Please Check My Mixed Solar Panel Math

[featherlite]

I have (2) 100 W Panels connected in parallel (two Rich panels).

I want to add (1) 200 W panel (an Acopower panel) to be connected in series with the above two panels.

Below is my math.

I used Vmp and Imp values.

I would appreciate it if you would please review this proposed set up and let me know If my thinking is correct.

Thank you.

 

[Suijkerbuijk]

One moment

Yes it can work.
But if your one of the 2 x100 panel go in the shade the systeem wil be unstable.
I will go for 2x100 panels extra panels and not go for 1 x200 watt

Or go for all in parallel.
Than you never have a problem if one go in the Shadow.
If you use a 12 volt battery i go for that setup

 

[Rocketman]

Yep - you nailed it!

In addition to doing the math correct…

You managed to find the perfect panels to put together- and that is the hardest part of all!!!

Good Luck

 

[Rocketman]

Wrong .

Your 200watt panel gone do 100 watt.
In Series the Lower panel will be the leader .

So you will do 300 watts max.

So parallel is the only option to have the max use

The two 100w panels in parallel make a 200w panel that he has indicated in Gray.
Then he can take that “Gray” panel and put it in series with the new 200w panel.

I did the same thing a while ago on my MotorHome- I had two 210w panels in series and needed a little more power - I found two 100w panels that when combined in parallel were almost the same Vmp and Imp as the 210w ones - I then put the two 100w paralleled panels in series with the other two 210w panels. If I remember correctly, I had a max potential of 602w from the 620w array - after the electric penalty of mismatch panels- I thought I had done very good (I had), but compared with the O.P. @featherlite that only has a 1 watt penalty- we know who found the best panels to put together!!!

 

[featherlite]

Thanks for all the replies.

I have a cargo trailer already loaded with (10) 100W panels on the roof, split into different arrays, feeding different Victron 100/50 MPPT's. Some are wired in parallel and some are wired in series. I only have remaining space for one more panel on the roof.

However, the remaining space will not physically accommodate two more 100 W panels. Consequently, I am looking for a larger panel to fill up the space as much as possible.

I have not found any 250 W panels that i can use due to voltage and amp differences (i.e., the ones I looked at wasted all the extra 50 watts).

The 200 W Aco panel in my schematic matches up pretty good.

Now that I have some degree of confidence in what I am doing, I am going to start figuring out how to further integrate the panels shown in the above schematic into the other existing arrays on the roof, which will require more panel mixing math.

When I update my schematic, I will ask you guys to review it like you did this one.

PS: My battery is a DIY, 12v, 560 Ah Lifepo4 battery (two 280Ah batteries connected in parallel).

Again, thanks!!!

 

[Suijkerbuijk]

The two 100w panels in parallel make a 200w panel that he has indicated in Gray.
Then he can take that “Gray” panel and put it in series with the new 200w panel.

I did the same thing a while ago on my MotorHome- I had two 210w panels in series and needed a little more power - I found two 100w panels that when combined in parallel were almost the same Vmp and Imp as the 210w ones - I then put the two 100w paralleled panels in series with the other two 210w panels. If I remember correctly, I had a max potential of 602w from the 620w array - after the electric penalty of mismatch panels- I thought I had done very good (I had), but compared with the O.P. @featherlite that only has a 1 watt penalty- we know who found the best panels to put together!!!

His drawing is not perfecte on my phone
So i al ready change it.

Only problem with it is that if one of the 2 solar panel in parallel (100watt) do not performed on top to Shadow.
The hole systeem wil performance les
Means that the 200watt panel will go down if that panel is indeed in the full sun.
And one of the 2 100watts in the Shadow.
If no shadow come on the 2 x100 panels than its go fine

 

[featherlite]

The hole systeem wil performance les

Thanks for pointing that out.

I appreciate the fact that with panels wired in series shading is relatively a bigger problem compared to parallel wiring. I already have one array wired in series and another array wired in parallel. So far, it has not been a problem because I have managed to avoid shade conditions. The experiment continues.

I am dealing with 30 feet wire runs, using existing 10 AWG wire, and want to minimize voltage drop, so wiring in series helps.

If I wired the three panels in parallel, assuming a combined 20 A draw, I would not be comfortable without running 6AWG wire, which I do not want to do.