Growatt 12k unboxing

[Jgb3]

@Jgb3 How's those bms units working out? I'm about to start the exact project for an off grid home.

Biggest issue is the BMS units I wanted to use from overkill solar. I want to use 32 280 cells 16s, each 16s group with its own bms. Then parallel the 2 packs.

But the BMS from overkill are only 100amp x 2 and 48vdc x 200amp = 9600 watts. So I would shut down at 9600w ... Unless I build a 3rd 16s bank with a third bms, which I may do.

Been awhile since I’ve been on here but the Daly bms’s I got sucked one was junk and Daly made me ship it to them and pay for return shipping so they could fix it even though they sent me a junk bms. I’ve purchased a jbd bms 300amp but haven’t had a chance to install it yet

 

[Jgb3]

@Jgb3 what did you end up for an array size and wiring? I was thinking 5s4p of 350w panels for 7000 watts
... Then add a 5th string of 5 more (5s5p) to over panel due to losses and clouds.

Well the growatt has 2 inputs so I went with 3s4p x 2 so 24 335 watt panels 8040 watts

 

[Jgb3]

@Jgb3 what did you end up for an array size and wiring? I was thinking 5s4p of 350w panels for 7000 watts
... Then add a 5th string of 5 more (5s5p) to over panel due to losses and clouds.

Also over paneling is only on the watts side don’t go over on the volts. They have calculators to factor in temperature. I haven’t looked but I’m sure you have to be close or over with that set up you don’t want to have a cold sunny day and fry your controller

 

[MrM1]

@Jgb3 thanks for the feedback

 

[MrM1]

@Jgb3 What displays are those next to the Daly BMS units. And what Victron Smart Shunt are you using? 500amp?

 

[BMcL]

Also over paneling is only on the watts side don’t go over on the volts. They have calculators to factor in temperature. I haven’t looked but I’m sure you have to be close or over with that set up you don’t want to have a cold sunny day and fry your controller

Any updates on how you're system is running ?

 

[Ironman]

I don't know what to tell you on that, others will be able to help. I am still a bit concerned about only being able to hook 7000 watts to it. I have seen the explanation, but wonder why they call it a 12,000 watt unit?

The Growatt 12000T will stand a surge of up to 15KW for starting current. You are confusing input with output. All inverters quote output and surge power.
The input is as stated 7000 watt solar, and they can be over paneled without harm. The over paneled watts will be wasted in summer and desperately needed in winter. Growatt has 2 solar input circuits and handles 120 amps maximum in two strings of 60 amps on each solar input. I recall the voltage on mine is 146 volts PV input and if they raised that it would be a good thing.
I would advise you to call Ian at watts247.com for more info, he is a good man to deal with.
EDIT: The Growatt is the 3rd largest selling inverter worldwide, I am told. It does not have the approval of the bureaucrats so no UL or CSA stickers. This does not matter to most of the DIY crowd, but adhering to recognized good wiring practices and wire sizes is important.

 

[MrM1]

OverPaneling

This from Signature Solar as an email to me As to OverPaneling the Growatt SPF 12kW DVM MPV 250VDC and how the two PV inputs work for the MPPT SCC (PV1 and PV2).

(Me) Page 10 of the Manual - Indicates There are 2 PV input connections for the 12k version, but there is very little or no explanation of why or how they are used. I assume this has to do with MPPT tracking? Are there MPPT settings in the charge controller section of the control parameters? Not finding much about this or Array arrangement.
These models are essentially 2 6kw units combined into one. Each MPPT controller can handle 7000W from the array and the settings will be determined by total input.

(Me) We want to over panel the setup, but the manual in the specs only lists the inverter is rated for a 7000w array. Why is this a limitation? If we keep the array input under 250vdc wouldn't any over current just simply not be used? We would like to over panel because we have seen about a 15% drop off in rated power from an array on average here in FL on other off grid systems. Would like to build out a 8000w or 10,000w array for cloudy days, and to maximize power harvest in the mornings and afternoons.
As long as you do not exceed the VOC/VDC you can have more than 7000W of power generated from your panels, however it will not be inverted so it will be wasted.

 

[AlbaCORPS]

OverPaneling

This from Signature Solar as an email to me As to OverPaneling the Growatt SPF 12kW DVM MPV 250VDC and how the two PV inputs work for the MPPT SCC (PV1 and PV2).

(Me) Page 10 of the Manual - Indicates There are 2 PV input connections for the 12k version, but there is very little or no explanation of why or how they are used. I assume this has to do with MPPT tracking? Are there MPPT settings in the charge controller section of the control parameters? Not finding much about this or Array arrangement.
These models are essentially 2 6kw units combined into one. Each MPPT controller can handle 7000W from the array and the settings will be determined by total input.

So from the responses you got, you can in essence run up to 14kW as long as its 7kW per array input ?

 

[MrM1]

So from the responses you got, you can in essence run up to 14kW as long as its 7kW per array input ?

That would be my understanding from that response. But from the larger body of info I have been gathering from multiple discussions on the forum, emails and from midnight solar indicates it really does not seem to matter how big the array is as long as it does not exceed the input VOC of the SCC . The extra will not be dissipated as heat, the SCC just simply will not use it. So it's up to the individual to decide how much Overpaneling waste they want to design in

In our case we plan to design in such a way that we will have 2 arrays and if we find our need for charing is greater than our waste, we'll simply add a second SCC and break the 2 arrays into 3.

