC or so should be being produced in good sun)

3 - have your system checked by your installer or other qualified provider.

Yes, the grid power issues could have caused a partial malfunction, hence # 3.

 

 

[Mainecoons]

Also make sure your panels aren't covered with a heavy layer of dust from the dirty air this time of year.  I usually have to wash mine twice before the rains start but this year we got that lovely rain earlier this month.

Go Solar looks like our microinverter system lost a couple kWh today due to the fluctuations but it always comes right back on.  These new microinverters you put in really seem to work well.  Increased power production about 5% too.

We're on the edge of some really heavy activity tonight, at least stirring up some nice breezes.  Rain soon?  Maybe time for the annual guess start of rainy season thread. 

 

[Tingting]

I sent you a pm.

[snowyco]

If you have a single central inverter, then dust,  bird poo & bat poo splatters cut our solar systems output by between 10% - 30%, especially during the morning & afternoon.  Micro-inverters have that advantage over central inverters,  that bird poo on a single panel affects just that one panel's~inverter's output,  while central inverters have their panels in a string, so 1 blob of bird poo cuts power on the whole string. ...  Just 2 weeks ago,  I noticed our central inverter system was only putting out 1,360 watts, one morning when it should have been at 1,900W.  I scraped off the dried bird poo with a razor blade,  and the system output jumped to 1930W. ... The bird poo was on a single 250W panel,  but it cut the system output by 540W.

If your panels are clean,   then ... Oxidized-lightly corroded junctions inside the electrical connectors has also caused drops in friends' central-inverter systems, as central inverters have the panels in a string, so one dirty internal junction affects the power flow for all panels.   We found that the normal 'crimped' joints inside each electrical coupler occassionally get a little corrosion after a few years (corrosion happening where the wire is crimped into the junction) ... Instead we solder all the joints-junctions where the wires enter the black MC4 electrical solar connectors..

 

[kimanjome]

Thanks, everyone. Had "a solar guy" go into the roof and sure enough, the panels are covered with dust and lots of bird poo. I hadn't considered this, as the guys who just finished applying impermbilizante on the roof said they were going to clean the panels. Well.

"The solar guy"  checked connections, everything okay. He also noted the inverter readings and the CFE meter, and will be returning in one week to note the numbers for a discrepancy. Meanwhile, will have the Jardinero wipe down the panels, I was told by The Solar Guy that is usually who does it.