question

danielgee avatar image
danielgee asked

Smart Solar MPPT 100/30 max panels

I just recently bought a Victron MPPT 100/30. Currently I have a (1)Go Power 200W panel with these specs:

Solar cell type Monocrystalline

Output power

200 W

Rated current

 9.62 A

Rated DC voltage

20.8 V
Open-circuit voltage 24.3 V


and one of these(1( Go Power Panels:

Solar cell type Monocrystalline

Output power

100 W

Rated current

 5.43 A

Rated DC voltage

18.4 V
Open-circuit voltage 22.6 V


I would like to add one or two more of the 200W version above. Will I be able to use my current controller that I just purchased this past summer? I suppose I should have asked this first before buying the 100/30. It would be a bummer having to buy another controller. If I have to, I'll get rid of the 100W one and just run two more of the 200W version if it means I can keep my current MPPT controller .


MPPT Controllers
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4 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

It's not recommended to connect different panels together to one MPPT.

You should have one MPPT for each panel type.

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danielgee avatar image
danielgee answered ·

According to Go Power's website, the two panels I have are compatible with each other. Are they not when using this MPPT controller? I had a Go Power PWM before replacing it with the Victron 100/30.

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snoobler avatar image
snoobler answered ·

Panels can be safely mixed and matched following two simple rules:

  1. Panels in parallel need to have very similar Vmp - typically within about 10%.
  2. Panels in series will operate at the current of the LOWEST rated panel.


You have two "12V" panels with Vmp 18.4 and 20.8. That's about 11.5% difference. They are not a great match.


If you put them in parallel the total array will take a performance penalty as much as the difference, 11.5%


If you put them in series, the 5.43A panel will force the 9.62A panel to work at 5.43A thus killing nearly 50% of its output.


If you place 3 200W in parallel with the 100W, the total array will suffer as much as 11.5% performance penalty. Each panel will require its own fuse or breaker (3 or more in parallel require this).


Partial shading performance may be notably impacted.

4 comments
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danielgee avatar image danielgee commented ·
What about getting rid of the 100W panel and just getting two more of the 200W. Will my current MPPT 30/100 be ok for this?
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snoobler avatar image snoobler danielgee commented ·

Yes. Either in 3P or 3S configuration. If 12V battery (max output of about 435W), you will be over-paneled, but are within limits.


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danielgee avatar image danielgee snoobler commented ·
Thank You for your help. I think I will buy two more of the 200W for a total of 3 and remove the 100W. Keeping my Victron 100/30.
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snoobler avatar image snoobler danielgee commented ·

Good plan

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bladerunnervf avatar image
bladerunnervf answered ·

See

https://www.victronenergy.com/mppt-calculator

Enter your panel specs and away you go

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