mixing different size PV panels

mun1 · 09-03-2021 12:00PM #1

looking at upgrading my array (DIy build). getting a bit jealous with everyone posting about their 6-10kWh array

have 8 x 315W Longi panels which are south facing on one string and 4 x 315W on another string facing west .

I'm going to add another 4-6 panels onto the south string ( onto wall on brackets).

one company in Dublin will sell me 360W longi panels for same price as I paid for 315 panels last year.

as I understand it if I add these 360W panels to the 315W panels then I would be limited by the current (Ip) in the 315 panels (all panels connected in series).
both panels have very similar voltage .

any thoughts ?

my other options to change out the 4 x 315 panels and add them to this string and put the new 4 x 360W panels onto the west facing string.

either option will up my array from 3.7 kw to 5.2kw. for aprox €700.

unkel · 09-03-2021 03:06PM

Yes you're right on both counts. I'm in the same situation and I have just accepted the fact that I am losing about 65W per panel max. Either that or pay a roofer to replace the panels on my high roof (which will never pay for itself)

quentingargan · 10-03-2021 01:29AM

Maybe look for some 320w panels of a different brand, but with similar current. The 320w are usually smaller so you can fit more, and cheaper too, so more watts per €

mun1 · 10-03-2021 08:57AM

The voltage current curves would need to be similar I’d say, thats why i was looking at the 360W longi to add to the 315 W longi .
Trying to source some 315W longi today , as it will the easiest effort.

mun1 · 10-03-2021 02:42PM

320 amerisolar panels are similar in size and VP and IP ranges. Might have a closer look at these

mun1 · 17-03-2021 05:09PM

Added in the 4 x 320W amerisolar panels today .

They are at 45 deg angle (brackets on wall) and other 8 on string are at approx 40 deg on shed roof. (All facing south)

Everything seems to be working fine, getting the correct boost in voltage.

Array now at 5 kw and even though today is hazy and cloudy on 11kwh , which seems good .

Gumbo · 18-03-2021 03:28PM

I have 10x300w panels on front and 5x340w on rear.

mun1 · 18-03-2021 09:47PM

I needed to put the extra panels on the same south facing string where i have 8 existing 315 panels .
The other string is taken up with west facing panels.

buzz11 · 21-03-2021 08:32AM

mun1 wrote: »

Added in the 4 x 320W amerisolar panels today .

They are at 45 deg angle (brackets on wall) and other 8 on string are at approx 40 deg on shed roof. (All facing south)

Where did you source wall brackets?

Could you post a photo of the wall mounted panels? I'm interested in doing the same but unsure how it will look.

Thanks!

mun1 · 21-03-2021 12:11PM

Got brackets form amazon.co.uk and used M8 rawl bolts for top fixings

unkel · 21-03-2021 11:18PM

Linky to the brackets?

mun1 · 22-03-2021 09:27AM

https://www.amazon.co.uk/gp/product/B07S19PJTF/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

slayer91 · 24-03-2021 10:10PM

Hi,

I am planning to do something similar, could you please post details of how you attached the sloping PV panels to the brackets

Regards
Liam

mun1 · 24-03-2021 10:21PM

Mounting instructions and fixings to attach panel to bracket come with the brackets

mixing different size PV panels

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