diy solar

diy solar

Different but similar panels

7

73powerstroke

Solar Enthusiast
Joined
Jun 17, 2022
Messages
898
Location
Arizona
I'm not sure if I should try to re arrange these panels. But what I have is 4 trina 240w panels and 5 Gloria 225W panels in 3s3p on my hvlv2424. Normally I would need 12 of the 240w trinas to realize the 2000w 80amp input .
These panels are both physically the same size. Each Gloria 225w has different but similar specs. Some say 229w some 227w. With different amps and voc
9 panels under heavy load (1.8kw) made 1.6kw earlier today but I think I might be able to arrange these different where the smaller panels don't drag everything down. I have another 3 more Gloria's for my 12 I would normally need to make the 2kw. I think im losing 30w per panel. The trinas usually do 180w but I think the others are 155w
So we have
Trina voc 37.2 vs 37.05 Gloria
Vpmax 30.4 vs 28.78
Isc. 8.37 vs 8.57
Ipm 7.89 vs 7.92

20220810_135632.jpg20220810_135604.jpg
 
Numbers-wise, those would do better in series than parallel, but the odd number in the array complicates it.

I would create an interleaved array, 3S3P as follows:

1=5 panels of one type
2=4 panels of one type

1 2 1
2 1 2
1 2 1

S1 and S3 would have identical Vmp, S2 would be a little lower.

I would expect a ~5-10% loss AT BEST from this configuration.
 
sunshine_eggo said:
Numbers-wise, those would do better in series than parallel, but the odd number in the array complicates it.

I would create an interleaved array, 3S3P as follows:

1=5 panels of one type
2=4 panels of one type

1 2 1
2 1 2
1 2 1

S1 and S3 would have identical Vmp, S2 would be a little lower.

I would expect a ~5-10% loss AT BEST from this configuration.
Click to expand...
I have 8 of the 225w panels. And 4 of the 240w. I don't need to do 3s I can do 2s but some people think the hvlv2424 does better at 70v or higher so that was why I did 3s
 
1=8X 225W
2=4X 240W

Ah, so 3S3P or 3S4P would work

3S3P:
String#
1 2 3
1 1 1
1 1 1
2 2 2

3S4P:
String#
1 2 3 4
1 1 1 1
1 1 1 1
2 2 2 2

There should theoretically be no mismatch of any kind beyond variations in panel performance.
 
I added the last 3 225w panels. I'm now 3s4p.kinda muddy mucky in backyard so I want able to switch stuff like I wanted to
 
NOCT rating is about 75% that of STC rating. In this kind of heat with hella-hot cells, that's really all you should expect at high noon with perfect tilt (around 15°) and due South orientation.

If all those are used panels, I would knock another 10-20% off that number as well.
 
sunshine_eggo said:
NOCT rating is about 75% that of STC rating. In this kind of heat with hella-hot cells, that's really all you should expect at high noon with perfect tilt (around 15°) and due South orientation.

If all those are used panels, I would knock another 10-20% off that number as well.
Click to expand...
All used santan panels. They sold out the older browning Gloria 225W panels but they were $29.50 each. I WOULD HAVE GOTTEN MORE .
I have 2 that are so dark they look like monocrystalline panels and have odd squares in center of cells. One has a snail trail. ( WORK SAME AS REST)But the other 6 look just like trinas without the cracked backs. I think output is about 155-175 on those and 180 on up for the trinas.
We get storms daily so it's hard to get a day of productive work
 
sunshine_eggo said:
At 6500', mild temps (75°F) and cloud edge effects...

View attachment 106453

I'm getting a little above rated (2970W). The peak is 3431W.

Normally I'd be getting around 2700W.
Click to expand...
What software is that your using. I like it. I want to find a way to monitor my epevers and mpp solar hv lv2424 together or something. The mpp solar software is terrible. And I've not tried anything yet for epevers. I have a usb cable for those
Edit victron?
 
