I'm I overpaneling Growatt?

[oshky]

Hello,

I own the Growatt SPF 3000TL (24 volts) with a 1.2Kw solar panels. I have noticed that sometimes all 1.2 Kw are coming into the system (consistently for about 15 minutes). Is that normal? My expectation according to some articles is a 75-85% of PV efficient. That would be like 900-1,020Kw.

In case a need to upgrade to a 2Kw PV (max input for my Growatt), Will this cause a 'overpaneling'? I don't want to fry the Growatt? Voc, Vmp and Imp will be between limits.

I appreciate any comment.

 

[farmhand]

I'm overpaneling an EcoMax 300%, week 4 no problems. Good luck!

 

[BobT]

I have the same Growatt inverter and have 1.6 kW of PV connected (4S4P). I am a believer in following the manufacturer's specification so I used the excellent Victron calculator found at https://www.victronenergy.com/upload/software/VE-MPPT-Calc-4_0.xlsm to verify that I would not exceed the PV input at all temperatures I reasonably might encounter at my location. You will have to input the parameters for your panels on the "Modules" tab of the spreadsheet but that is an easy operation. Better safe than sorry.

 

[oshky]

I have the same Growatt inverter and have 1.6 kW of PV connected (4S4P). I am a believer in following the manufacturer's specification so I used the excellent Victron calculator found at https://www.victronenergy.com/upload/software/VE-MPPT-Calc-4_0.xlsm to verify that I would not exceed the PV input at all temperatures I reasonably might encounter at my location. You will have to input the parameters for your panels on the "Modules" tab of the spreadsheet but that is an easy operation. Better safe than sorry.

Great, I'll explore the Victron calculator. Thank you!

 

[peak.watt]

Be careful when talking about over-panelling. I've seen some people talk about over-panelling when they are actually talking about creating a situation where in bright sun with a cold panel they will actually exceed their max Voc. Remember that Max Voc is a hard limit.

I've also seen people talking about over-panelling, thinking that their controller will 'just block the current it can't handle' and exceed their max PV short circuit current - this was in a Victron situation. The controller's "Max PV short circuit current" is clearly documented in their spec sheets and is a safety issue (where as max Voc is a "letting the smoke out" issue).

The safe way to over-panel is to ensure your string is below the max Voc of the controller at all times, and doesn't exceed the Max PV Short Circuit current. As mentioned above, the Victron spreadsheet is the easiest way to check this.

 

[pollenface]

I've also seen people talking about over-panelling, thinking that their controller will 'just block the current it can't handle' and exceed their max PV short circuit current - this was in a Victron situation. The controller's "Max PV short circuit current" is clearly documented in their spec sheets and is a safety issue (where as max Voc is a "letting the smoke out" issue).

As stated by others on this forum, this is for short circuit protection (or reverse polarity protection - I can't remember)

 

[kirkdis]

having a 10s2p config on one of my SPF 5000 ES and no issues even in winter but adding soon a 9s2p config to a parallel SPF 5000 inverter so cover as much days in winter.

 

[sparrowhawk]

I have the exact inverter X 2. Each one of them is over paneled with 2,750 watts and in almost 3 years I have never had an issue with them shutting down for any reason. There are times when the inverters show almost 2,200 being used by each inverter. All that being said my VOC is slightly less than 120 volts so it's always below 145 volt limit.

 

[Atetra]

I have the exact inverter X 2. Each one of them is over paneled with 2,750 watts and in almost 3 years I have never had an issue with them shutting down for any reason. There are times when the inverters show almost 2,200 being used by each inverter. All that being said my VOC is slightly less than 120 volts so it's always below 145 volt limit.

Am I missing something here? I checked the specs of this inverter, it can handle pv of 4kw Are these figures you guys quoting over and above of the 4k? Because 2.75kw is if anything undersized.

 

[Supervstech]

Am I missing something here? I checked the specs of this inverter, it can handle pv of 4kw Are these figures you guys quoting over and above of the 4k? Because 2.75kw is if anything undersized.

You may have a 48v model...
The 24v model only has an 80Amp mppt, so 2016 is the max input wattage...