My understanding of the Growatt 12K inverter is that it is only going to produce 60 amps of charge current per PV input. So anything more than that will be waste. But the idea of waste is somewhat of a subjective concept. It's not wasted if it produces near full capacity on a partially cloudy day or in the morning or early afternoon. In my opinion.

 

[MrM1]

Today my 2565w array is producing 88 watts (raining) . Is it a waste to double the size of that array so that I would be producing 176 watts? Or that it might produce 1800 watts on a partly cloudy afternoon where before I increased the size it might only produce 1000 watts? Not for my needs.

 

[kromc5]

It would be better to add charge controllers than overpaneling to much, I stopped at 18 500w panels for each inverter / charge controller.

 

[AlbaCORPS]

. MrM1 It appears we're in the spot (choices of inverters, wants & needs ?)

 

[MrM1]

It would be better to add charge controllers than overpaneling to much, I stopped at 18 500w panels for each inverter / charge controller.

I would tend to agree with this, but a 2nd charge controller will always require more panels, but extra panels may not require a second charge controller. Which leads me to my conclusion. Over panel first and if it meets my needs save on the SCC, but if it does not, then I am already ready for the second SCC

 

[kromc5]

I would tend to agree with this, but a 2nd charge controller will always require more panels, but extra panels may not require a second charge controller. Which leads me to my conclusion. Over panel first and if it meets my needs save on the SCC, but if it does not, then I am already ready for the second SCC

If you can manage to slightly over panel and stay positive that would be cheaper. But amazingly even 5 500w panels can hit 20 amps on the charge controller in perfect weather. I started out slightly over paneling by 3000w on the inverter but found out the charge controllers even if under paneled really help out in poor weather. Perfect days the inveter could get the batteries to the charge cut off, but the charge controllers really take the charge/discharge off the batteries and greatly help on cloudy days.

 

[MrM1]

If you can manage to slightly over panel and stay positive that would be cheaper. But amazingly even 5 500w panels can hit 20 amps on the charge controller in perfect weather. I started out slightly over paneling by 3000w on the inverter but found out the charge controllers even if under paneled really help out in poor weather. Perfect days the inveter could get the batteries to the charge cut off, but the charge controllers really take the charge/discharge off the batteries and greatly help on cloudy days.

So do you have more than 1 Growatt All in One inverter or more than 1 charge controller... Or are you referring to the 2 charge controllers (PV1 & PV2 input) on the one Growatt?

How much over panel did you do? 500x18 for the total (4500w on each PV input), OR 9000w on each input for a total of 18000w

 

[MrM1]

It would be better to add charge controllers than overpaneling to much, I stopped at 18 500w panels for each inverter / charge controller.

So do you have more than 1 Growatt All in One inverter or more than 1 charge controller... Or are you referring to the 2 charge controllers (PV1 & PV2 input) on the one Growatt?

How much over panel did you do? 500x18 for the total (4500w on each PV input), OR 9000w on each input for a total of 18000w

 

[kromc5]

So do you have more than 1 Growatt All in One inverter or more than 1 charge controller... Or are you referring to the 2 charge controllers (PV1 & PV2 input) on the one Growatt?

I'm running two 12kwh inverters and 4 charge controllers. I started out testing slowly and found that adding more panels beyond 15 did not yield alot more production. It appears for at least my growatts that the scale of production by adding panels goes down very quickly. Moving the panels to charge controllers provided much more output.

 

[kromc5]

So do you have more than 1 Growatt All in One inverter or more than 1 charge controller... Or are you referring to the 2 charge controllers (PV1 & PV2 input) on the one Growatt?

How much over panel did you do? 500x18 for the total (4500w on each PV input), OR 9000w on each input for a total of 18000w

I have 18 panels for each inverter on pv1 input for the inverters.

 

[MrM1]

Sorry I was editing and you might have missed the 2nd part of my question

It would be better to add charge controllers than overpaneling to much, I stopped at 18 500w panels for each inverter / charge controller.

How much over panel did you do? 500x18 for the total (4500w on each PV input), OR 9000w on each input for a total of 18000w

 

[MrM1]

I have 18 panels for each inverter on pv1 input for the inverters.

Are you not using pv2

 

[kromc5]

Are you not using pv2

Not using pv2 on the inverters, I had asked signature about this but said it would be fine for pv1 at 18 panels.
Slightly cloudy so not make the full amount, inveter and two charge controllers, load is right at 14 amps as well.

 

[MrM1]

So do you get a full 120 amps of charging or do you only see 60 amps of charging. My understanding is that each PV input only has 60 amps each side for a total of 120 amps if you use both.

 

[kromc5]

So do you get a full 120 amps of charging or do you only see 60 amps of charging. My understanding is that each PV input only has 60 amps each side for a total of 120 amps if you use both.

I have wondered about this as well, none of the inverters or charge controllers have yet to get anywere near the rated output. Seems like 48 amps is the max I have seen.

 

[MrM1]

I think that is because yours only using 1 of the 2 PV inputs. I was told there are actually 2 SCCs in the big growatts. And that to get full capacity u must use both