Mix and match Panels.

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NoraBatty
Posts: 147
Joined: Sat Mar 23, 2024 10:40 am

Mix and match Panels.

#1

Post by NoraBatty »

I dread to ask.
As i think i already know the answer. :head-bang:

I have a string of 3x CS6R-395 MS
395W that are not reaching starting voltage.

The "remedial" works started yesterday.
They are adding a panel. Ive just had a look at the new panel and it is It is a canadian solar CS6R -430T.
430W

Clearly they are different panels, but will they work together?
Going on the same string on a solis s6 gr13pk.
Second string is 4x 395 panels but is being left alone as working fine


Image

Image
2.7kw Canadian solar. roof. 3kw solis G98 mcs
12kw midea ASHP
200l hot water
3152W RE, Whitelaw Brae
Octopus agile/outgoing fixed 15p

Planned;
Hybrid system
43kwh eve batteries, 3x16 280A
6-8+kw solar, DC connected.
Ken
Posts: 517
Joined: Mon Jul 26, 2021 10:07 am

Re: Mix and match Panels.

#2

Post by Ken »

There are normally variations in ACTUAL output of panels eg manufacturing tolerances, shading, seagull poo etc. So i dont think there is any difference.

I wonder if you have low voltage because they are not wired in series to boost the voltage. Thats the limit of my knowledge.
NoraBatty
Posts: 147
Joined: Sat Mar 23, 2024 10:40 am

Re: Mix and match Panels.

#3

Post by NoraBatty »

Hi Ken thanks,
The installers first denied the panels were any different, until i physically showed them, then stated it wouldnt be an issue. Hardly a confidence boosting dicussion from guys who have already messed up.
The new panel is higher amp, volt and watts than the existing, so my understanding is it may be clipped to the same as the existing panels. If it was smaller than the existing it would clip those to its own spec.
As long as it all works together and isnt leaving the panels worse off.

The panels are in series, but the original design was for 410w panels that had a higher voltage than the 395w that were then used. As a result the string was something silly like 10v under the starting voltage for the inverter. Hence the additional panel.
2.7kw Canadian solar. roof. 3kw solis G98 mcs
12kw midea ASHP
200l hot water
3152W RE, Whitelaw Brae
Octopus agile/outgoing fixed 15p

Planned;
Hybrid system
43kwh eve batteries, 3x16 280A
6-8+kw solar, DC connected.
User avatar
Stinsy
Posts: 2885
Joined: Wed Jun 02, 2021 1:09 pm

Re: Mix and match Panels.

#4

Post by Stinsy »

NoraBatty wrote: Thu Oct 24, 2024 10:10 am I dread to ask.
As i think i already know the answer. :head-bang:

I have a string of 3x CS6R-395 MS
395W that are not reaching starting voltage.

The "remedial" works started yesterday.
They are adding a panel. Ive just had a look at the new panel and it is It is a canadian solar CS6R -430T.
430W

Clearly they are different panels, but will they work together?
Going on the same string on a solis s6 gr13pk.
Second string is 4x 395 panels but is being left alone as working fine


Image

Image
There is no reason you cannot mix and match panels on the same string. The concepts to understand are the following:
  • Voltage is additive.
  • Current is whatever the weakest link.
So if you had 3x 400W 40V 10A panels and you added a 585W 45V 13A panel then you wouldn't get the full output of the new panel. You'd get the full 45V but only 10A from the new panel making it 450W. However your original 3x 400W panels would not be affected. On the other hand, if you added a 225W 30V 7.5A panel then the new panel would operate at its full power but your original panels would be limited to 7.5A turning those 400W panels into 300W panels. This would mean your array would produce more power without the additional panel than it would with it.

Long story short: in your example it is fine. That "430W" panel will only be able to achieve 413W but you shouldn't be too worried about that.
Last edited by Stinsy on Thu Oct 24, 2024 11:08 am, edited 4 times in total.
12x 340W JA Solar panels (4.08kWp)
3x 380W JA Solar panels (1.14kWp)
5x 2.4kWh Pylontech batteries (12kWh)
LuxPower inverter/charger

(Artist formally known as ******, well it should be obvious enough to those for whom such things are important.)
Countrypaul
Posts: 572
Joined: Sun Jul 18, 2021 11:50 am

Re: Mix and match Panels.

#5

Post by Countrypaul »

NoraBatty
Posts: 147
Joined: Sat Mar 23, 2024 10:40 am

Re: Mix and match Panels.

#6

Post by NoraBatty »

Stinsy wrote: Thu Oct 24, 2024 11:00 am There is no reason you cannot mix and match panels on the same string. The concepts to understand are the following:
  • Voltage is additive.
  • Current is whatever the weakest link.
So if you had 3x 400W 40V 10A panels and you added a 585W 45V 13A panel then you wouldn't get the full output of the new panel. You'd get the full 45V but only 10A from the new panel making it 450W. However your original 3x 400W panels would not be affected. On the other hand, if you added a 225W 30V 7.5A panel then the new panel would operate at its full power but your original panels would be limited to 7.5A turning those 400W panels into 300W panels. This would mean your array would produce more power without the additional panel than it would with it.

Long story short: in your example it is fine. That "430W" panel will only be able to achieve 413W but you shouldn't be too worried about that.
Thanks Stinsy.
I knew they would clip the new, but unsure if it would be okay for panel health etc.
Ita reassuring to know it will all be fine.
however ive just been told by the bossman iver the phone it would not be accepted under the existing mcs so is getting changed to be the same as existing, once they can source one
2.7kw Canadian solar. roof. 3kw solis G98 mcs
12kw midea ASHP
200l hot water
3152W RE, Whitelaw Brae
Octopus agile/outgoing fixed 15p

Planned;
Hybrid system
43kwh eve batteries, 3x16 280A
6-8+kw solar, DC connected.
NoraBatty
Posts: 147
Joined: Sat Mar 23, 2024 10:40 am

Re: Mix and match Panels.

#7

Post by NoraBatty »

Countrypaul wrote: Thu Oct 24, 2024 11:03 am This might reassure: https://solarpanelsvenue.com/mixing-solar-panels/
Very Helpful, thanks Paul
2.7kw Canadian solar. roof. 3kw solis G98 mcs
12kw midea ASHP
200l hot water
3152W RE, Whitelaw Brae
Octopus agile/outgoing fixed 15p

Planned;
Hybrid system
43kwh eve batteries, 3x16 280A
6-8+kw solar, DC connected.
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