 

[Quankl]

Be careful when talking about over-panelling. I've seen some people talk about over-panelling when they are actually talking about creating a situation where in bright sun with a cold panel they will actually exceed their max Voc. Remember that Max Voc is a hard limit.

I've also seen people talking about over-panelling, thinking that their controller will 'just block the current it can't handle' and exceed their max PV short circuit current - this was in a Victron situation. The controller's "Max PV short circuit current" is clearly documented in their spec sheets and is a safety issue (where as max Voc is a "letting the smoke out" issue).

The safe way to over-panel is to ensure your string is below the max Voc of the controller at all times, and doesn't exceed the Max PV Short Circuit current. As mentioned above, the Victron spreadsheet is the easiest way to check this.

What about controllers(all in ones) which dont state a max PV input current? Like most growatts. Just a max VoC. Does current matter in that acse?

 

[Supervstech]

What about controllers(all in ones) which dont state a max PV input current? Like most growatts. Just a max VoC. Does current matter in that acse?

It often isn't difficult to calculate max input...

They all state max amps.

Say it's a 60A controller.

If you are charging 12V bank, the max pv is going to be just over 900W for 24V it would be 1800W... and so on.

 

[Quankl]

It often isn't difficult to calculate max input...

They all state max amps.

Say it's a 60A controller.

If you are charging 12V bank, the max pv is going to be just over 900W for 24V it would be 1800W... and so on.

The growatt 4-12K DVM MPVs don't have max current input on the spec sheet or manual.

 

[Supervstech]

The growatt 4-12K DVM MPVs don't have max current input on the spec sheet or manual.

There will be a mppt charging rating per pv input.

 

[Supervstech]

Both max mppt charging amps and maximum pv input specs are in the manual.

 

[Quankl]

Both max mppt charging amps and maximum pv input specs are in the manual.

I meant the Growatt 6K, 8K and 12K but this is an example that can work as well. I am looking at this spec sheet for about 10 minutes now I must be really blind or the names are different to what I am looking for.

Max PV Charge Current. - Isnt that only PV charging amps from the inverter at 48V+/- into the battery bank? Which is an adjustable setting within the inverter.

Max AC Charge current - Isnt that only the Grid/Generator input max charging current into the battery bank?

None of those are the PV array input current into the inverter.

Please correct me if im wrong. I find it hard to believe that the growatt allows an 80Amp PV array into the inverter which is why I dont believe that is the spec for the PV array current.

Or is it something I have to calculate manually from the given information on the spec sheet?

 

[Supervstech]

I meant the Growatt 6K, 8K and 12K but this is an example that can work as well. I am looking at this spec sheet for about 10 minutes now I must be really blind or the names are different to what I am looking for.

Max PV Charge Current. - Isnt that only PV charging amps from the inverter at 48V+/- into the battery bank? Which is an adjustable setting within the inverter.

Max AC Charge current - Isnt that only the Grid/Generator input max charging current into the battery bank?

None of those are the PV array input current into the inverter.

Please correct me if im wrong. I find it hard to believe that the growatt allows an 80Amp PV array into the inverter which is why I dont believe that is the spec for the PV array current.

Or is it something I have to calculate manually from the given information on the spec sheet?

The maximum pv array power is the max watts you can attach to the mppt controller.

The maximum pv charge current is the output amps from pv the charger will pump into the battery.

 

[Quankl]

Yes. I understand those but that isnt answering the question about the Max Amps specification that some Charge Controllers / AIO systems have.

Max Input Current Draw as below on the EG4. As in dont have your array go over that current into the MPPT input.

I dont get why its stated by some manufactuers but not others.

 

[Supervstech]

So... 12,960 W max pv input...
Divide the max wattage by the max voltage, and you got the answer.

 

[Quankl]

So... 12,960 W max pv input...
Divide the max wattage by the max voltage, and you got the answer.

Which is what I thought. But in the case of the EG4 above. 7500W max wattage / 500V is 15A. However they rate it at 27A.

And a growatt system we set up. Let's use the 5000w max / 150A. That's 33A. Should that then be correct? If you want to message me directly instead of taking over the thread. I appreciate it.