Hi all, after some advice from you knowledgeable lot if I may. I have solar on my main roof (16 x JA 385w), that is fed into my hybrid inverter. I also have a Victron MP2 8000VA with four PylonTech US5000’s. I’m thinking of adding some solar panels to the DC side of my MP2/PylonTech’s. I have spare ways in my 2nd Lynx Distributor.
Question 1: I have space for 4 panels on the roof marked in red. Any recommendations on best panels to use? To maximise the space I’m thinking 4 panels in landscape orientation. However, I’m a bit limited on the width of the roof (its 3450mm). I was looking at the REC Alpha Pure-RX range as these are 1728mm (so two would just fit), but their a bit pricey! I guess these are fairly premium panels and maybe a bit overkill for my situation?
Question 2: Once I’ve decided on which panels, how best to determine which Victron 48V MPPT to use? I’ve been playing with the MPPT sizing calculator but its not super clear to me. I’m not sure if I need 4 panels in series on 1 string, or 2 panels in series on 2 strings?
I cant really help with choosing the panel type. Id use whatever fits the space and the budget, but i guess thats exactly the core issue of your first question.
As for the MPPT, yes, as soon as youve defined the panel type you then use that to define the MPPT.
In general, using a single series string is beneficial since the PV voltage will surpass the necessary threshold sooner in the morning to allow for early charging, and vice versa in the evening.
However, the necessary 250/60 is much too big in terms of output current (a 250/30 would suffice, but doesnt exist), so using a 2S2P config on a 150/35 could be beneficial due to the price difference between the two. The bit of extra energy due to the 4S config on a 250/60 would propably take decades to break even compared to the almost half priced 150/35
This will depend on panel (that you have chosen) VOC at min temps and the charge controller voltage chosen (150 or 250).
But the basic maths is as follows.
And the X50/YY where the YY is total wattage ÷ 48V.
eg. (375w x 4)÷48 = 31.25A . Nearest is X50/35. The 150/35, which will probably mean the panels are 2S2P connected unless the isc is above the max short circuit of the mppt which is 35A.
Hi all, just following up my initial question. I have two options on panel selection, and I’d really appreciate some help deciding which one is better.
Option 1: 3 x Aiko 650w (1950w total) in portrait, using a Victron 250/60
Or
Option 2: 4 x Perlight 415w (1660w total), 2S2P configuration, using a Victron 150/30 or 150/45
The Aiko’s are silver frame, and I guess mostly designed for commercial uses, not to say they can’t be used in a residential use case like mine? Being in portrait I’m thinking 2 or 3 horizontal rails to mount them.
The Perlight’s are All Black, and are designed for residential, but are a lower wattage. Also, would need 4 vertical rails to mount them.
Any help/reasoning for selecting one or the other would be great as I’m stuck on the fence.
11.12x2 x1.25 =28A - what ever is closest to that figure that you can get supplied. So probably a 32A DC breaker.
Most ideally you also want to fuse each string. Easy to do if you can get the fused MC4 connector sets.
Those inline ones are the most convenient
Each string should be fused before they are combined.
Easy enough to do since you will probably/possibly need to make a jumper from one end of the array to the Y connector. Just plan it so the correct one is fused. (Unless the solar panels have nice leads on them.
Ideally each string is individually fused. Then after the combiner (y connector in this case) the breaker/ disconnect like the one you linked will be good.
