So just before I buy the last pieces of the puzzle I was hoping for some feedback. 
 

my system:

8kw sunsynk

3 x 5.12kw sunsynk lithium (sslb1) 

panels?? 
 

my original idea was 18 x 545watt, then it changed to 16 x 545watt Because of safety and voc and so on. Now the 545watt is out of stock so I’m going for the next best thing which is 16x 470 watt

i think this will suit me best in terms of adding panels in the future because the amps from each panel are 10.8amps.. so if I add panels later I could do a couple in parallel and have about 22amps going to the inverter which the inverter will cap at 18amps? 
 

so in theory in the long run you could add 18 panels , 8per string and 2 string parallel on one mppt so it would be 22amps of about 400voc. 

then 18 panels on the 2nd mppt with 8 per string and both strings parallel giving me the same, 22amps and 400voc
 
Would this work? Does it make sense? 

Tiger 470W Mono-Facial 

• Electrical Data | STC*
• Nominal Max. Power (Pmax): 470W
• Opt. Operating Voltage (Vmp): 43.28V
• Opt. Operating Current (Imp): 10.86A
• Open Circuit Voltage (Voc): 52.14V
• Short Circuit Current (Isc): 11.68A
• Module Efficiency up to: 20.93%

20 minutes ago, Derek Ramos said:

so in theory in the long run you could add 18 panels , 8per string and 2 string parallel on one mppt so it would be 22amps of about 400voc. 

then 18 panels on the 2nd mppt with 8 per string and both strings parallel giving me the same, 22amps and 400voc
 

is the idea to have 2 and 2 spare panels? one spare panel per string? 🙂

17 minutes ago, Kalahari Meerkat said:

is the idea to have 2 and 2 spare panels? one spare panel per string? 🙂

The idea is to have 36 panels (not now but maybe future)

mppt1- 2 strings of 8 panels each connected in parallel. (16 total panels) a little over 400v and 22amps

mppt2- 2 strings of 8 panels each connected in parallel. ( 16 total panels) a little over 400v and 22amps. 
 

for now I just want to get 16 panels, 8 panels in series on one string on one mppt and the same for the 2nd mppt. 
 

the question I’m asking is that in future could 36 panels work the way I’ve said above and would it be beneficial to get 470watt panels instead of 545watt for future expansion. 

49 minutes ago, Derek Ramos said:

The idea is to have 36 panels (not now but maybe future)

yes, but you wrote "18 panels , 8per string and 2 string parallel" which is 8+8 + 2 spare panels 🙂

not sure of the specs, but since the 470W panels are available and the 545W aren't if you put 8 + 8 that would be 7k5Wp then you can combine this bunch on the one MPPT in the future, when you add more panels which aren't likely to be the same specs in the future and the new panels can the be on the 2nd MPPT, I'd think...

 

Edited July 11, 20223 yr by Kalahari Meerkat
spelling etc.

58 minutes ago, Derek Ramos said:

The idea is to have 36 panels (not now but maybe future)

mppt1- 2 strings of 8 panels each connected in parallel. (16 total panels) a little over 400v and 22amps

mppt2- 2 strings of 8 panels each connected in parallel. ( 16 total panels) a little over 400v and 22amps. 
 

for now I just want to get 16 panels, 8 panels in series on one string on one mppt and the same for the 2nd mppt. 
 

the question I’m asking is that in future could 36 panels work the way I’ve said above and would it be beneficial to get 470watt panels instead of 545watt for future expansion. 

The 470W panels at 9x52.14V goes over 450V and that at 25deg

Posted an hour ago.

Edited July 11, 20223 yr by Scorp007

3 hours ago, Derek Ramos said:

Now the 545watt is out of stock so I’m going for the next best thing which is 16x 470 watt

Segen have plenty stock, find out if your supplier has an account with them

JA Solar

545W Mono PERC Half-Cell MBB MC4

2,577 In Stock

Canadian Solar

545W Super High Power Mono PERC HiKU with MC4-EVO

1,420 In Stock

 

 

 

6 hours ago, Kalahari Meerkat said:

yes, but you wrote "18 panels , 8per string and 2 string parallel" which is 8+8 + 2 spare panels 🙂

not sure of the specs, but since the 470W panels are available and the 545W aren't if you put 8 + 8 that would be 7k5Wp then you can combine this bunch on the one MPPT in the future, when you add more panels which aren't likely to be the same specs in the future and the new panels can the be on the 2nd MPPT, I'd think...

 

@Kalahari MeerkatSorry man, my brain and hands were not collaborating with each other… I wrote down 18 but I ment 16. 
 

but thank you so much for the idea, when eventually I want to expand I can use the 16 I’m about to buy on one mppt because that will work if I have 2 strings of 8 each,  connected in parallel. Then just get whatever is available for the 2nd mppt, or try and match the 1st mppts panels. 
 

thank you for the reply. Much appreciated. 

6 hours ago, Scorp007 said:

The 470W panels at 9x52.14V goes over 450V and that at 25deg

Posted an hour ago.

Thanks @Scorp007i ment to say 8 panels and not 9..

thank you for the reply. Much appreciated 

4 hours ago, WannabeSolarSparky said:

Segen have plenty stock, find out if your supplier has an account with them

JA Solar

545W Mono PERC Half-Cell MBB MC4

2,577 In Stock

Canadian Solar

545W Super High Power Mono PERC HiKU with MC4-EVO

1,420 In Stock

 

 

 

Thanks for this, unfortunately I was planning on going for the tiger panels from solar and inverter warehouse, they 15min from my house and easy for me to collect. They cost R3150 for 470watt which is pretty similar in price to most of the panels in that range. 
 

what I’m thinking with the 545watt is that if I do 16 on one mppt ( 8x8 in parallel) in the future the amps on 16 panels would be about 26 and the watts if I done it on both mppts would be like 17400watts. I know the inverter throttles the amps and watts but would that not be damaging to the inverter if it’s constantly trying to throttle down such a big difference ? Also the inverter can only take 10400 DC watts. Would it be and overkill to have a 17400watt or 15000 watt array if you inverter can only take 10400 watts
 

not exactly sure which way to go here.