Solar panels output

I’m trying to determine if my solar panels are working correctly. I have 12 Canadian Solar 250 watt panels, in a series/parallel configuration. Two paralleled sets with 6 panels in each string.
The highest output I’ve seen so far has been around 1300 watts. Theoretically I should be around 3000 watts under perfect conditions?
Now these are used panels and I’m not sure how old they are. Should I be satisfied with 1300 out of 3000 watts?
I haven’t made any effort to maximize the angle for the panels, and I have no test equipment to test individual output. They are just leaning up against my backyard fence, facing south.

Can't answer.

What is your battery voltage?
There is zero shade?
What is your solar charger?
Are all panels in a single string facing the same direction?
Have you confirmed the numbers at high noon with the charger in bulk mode?

I'm seeing panels all at slightly different orientations. This means that all six panels in a string will perform no better than the worst performing panel.

sunshine_eggo said:

Can't answer.

What is your battery voltage?
There is zero shade?
What is your solar charger?
Are all panels in a single string facing the same direction?
Have you confirmed the numbers at high noon with the charger in bulk mode?

I'm seeing panels all at slightly different orientations. This means that all six panels in a string will perform no better than the worst performing panel.

Click to expand...

Battery voltage is 48v 16 272ah cells in series.
At the max output, yes zero shade
Inverter is an Growatt SPF 3000TL LVM-ES
You can see the panels in my two pictures. 6 panels in a single string
Yes, at high noon. Inverter set to Solar first
Yes it’s not possible to have all of the panels aligned exactly the same as you can see in the pictures. But they are close. The fence is in a straight line

The picture shows tree limb shading and the panels are at different angles.

That little bit of shading is a big deal. Angle and orientation is 2nd.

Given the picture, half production is not a surprise. I recommend some tree trimming and a mount of some sort to get them all in a perfect line with adjustable angle. You will be much happier.

seneysolar said:

The picture shows tree limb shading and the panels are at different angles.

That little bit of shading is a big deal. Angle and orientation is 2nd.

Given the picture, half production is not a surprise. I recommend some tree trimming and a mount of some sort to get them all in a perfect line with adjustable angle. You will be much happier.

Click to expand...

I thought the same, but I suspect that's a reflection of branches above the panels, not shadows.

Dave (Boog) said:

Battery voltage is 48v 16 272ah cells in series.
At the max output, yes zero shade
Inverter is an Growatt SPF 3000TL LVM-ES

Click to expand...

80A MPPT, so should be good for about 4000W

Dave (Boog) said:

You can see the panels in my two pictures. 6 panels in a single string
Yes, at high noon. Inverter set to Solar first

Click to expand...

Have you added > 2000W of loads @ high noon to ensure it doesn't influence incoming PV?

Dave (Boog) said:

Yes it’s not possible to have all of the panels aligned exactly the same as you can see in the pictures.

Click to expand...

It is entirely possible. You just don't want to do a proper mount.

Dave (Boog) said:

But they are close. The fence is in a straight line

Click to expand...

I think it's time to get a multimeter to check Voc of each string and clamp DC ammeter to confirm Isc of each string.

High voltage, so be very careful.

sunshine_eggo said:

I thought the same, but I suspect that's a reflection of branches above the panels, not shadows.



80A MPPT, so should be good for about 4000W



Have you added > 2000W of loads @ high noon to ensure it doesn't influence incoming PV?



It is entirely possible. You just don't want to do a proper mount.



I think it's time to get a multimeter to check Voc of each string and clamp DC ammeter to confirm Isc of each string.

High voltage, so be very careful.

Click to expand...

Yes, I had a 2800 watt load running.
I will try your suggestions. Yes I know it’s over 180 volts at like 16 amps. I also just ordered a Solar test meter. When I get it, I will check each panel individually.
I want to do a proper mount. But I’m waiting for HOA approval to mount them on my roof. This was just temporary to test my DIY battery and Growatt inverter.

In your second image I note grass or weeds along the bottom edge of your solar panels. It does not take much shadow to cause a big drop off in wattage output. The slight different angle of each panel is not a big concern but any tree throwing shade on them is. Looks like you have a heavily wooded area which will mean careful placement to maximize production and perhaps tree removal.

seneysolar said:

The picture shows tree limb shading and the panels are at different angles.

That little bit of shading is a big deal. Angle and orientation is 2nd.

Given the picture, half production is not a surprise. I recommend some tree trimming and a mount of some sort to get them all in a perfect line with adjustable angle. You will be much happier.

Click to expand...

Actually the picture was taken around 2 pm. The maximum output was at noon and there was no shading. I’m waiting for HOA permission to roof mount them. They do not allow a permanent ground mount. This was just for initial testing.

Mattb4 said:

In your second image I note grass or weeds along the bottom edge of your solar panels. It does not take much shadow to cause a big drop off in wattage output. The slight different angle of each panel is not a big concern but any tree throwing shade on them is. Looks like you have a heavily wooded area which will mean careful placement to maximize production and perhaps tree removal.

Click to expand...

Thanks, I’ll look into that