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That's not a resource, that's a guy talking, and it's also out of context speaking only to generalities.

Here's what my charge controller looked like this morning:

1601499523021.png

The panels were at 100V before current was even produced. This was during civil twilight while the sun was below the horizon. Even less light than is available during a "bright" cloudy day, my 3kW array produces 800-1000W. If it's a dark gray stormy day, I'm lucky to get 300W.

Once it found the MPPT voltage, the 3kW array was only producing 200W - less than it does on a very cloudy day.

Data be damned. Do what you want assuming you even both getting off grid. Good luck.
 
That's not a resource, that's a guy talking, and it's also out of context speaking only to generalities.

Here's what my charge controller looked like this morning:

View attachment 24038

The panels were at 100V before current was even produced. This was during civil twilight while the sun was below the horizon. Even less light than is available during a "bright" cloudy day, my 3kW array produces 800-1000W. If it's a dark gray stormy day, I'm lucky to get 300W.

Once it found the MPPT voltage, the 3kW array was only producing 200W - less than it does on a very cloudy day.

Data be damned. Do what you want assuming you even both getting off grid. Good luck.

That sounds pretty good to me. So on a typical cloudy day you can produce up to 1kwh over the course of the whole day? Or do you mean your panels are sustaining 1000W output all day long?

What's your array setup like? Series of 2? Panel rated watts? I'm still too green to really grasp your point here. Are you telling me that the 3s vs. 2s setup is essentially a non-issue?

Oh, I also wanted to ask you why you prefer Victron over some of the cheaper stuff on the market nowadays like the Growatt 3-in-1s? Is it worth the money in your opinion?
 
No, my peak power is 800-1000W, so my total harvest is about 4-5kWh.

My 330W panels are very similar with nearly identical voltages (72 cell panels). I chose 3S6P (currently only 3S3P deployed) to fit the entire array on a single Victron 150/100, but I'm too close to the 150V limit to deal with cold weather spikes, so I replaced it with a 250/100 because I'm too lazy to rewire it, and I either needed to get a second controller or replace it. I opted for the 15 minute solution that didn't require me rewiring everything.

~78 Vmp will still be more than adequate for efficient MPPT operation for a 48V battery.

I prefer Victron because I want good surge capability, features, reliability and support. MPP Solar and Growatt are Chinese made "light duty" high frequency units (most of them anyway) with poor surge and no more than 10 years of global service history.

Victron, Outback, Midnite Solar, Magnum, Xantrax and Schneider are the units you buy with the expectation of a lifetime of service.

MPP Solar and Growatt are the ones you buy HOPING for a lifetime of service.

I would put Sigineer/Aims, etc. somewhere in the middle.
 
No, my peak power is 800-1000W, so my total harvest is about 4-5kWh.

My 330W panels are very similar with nearly identical voltages (72 cell panels). I chose 3S6P (currently only 3S3P deployed) to fit the entire array on a single Victron 150/100, but I'm too close to the 150V limit to deal with cold weather spikes, so I replaced it with a 250/100 because I'm too lazy to rewire it, and I either needed to get a second controller or replace it. I opted for the 15 minute solution that didn't require me rewiring everything.

~78 Vmp will still be more than adequate for efficient MPPT operation for a 48V battery.

I prefer Victron because I want good surge capability, features, reliability and support. MPP Solar and Growatt are Chinese made "light duty" high frequency units (most of them anyway) with poor surge and no more than 10 years of global service history.

Victron, Outback, Midnite Solar, Magnum, Xantrax and Schneider are the units you buy with the expectation of a lifetime of service.

MPP Solar and Growatt are the ones you buy HOPING for a lifetime of service.

I would put Sigineer/Aims, etc. somewhere in the middle.

You're producing 4-5kwh on a cloudy day with 2,970W of panels connected?! Amazing.
 
It depends on the degree of clouding. I can have a cloudy day, 100% coverage, but not particularly thick and still get good output; but I can also get really heavy clouding for days that sees a 2kW array limping along at 100W.
 
You're producing 4-5kwh on a cloudy day with 2,970W of panels connected?! Amazing.