Voltage vs. Amperage considerations when combining different panels into a single MPPT input...
In a string of panels, the maximum amperage you can get will be that of the lowest rated amperage (or actual output) panel in the same string. Voltage doesn't matter, only amperage. If you can keep the string of the same specs/output that would help prevent derating waste of the stronger ones' outputs.
No problem combining different capacities of strings into a single MPPT input as long as the nominal and working voltages (amperage doesn't matter here) of each string is the same, and you have each string feeding through a blocking diode. If your MPPT has multiple array inputs that would be even better since you'd be maximizing the different output curves for the different spec panels. They will always be different.
Another point of interest for you is that used panels always derate differently from one to the next; it's just their nature. If you can match panels up in a string to their actual working MPPT amperage output you'll minimize opportunity loss in the string. Matching amperage within the strings is the first priority, the second is matching up working MPPT actual voltage output between strings themselves. There again, the closer the strings are in output voltage feeding to a common MPPT input, the less the opportunity loss. The downside in this pursuit of maximum efficiency is the amount of tedious work it takes evaluating each panel. I use a small MPPT on a 12v battery held below 13v and connect each panel individually one at a time to record their metrics. Accuracy requires ensuring each panel is tested clean and aligned perpendicularly perfect to incoming sun, and you can use a solar irradiance meter to record your baseline irradiation to compensate for any variation there. It would take me two or three days to evaluate 12 panels since I'd want it done only between 12:00-1:00pm with fully clear skies, so with some hustle maybe just one weekend.
 
JBertok said:
Voltage vs. Amperage considerations when combining different panels into a single MPPT input...
In a string of panels, the maximum amperage you can get will be that of the lowest rated amperage (or actual output) panel in the same string. Voltage doesn't matter, only amperage. If you can keep the string of the same specs/output that would help prevent derating waste of the stronger ones' outputs.
No problem combining different capacities of strings into a single MPPT input as long as the nominal and working voltages (amperage doesn't matter here) of each string is the same, and you have each string feeding through a blocking diode. If your MPPT has multiple array inputs that would be even better since you'd be maximizing the different output curves for the different spec panels. They will always be different.
Another point of interest for you is that used panels always derate differently from one to the next; it's just their nature. If you can match panels up in a string to their actual working MPPT amperage output you'll minimize opportunity loss in the string. Matching amperage within the strings is the first priority, the second is matching up working MPPT actual voltage output between strings themselves. There again, the closer the strings are in output voltage feeding to a common MPPT input, the less the opportunity loss. The downside in this pursuit of maximum efficiency is the amount of tedious work it takes evaluating each panel. I use a small MPPT on a 12v battery held below 13v and connect each panel individually one at a time to record their metrics. Accuracy requires ensuring each panel is tested clean and aligned perpendicularly perfect to incoming sun, and you can use a solar irradiance meter to record your baseline irradiation to compensate for any variation there. It would take me two or three days to evaluate 12 panels since I'd want it done only between 12:00-1:00pm with fully clear skies, so with some hustle maybe just one weekend.
Click to expand...

thank you for this wall of text.

73powerstroke said:
What one are you using?
Click to expand...

There is no "one" Victron. :) It's a separate component for each.

Described in my "About" page:

