question

Josep morancho avatar image
Josep morancho asked

PV panels to maximize PV production in MPPT RS in winter

I am trying to find the best PV panels for MPPT RS to maximize production in winter.

The most usual 144 cells panels with power between 500w and 600w have a Voc around to 50V and IsC around 13A. With these panels the new mppt calculator allows strings of 7 panels in serie and gives me around 40Kwh of PV production in January.

Said that I have found another panels in the same range of power but less usual where the VoC is a little bit higher than 40V and the Isc is around 18A. With these panels the mppt calculator allows strings of 9 panels in serie and the production in january increases to 50kwh.

is there any secondary effect/issue by using panels where the Voc is lower and Isc is higher?

Thanksimg-9353.png



Solar Panelmppt rs
img-9353.png (731.6 KiB)
2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

nesswill avatar image nesswill commented ·

Hi do you have a link to the datasheet please?

is there any secondary effect/issue by using panels where the Voc is lower and Isc is higher?

The only thing that springs to mind is distance to/from the MPPT and cable type/spec (connections/connectors) but i would need to see the full datasheet before i comment any further.

There are pros & conns with volts v amps, really what suits you and your system. I try to keep it short, simple and safe.

0 Likes 0 ·
Josep morancho avatar image Josep morancho nesswill commented ·

Here the link to the TTW datasheet panels

https://ttw-corp.com/wp-content/uploads/2024/01/TTW_Brochure-Solar-cell.pdf

Below also some feom Trina Solar with similar characteristics.

https://cdn.enfsolar.com/z/pp/2024/2/3hs5laff8cuqv3/186757691665bf2992425c0.pdf

They are not 144 cell panels, but 120/132 cell panels. I want to understand that this is the reason behind the low Voc value.

What makes me unconfortable that none of the more known brands, chinese and not chinese, does not produce this type of panels.

Here the link to mppt calculation with trina panels. Distance from panels to mppt will not be more than 50m and cable size will be 10mm2

Mppt calculator with Trina panels

186757691665bf2992425c0.pdf

0 Likes 0 ·
186757691665bf2992425c0.pdf (725.4 KiB)
1 Answer
nesswill avatar image
nesswill answered ·

To be honest i would stick with known brands. I am off-grid and maximising solar production is just one part you will need to build an efficient system from your panels (how they are mounted and direction they point with the correct angle) to your home and what and how you use the power.

Good quality/spec cabling matching cable lengths where required and how its connected will all add up as will the quality of the electronics (airflow around equipment) and how many devices you have connected will influence overall efficiency.

Monocrystalline PERC panels are better than Polycrystalline but there is new stuff coming out all the time. The best solar panels now use heterojunction (HJT) or Tunnel Oxide Passivated Contact (TOPCon) technology instead.

I have x50 Monocrystalline PERC panels and will buy more soon. And also consider when cloudy I find my PERC still produce good power so low-light performance is important to me.

"Distance from panels to mppt will not be more than 50m and cable size will be 10mm2"

6mm2 would probably be ok at a higher voltage over 50m, i don't see any loss on my 6mm2 @35m with a voltage 350 to 400v, but if the current increases you might need the 10mm2.

I always sceptical of some claims and worry about longevity and support of the product. Sorry i can directly answer your question but hope this helps.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Related Resources

MPPT RS Product Page

MPPT RS Datasheet  

MPPT RS Manual  

MPPT Error codes

MPPT RS Manual Error codes

MPPT RS Training Video

Additional resources still need to be added for this topic