Charge controller for each solar panel?

[epiic]

How important is it to have a mppt solar charge controller for each solar panel.

I understand that it helps to make the system more efficient so that when one solar panel is shaded, it won't effect the others but it really complicates the installation.

I have seen plenty of installs and I almost never see people doing it this way.

Thoughts?

[Cotemar]

epic,

Depending on your solar panels and there output, you should only need 1 MPPT controller.

Always try to wire your panels in Parallel first.

Only wire in series if your HAVE to.

When cruisers go up into the 1000+ watt solar panel range then you may need 2 MPPT controllers as that is driven by how much power the MPPT controllers will support.

[Zanshin]

I have a different approach to the previous poster. I've got 6 solar panels and each has a dedicated MPPT charge controller. This way if one panel is shaded the power output of the others isn't affected. Here's my controller board that I put together:

[epiic]

I purchased 5 Solara S565M44 140w Ultra (SunPower cells). 700w total.

I was told by the dealer to use 5 Victron MPPT 75/15 solar controllers (one for each panel).

The issue I am having is I also ordered the Victron Color GX display panel and it can only accept a single mppt charge controller. In order to connect all 5 to the display, I need to install a network hub, connect all 5 to the hub and then go from the hub into the display panel.

The install is significantly more complex and messy. I just want to make sure that if I do go this route, that its worth the trouble.

[socaldmax]

I think it's worth it. My most popular install these days is 2 320 watt panels with a 20A MPPT controller on each one.

[Paul L]

I have 4 panels total. They are wired in parallel pairs. I have one controller for the two on the arch and one for the two on the bimini.

[epiic]

Originally Posted by Zanshin

I have a different approach to the previous poster. I've got 6 solar panels and each has a dedicated MPPT charge controller. This way if one panel is shaded the power output of the others isn't affected. Here's my controller board that I put together:

What are these? (circled in blue)

[socaldmax]

Those look like shunts used to measure output current, since those controllers don't have a display.

[arsenelupiga]

Originally Posted by socaldmax

I think it's worth it. My most popular install these days is 2 320 watt panels with a 20A MPPT controller on each one.

Why 20A, why not 30A MPPT ? Some power gets wasted as 320W produces up to 27 A.

[socaldmax]

Originally Posted by arsenelupiga

Why 20A, why not 30A MPPT ? Some power gets wasted as 320W produces up to 27 A.

27A? Only if you have 100% solar output on a tracking mount and your batteries are down to 11.85v. That's theoretical, not realistic.

My experience has been flat mounted 320w panels will make 18-19A, possibly 20A. The controllers will go up to 22A if necessary, but I doubt it will have to very often.

Between sun angle, clouds and the batteries being fully charged most of the time, these controllers will see 20A less than 10% of the time. These guys are installing solar based on their peak usage, and very rarely do they hit those peaks.

[arsenelupiga]

Originally Posted by socaldmax

27A? Only if you have 100% solar output on a tracking mount and your batteries are down to 11.85v. That's theoretical, not realistic.

My experience has been flat mounted 320w panels will make 18-19A, possibly 20A. The controllers will go up to 22A if necessary, but I doubt it will have to very often.

Between sun angle, clouds and the batteries being fully charged most of the time, these controllers will see 20A less than 10% of the time. These guys are installing solar based on their peak usage, and very rarely do they hit those peaks.

thanks for explanation. I planned to install 2 X 360W sunpower, replacing current 2x 180W, however started thinking that what really matters is low light panel performance. And not necessary sunpower 360 are the best in this area. At least have not seen any evidence yet. Only real measurements with low light have seen for Panasonic panels.

Any idea which panels do best in sub optimal days ?

[a64pilot]

If you wire in parallel and only have one MPPT, then shading will effect you no more or less than it will if you have an MPPT for each panel, I don't think.
Wiring in series is where it hurts.


Sent from my iPad Pro using Cruisers Sailing Forum

[epiic]

Originally Posted by arsenelupiga

thanks for explanation. I planned to install 2 X 360W sunpower, replacing current 2x 180W, however started thinking that what really matters is low light panel performance. And not necessary sunpower 360 are the best in this area. At least have not seen any evidence yet. Only real measurements with low light have seen for Panasonic panels.

Any idea which panels do best in sub optimal days ?

Holly thread hi-jack!

The purpose of this thread is to determine if its worth having a single mppt controller for every panel vs having a single large mppt controller for all panels.

The issue I am having is that I cannot monitor all 5 controllers, I can only monitor one. So I give up monitoring for the extra efficiency.

[arsenelupiga]

Originally Posted by epiic

Holly thread hi-jack!

The purpose of this thread is to determine if its worth having a single mppt controller for every panel vs having a single large mppt controller for all panels.

The issue I am having is that I cannot monitor all 5 controllers, I can only monitor one. So I give up monitoring for the extra efficiency.

i am in camp - 1 controller per panel.

Because boat came setup like that and I trust previous owner competence.

Also redundancy, as wiring on 1 controller failed, second one worked fine and kept batteries reasonably charged until I managed to repair with my mediocre knowledge of solar installation. Would be worse for batteries with 1 controller only.

With panels will upgrade 2 controllers as well and add 2 x dongles for monitoring via mobile phone. And will become expert !

[socaldmax]

Originally Posted by arsenelupiga

thanks for explanation. I planned to install 2 X 360W sunpower, replacing current 2x 180W, however started thinking that what really matters is low light panel performance. And not necessary sunpower 360 are the best in this area. At least have not seen any evidence yet. Only real measurements with low light have seen for Panasonic panels.

Any idea which panels do best in sub optimal days ?

From everything I've read, the Sunpower panels are substantially better than any other brand, especially if you get any shading. Other panels could lose 40-80%, while a Sunpower under the same conditions would only lose 11%. Their low light performance is probably also exceptional for the same reason they are the most efficient - all of the connections are on the back, there are no silver strands on the front.