diysolarforum.com

sunshine_eggo

diysolarforum.com diysolarforum.com
 
JBertok said:
Voltage vs. Amperage considerations when combining different panels into a single MPPT input...
In a string of panels, the maximum amperage you can get will be that of the lowest rated amperage (or actual output) panel in the same string. Voltage doesn't matter, only amperage. If you can keep the string of the same specs/output that would help prevent derating waste of the stronger ones' outputs.
No problem combining different capacities of strings into a single MPPT input as long as the nominal and working voltages (amperage doesn't matter here) of each string is the same, and you have each string feeding through a blocking diode. If your MPPT has multiple array inputs that would be even better since you'd be maximizing the different output curves for the different spec panels. They will always be different.
Another point of interest for you is that used panels always derate differently from one to the next; it's just their nature. If you can match panels up in a string to their actual working MPPT amperage output you'll minimize opportunity loss in the string. Matching amperage within the strings is the first priority, the second is matching up working MPPT actual voltage output between strings themselves. There again, the closer the strings are in output voltage feeding to a common MPPT input, the less the opportunity loss. The downside in this pursuit of maximum efficiency is the amount of tedious work it takes evaluating each panel. I use a small MPPT on a 12v battery held below 13v and connect each panel individually one at a time to record their metrics. Accuracy requires ensuring each panel is tested clean and aligned perpendicularly perfect to incoming sun, and you can use a solar irradiance meter to record your baseline irradiation to compensate for any variation there. It would take me two or three days to evaluate 12 panels since I'd want it done only between 12:00-1:00pm with fully clear skies, so with some hustle maybe just one weekend.
Click to expand...
Yeah I have tested a few of them on a smaller 12v system but they are all close enough to not worry about it.
 
After a tree murdered some of my solar panels I replaced the 7 remaining 240 watt solar panels with Twelve 270 watt panels that I was able to purchase locally for less than the shipping for the same replacements. This solar array is on my travel trailer and in the process I put 3 of the old panels on the slide out roof and connected them to the system. In my case the difference in max power voltage was minimal between the 270 watt panels and the 240 watt panels but the result was that in good sun the 240 watt panels output almost nothing when paralleled with the 270 watt panels. If connected separate from the 270s they output normally. I suspect that the higher power point voltage of the 270 watt panel is just high enough to cause the 240 watt panels to produce almost nothing.
 
Bobert said:
After a tree murdered some of my solar panels I replaced the 7 remaining 240 watt solar panels with Twelve 270 watt panels that I was able to purchase locally for less than the shipping for the same replacements. This solar array is on my travel trailer and in the process I put 3 of the old panels on the slide out roof and connected them to the system. In my case the difference in max power voltage was minimal between the 270 watt panels and the 240 watt panels but the result was that in good sun the 240 watt panels output almost nothing when paralleled with the 270 watt panels. If connected separate from the 270s they output normally. I suspect that the higher power point voltage of the 270 watt panel is just high enough to cause the 240 watt panels to produce almost nothing.
Click to expand...
Interesting. So in series they were fine?
 
73powerstroke said:
Interesting. So in series they were fine?
Click to expand...
My charge controller is such that in order for it to operate properly I must have panels of this voltage three in Series and then parallel together as many strings as I have. So three of the 240 W panels by themselves produce expected output. And any number of strings of three 270 W panels produce expected output But when the 240 watt panels are combined with the 270 watt panels 240 watt panels contribute virtually nothing. They do seem to contribute in low light conditions this is why I suspect that it is a PowerPoint issue. Perhaps PowerPoint is not considered in the mixing of panels very often. From now on if I ever have to mix panels I am going to try them separately to see if I am losing a tremendous amount of wattage.
 
Bobert said:
My charge controller is such that in order for it to operate properly I must have panels of this voltage three in Series and then parallel together as many strings as I have. So three of the 240 W panels by themselves produce expected output. And any number of strings of three 270 W panels produce expected output But when the 240 watt panels are combined with the 270 watt panels 240 watt panels contribute virtually nothing. They do seem to contribute in low light conditions this is why I suspect that it is a PowerPoint issue. Perhaps PowerPoint is not considered in the mixing of panels very often. From now on if I ever have to mix panels I am going to try them separately to see if I am losing a tremendous amount of wattage.
Click to expand...
Yep. I suspect I'm losing some .however I realized that I have 8 240w panels on a separate cc. So I will switch those 8 for these 225W. Then I'll have 12 240w trinas on the hvlv2424 and no mix match. 1400 was not terribly bad for the mix.
Uh, yeah actually I should be at around 2160 so lost some there. But these 240s do 180w. The 225s do 155 to 170 or so.
So bare minimum 1860=12x155w.
So I'll swap these. I can't get more of these 225w panels and I didn't want to buy too many incase they gave me crappy ones
 
You must log in or register to reply here.
Back
Top