Maybe, but when it's 20kWh+ for a cloudless summer day, it's not that impressive.

gnubie described it, and I've tried to characterize it as well... This is for a "bright" day where you have 100% cloud cover, but it's thick enough that you can't tell where the sun is in the sky. Those dark gray days where it looks like it may rain any second?... 100W is a damn fine harvest.
 
My array DC rating is 4,800 watts (16 x 300 watt panels). During the bad fires here with all the smoke in the sky, I had a few of my worst production days ever. But thanks to being in So Cal (long sun day), I still managed to make 8 KWH's while not even being able to cast a shadow all day. The diffuse light in the sky actually made power to later in the day before the inverters finally quit about 6:45 pm. Sept. 10 my peak power never topper 1,600 watts, where it hit 3,200 watts today. Last year when I still had the Palm trees killing the evening production of 8 panels, those panels would actually perform much closer to the unshaded ones in the sky was hazy. The diffuse light got behind the palm trees when when the sky is clear, they were in a solid dark shadow. So if the clouds cut the other panel's output in half, these lost almost nothing. Yes, the non shaded ones still made more power, but it was interesting to see that the known shaded panels not lose power when the sky was grey vs sunny.
 
Victron, Outback, Midnite Solar, Magnum, Xantrax and Schneider are the units you buy with the expectation of a lifetime of service.

SMA?

Come on, make me feel good about my purchases! :)

(I now have 68 kW of Sunny Island, 97.5 kW of Sunny Boy, and 55 kW of panels. Still working on getting them all deployed.
Oh, and 20 kWh of AGM battery.)
 
SMA?

Come on, make me feel good about my purchases! :)

(I now have 68 kW of Sunny Island, 97.5 kW of Sunny Boy, and 55 kW of panels. Still working on getting them all deployed.
Oh, and 20 kWh of AGM battery.)

I should have qualified it with off-grid... I don't know squat about grid tie.
 
I should have qualified it with off-grid... I don't know squat about grid tie.

Is this far enough off-grid for you?


They've offered battery inverters as small as 2 kW up to multiple clusters totaling 100 kW.
A bit of DC coupling for a while, but mostly AC coupled, which can be up to 2x the battery inverter.
So 100 kW + 200 kW = 300 kW available while the sun shines.
The key off-grid feature is frequency shift to curtail AC power from inverters to match load.
Also supports wind/hydro and diesel generators.
Their "Sunny Boy" AC coupled inverters used to have settings for use with turbines, and there were extra boxes to manage those devices. But the newer models only have MPPT for PV
 
SMA is certainly a high quality company with a long history in solar power.
 
Maybe, but when it's 20kWh+ for a cloudless summer day, it's not that impressive.

gnubie described it, and I've tried to characterize it as well... This is for a "bright" day where you have 100% cloud cover, but it's thick enough that you can't tell where the sun is in the sky. Those dark gray days where it looks like it may rain any second?... 100W is a damn fine harvest.

And I'm assuming there's a huge difference for you between a cloudy winter day and a cloudy summer day.
 
The density of the clouds makes a big difference. When it is light out, but you still can't see any shadows, I still make fair power, about half of a clear sky, but it makes it all day. Total harvest can still hit 10-15 KWH instead of the usual 22 KWH or so. In perfect sunny, but cool, and no clouds in spring I hit 31 KWH's for my best day yet. So less than half happens on those overcast but still bright days.

When the clouds are heavy, and you add in the wildfire smoke, my worst day yet has still hit 5 KWH's since I got rid of the palm tress that blocked several panels. That's about 1/6 of my best productions, 1/4 of a "normal" day. Going back over more than a year, I did find a few days that dipped below 4 KWH's, but not only was that with the trees in the way, it also was rainy and heavy clouds.

Here is the best weather event I could find, from April 12 this year.
Apr12-2020.PNG
The day before is the line over the top, making near my best power at 30.6 KWH, with all of the inverters clipping for 2 hours at 3,850 watts. And then the next day was at 6.5 KWH total. The power only peaked to 1,400 watts when the sun poked through the clouds for a few minutes.

As good as solar power can be, it is certainly at the mercy of the weather. I am in a very good location. These events are rare. Take a place like Seattle and this is more the normal than the odd exception.
 
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