20x400w Or 22x400w, Solis 6kW hybrid inverter, South facing roof - System limitations

Moreilly

Solar system on the way for the house, should be end of Feb/March install, Looking at 20x400w panels on a directly south facing roof

Question is - The inverter is a Solis RHI-6K-48ES-5G 6kW Hybrid and i think it is capable of taking an extra 2 panels (one per string), Is it worth putting up the extra two panels during install, i realise even with the 20 panels i will get clipping during the good weather, but when the weather is not so good i assume the more panels the better.

Is it taxing on the inverter to have that amount of panels when weather is optimal?, what are the limiting factors? is there a max voltage per string and how would i work that out?

Loads of questions !! 🙂

Bakka

https://www.boards.ie/discussion/2058274125/20x400w-or-22x400w-solis-6kw-hybrid-inverter-south-facing-roof-system-limitations

I have a 9.1kw ground mount system and on an ordinary 6kw Solis inverter. Sure there is clipping on a good summers day which is no problem. But most days there is no clipping and I am glad of the extra panels all year round. The 6kw can easily take 9kw of panels but I wouldn't oversize any larger than that, which is oversizing by 50%. Go for the extra 2 panels. Big is beautiful and productive.

Gerry

You should be able to find the manual for the inverter online and it will include the max voltage per string. It's worth double checking

unkel

Yes, as @Gerry said, look up the max input voltage per MPPT string from your inverter and divide by the VoC of your panel and then round down to the nearest whole number. This is the max number of panels per string

And the more panels you fit, the better. If you don't max out, you will kick yourself later. Don't ask me how I know this 😂

Moreilly

Solis RHI-6K-48ES-5G

Leapton 400w

https://www.boards.ie/discussion/comment/119957079#Comment_119957079

Thanks for the replys - The max string voltage on the inverter 520v and the VoC of the panel 36.94 = 14 panels ,Are these the correct figures?

unkel

Yep. Well done. You got your answer.

That's a pretty low VoC for a 400W panel, but all panels are different. Best of luck with the install of your 22 * 400Wp panels 😎

Moreilly

https://www.boards.ie/discussion/comment/119957767#Comment_119957767

Thanks for that! 🙂 The recommended max PV power on the inverter specs above is 8kW + does lt matter that the panels will add up to 8.8kW?

bullit_dodger

https://www.boards.ie/discussion/comment/119958006#Comment_119958006

It can do. Generally it's not a great idea to surpass the specs (they list them for a reason!) That said, are all your panels in the same orientation? Or are they split E/W for example. If they are split, even in the height of summer it's unlikely you'll be outputting your max Kwp due to the sun not being directly overhead all the panels at the same time - although if you have a low slope on the roof you'd want to watch that.

Moreilly

https://www.boards.ie/discussion/comment/119959305#Comment_119959305

All panels on the same roof facing directly south !, although I see the spec sheet it says 'recommended' max PV power 😁😁⚡💥🙁

creedp

https://www.boards.ie/discussion/comment/119960388#Comment_119960388

Looking at same issue myself and wondering what you finalised on?

I got a quote for a SOFAR 6KTLM-G2 inverter with Tiger Jinko 400 -420w panels. According to inverter spec the recommended max PV input power is only 6,600w but the MPPT Voltage range is 90 - 580v. When coupled with the Voc of the panels at 38.15v this would give a theoretical 30 max number of panels. However the combined max PV input of 30 panels would be 12,000 watts. There seems to be a massive variation between the 2 specs.

I am considering installing 20 panels (8 - 8.8 kwp) so am wondering which takes priority, the max PV input power in Kw or the max MPPT voltage. Or am I better off seeking the installation of a different inverter with a higher max PV input power limit?

samdeluxjones

https://www.boards.ie/discussion/comment/119943723#Comment_119943723

Is your inverter same as this one?

Did you choose to put 9kW of panels on your self or your installer?

axe2grind

I got 22 x 400w panels married to 6kW hybrid inverter. South facing.

I was getting clipping in early Feb! but it's all the time that it isn't sunny that sees the benefit of the extra panels. If the DC battery has capacity it can take the generation in excess of the inverter 6kW capacity

Bakka

https://www.boards.ie/discussion/comment/120545068#Comment_120545068

I have this inverter. Hope this helps

Ha Long Bay

https://www.boards.ie/discussion/comment/120563609#Comment_120563609

Looks like the 6K non hybrid inverter supports 9 kw.

The hybrid 6k supports 8 kw

Bakka

https://www.boards.ie/discussion/comment/120563692#Comment_120563692

I have a 9.1kw ground mount system and there is no issues with it at all. I made 880 kw last month. I am very happy with my system and output

Ha Long Bay

https://www.boards.ie/discussion/comment/120564200#Comment_120564200

Nice system I was just posting to show the difference between the hybrid and non hybrid 6K inverters where the non hybrid seems to allow a larger array.

Also curious do you have an EV to soak up some of that generation?

Bakka

https://www.boards.ie/discussion/comment/120564229#Comment_120564229

No EV or battery. All excess goes to the grid. With FIT being higher than expected I'm not too bothered. I use up as much as I can during the day, and leave the rest as FIT.

samdeluxjones

https://www.boards.ie/discussion/comment/120564200#Comment_120564200

I have 6k ground mount too and adding another 3 now up on a shed on some sort of a crude tracker.