Solar power output vs weather

[Bud Martin]

I have All in one 12V 1000W system.
I am in Bay area, north of S.F.
Panels: 4 used SUNPOWER SPR230 connected in parallel.
Loads: TV, Laptop, lights, air cleaner total about 350W
Power usage: 3KWH a day.
I have been tracking the amout of power I am getting and start seeing the pattern, I see that on a cold overcast days with cloud moving in and out but no clear sun lights my power can go up to over 800W, on a nice clear day and a little warm, I will get about 600W.
So it looks like I get so much more power, 35%, more on the cold day, I did not expect to see that much power gain.
Anybody has been keeping track of your system to see what you get?

 

[Jim Burrow]

Hi Bud, I live in Livermore and also tracking my Solar output with 60-watt, 123-watts, and 250-watt loads and also notice that I get good output on cold days. I'm also surprised at how much solar output I get on our cloudy days.

Although my solar wattage (hence current) is constantly changing from moment to moment, the Solar output Voltage remains around 65 to 70 volts. My 300-watt panels are rated at 39-volts OCV but a typical voltage of 37-volts according to the spect sheet.

My system is managed by the MTTP all-in-one pip-2424lv-msd controller. The system is on my workbench at the moment for testing and the panels are lying on the ground on sawhorses. I won't be installing my (6) 300-watt panels on my carport rough until May because I'm waiting for the tree man to cut back some tree branches that could fall on the carport rough. At the moment I'm re-wiring my house Breaker box in order to tie in the controller between the house and the utility company meter.

I'm getting tired of PG&E turning off our power all the time due to winds and power always going off in my neighborhood once or twice a month during our summer months and heavy loads on the main circuit breaker that supports 6 houses. (B.S. I know, but there is nothing I can do about it) So my system will run off of Solar and battery with PG&E kicking in when there isn't enough solar or battery to support my house. And if at night and the battery runs down and the Utility power is still off, I have the ability to connect my gas generator to the system.

At night, I'm only pulling 165-watts in the house. and during the days could get up to 650-watts at any one time. This is without counting the appliances which will not be connected to the solar system but will always be connected to PG&E. But the refrigerator will be connected to the solar system as part of the house's normal usage.

 

[Bud Martin]

Hi Jim,
My is PIP-1012LV-MK.
I was looking into buying a small generator from COSTCO last year to prepare myself this time for rolling blackout which I lost power for about 5 days, then I went on Youtube to see the review about the generator I was looking at, I then stumble onto Will vidoes so I start watching them, study and do more research and try to undertand about solar system (I design power products for the company in Petaluma fro abou 25 years so I alrerady have background on electronics already but not familair about solar system even though Enphase is right down the road from me), so I got hook and decide on all in one system (MPP Solar) that Will made the video on.
I am happy that I am able to get my system running and it saves me about $25 a month which is not much but at least now I will have power to keep my fridge, lights, and computer running if black out happens again (I have gas stove and gas water heater so I can still cook and have hot shower without power), to me the most important is the knowledge I gain from Will vidoes and from this forum, it is woth a lot more than $25 a month.
The PV Voltage is 37.20Vdc when I get 820W, at 35.30Vdc is 600W.
SPR230 has Voc of 48.70Vdc, Vmp of 41.00Vdc, Imp of 5.61A.

 

[Jim Burrow]

Interesting Bud, I did the same thing and bought a generator from Costco then ran across Will's videos and watched every one of them. Although I've been retired for about 25 years from my profession as an electronic Engineer and on the rusty side, with this forum, I have learned a lot about Solar.

My hang-up now is trying to isolate part of the house that will be running on Solar and the other part on the Utility grid. The issue is that whoever build these manufactured homes (I sold my home and downsized 8 years ago into a mobile park) tied the white (neutral) wires to the grounding bar and to my breaker box.

To my understanding that is a big No-No, but was common practice many years ago (my place is 15 years old) to full the inspectors that the home was wired correctly.

I need to separate the two halves of the wiring as it is dangerous (at least to my understanding)d to have two independent AC sources connected to the same neutral return wire.

Anyway, that is what I'm presently working on. It would be nice to get in touch with a licensed electrician to make sure I do the job correctly, but they cost an arm and a leg. Being retired, I just can't afford one.