I have 2 growatt inverter connected in parallel, and 2 5kw Li Batteries.

I need to update my solar panels and are reading conflicting messages regarding the setup  ( series vs parallel or a combination) What will be the best setup to use?

And what number or panels ( total voltage and wattage) 

Your inverter is a 450VDC inverter which means you have to combine your panels in series to add the voltage of each panel to get to 400 volts. For example if your panels are 40 volts 10 of them in series gives you 400 volts. Some of the newer 500 watt panels are 50 volts which means 8 or 9 in series would be below the limit of 450 volts.

Basic rule is high voltage(450vdc) inverter need panels in series strings, low voltage( 145vdc) require parallel strings of 2 panels in series.

There are exceptions but I'll leave it at the basics.

Thank you, this helps me allot. I can reconfigure one set, its currently 3 parallel strings with 3 in Series (9panels), changing them to all in series give me approx. 360v. the second set has 3 in series and the 2 sets in parallel (6 panels) adding 6 more panels ( if I can find the same type?) I can create another set with 12 panels that will give me approx. 360v also.

What is your view on this?

360 volts is perfect, the nominal voltage is 340 volts. 

 

I'm guessing that if the voltage without any load is 360 it will be around 300 under load which is perfect.

One more detail is how much wattage your panels produce which should not be a problem since each inverter can take 6000 watts of pv so potentially you could have 12kw of panels.

Just to give feedback, this morning I changed one array (6 panels 3 par, 2 serie) to  6 in serie, look at the huge difference it made in production

picture 1 from today, picture 2 and 3 from the 31st

Tomorrow I will do the other 9 and share the result

thanks again for your feedback

Hello everyone,

Sane advice on this thread so far.

@Deon_J - These inverters caps the amps it pulls from the panels to 18A, so if you have multiple strings that you combine, everything over 18A would be a waste and possibly result in clipping.

Bottom line - Look at your panels specs (Open Circuit Voltage - VOC and Short Circuit Current - ISC specifically) and try to determine from there which combination of series panels vs parallel strings you need to combine to get the max out of your panels and into your charge controller on the inverter.

Also, you could post the specs of your panels here and we can constructively debate through it to see what the best fit would be over the 2 inverters.

 

Hello every one

Totally agree with @Supergeek

However in my specific scenario I’m fixing a really bad installation, it was working ok with 2 king inverters but then they died. The insurance replace them with the 2 growatts. I didn’t  notice that they need higher voltages froM the panels. After a few days I realize that I was using utility power like crazy, that’s when I started to investigate and saw that they need a higher supply.

The one solar bank I could change at the fuses, ( old installation but done well) the second bank I can’t do the same, the idiot that installed them cut the connecting plugs and linked them together on the roof bringing just one positive and negative cable down using  normal electrical wire!!!

At some point I will need to lift the panels and check that all is ok and fix the wiring and get the panels info 

I will brave the heat this afternoon to change the panels from 3 series 3 parallel to 9 in series and give feedback tomorrow

wish me luck its 35 deg in pta today

Hi Everyone @Buyeye, @Supergeek

Time for feedback, I made all the changes and the system is running like a charm. After a lot of pain I finally off grid.

since I connected all the panels in series my daily production went from about nothing to an average of 9.9 kwh

see the attached graph. You will see that before the 3rd nothing shows , that was the production I had before the change

( note to myself ! Even solar panels can give you quite a big shock, I covered them when I was working and touched a open wire, I nearly fell of the roof!,)

thanks for the support

Hi I have 10 x Jinko tiger pro panels of 545w should I use 1 or 2 growatt 5kw inverters?

Hi Morne using 2 inverters depends on whether or not you need 10kw for peak loads? In that case yes 5 panels per inverter will work. If you only need 1 inverter upto 9 panels in series should be safe with 10 being over 450 volts under certain conditions. 

Hi,

Looking to get solar panels installed. I have spf5000es paired with a hubble 5.1kw lithium battery. 

Would 9 x 450w or 9 x 540w Canadian solar/JA solar panels be best? 

TIA 

Guys I have 30 panels 460W https://shop.solartec.eu/user/documents/upload/produktove-katalogy-PDF/Solarn%C3%AD%20panely/LP182-M-60-MH440-460W.pdf. I wanted to use 10 in series for each of 3 invertors. But I calculated i hit 450V at -3C. We get to -5 max in winter for just couple of days max.. Is this still ok?

The link is not working. 

11 hours ago, Nemon said:

Guys I have 30 panels 460W https://shop.solartec.eu/user/documents/upload/produktove-katalogy-PDF/Solarní panely/LP182-M-60-MH440-460W.pdf. I wanted to use 10 in series for each of 3 invertors. But I calculated i hit 450V at -3C. We get to -5 max in winter for just couple of days max.. Is this still ok?

You provided your own answer. 10 is a no go.