Growatt SPF 5000 ES Implementation

[Alooma]

I have an installation comprising 16 x 550W Greensun Panels, 2 x Growatt SPF 5000 ES Inverters and 2 x 10kWH LiFePO4 batteries. The batteries are connected using BMS by setting Program 05 to 'L1' and 36 to 'L01'.

I have some issues with the system and trying to investigate the causes.

First, I wish to check if the software version of the inverters is upto date. It is currently showing version as 06 as shown in the attached.

Second, the batteries do not seem to demand enough power from the Solar Panels and the charging rate is low. The current parameters are provided in the attached spreadsheet.

Third, there is a circuit breaker between the solar panels and the PV Combiner Box, could this affect the output of the Solar Power? The overview diagram is attached.

I would appreciate your help, comments and suggestions.

Kind Regards.

 

[timselectric]

Second, the batteries do not seem to demand enough power from the Solar Panels and the charging rate is low. The current parameters are provided in the attached spreadsheet.

When using BMS communications, you give charging control to the BMS. Whatever the battery manufacturer set it to do. It is what it is.

Third, there is a circuit breaker between the solar panels and the PV Combiner Box, could this affect the output of the Solar Power? The overview diagram is attached.

If it's a good quality breaker, it won't affect the output in any noticeable amount.

 

[Alooma]

When using BMS communications, you give charging control to the BMS. Whatever the battery manufacturer set it to do. It is what it is.

If it's a good quality breaker, it won't affect the output in any noticeable amount.

Thanks Tim.

But why am I getting less than a quarter of the solar power. Does any one know why with the above settings?

Kind Regards.

 

[LydMekk]

This time of year it is NORMAL with only around 25%-35% of max due to clouds, weather, long distance from the sun etc. Numbers will be different in summer.
Also: you never get max of rated panel power and also never more than your loads ask for.

 

[timselectric]

As stated above. It's a bad time of year for solar production. Also your BMS's may not be asking for much amperage. I'm not a fan of communications between BMS's and chargers. You never know if it is working correctly, because you don't know what it should be doing. I use my own parameters and easily know when something is off.

 

[Alooma]

This time of year it is NORMAL with only around 25%-35% of max due to clouds, weather, long distance from the sun etc. Numbers will be different in summer.
Also: you never get max of rated panel power and also never more than your loads ask for.

Thanks for your response. The installation is in Lagos and currently having about 5 sunlight hours with no clouds. Please, refer to the attached for the expected output.

 

[Alooma]

As stated above. It's a bad time of year for solar production. Also your BMS's may not be asking for much amperage. I'm not a fan of communications between BMS's and chargers. You never know if it is working correctly, because you don't know what it should be doing. I use my own parameters and easily know when something is off.

Thanks for your response. I am not sure that it is the BMS. I have occasions when the batteries are fully charged with SOCs around 99%, and the solar power for the loads get supplemented by the batteries on reaching about 1600W.

Each panel has a Vmp of 31.6V and Imp of 17.4A. They are connected in series of 8 panels to each inverter. The PV Voltage taken from ShinePhone is attached. It shows voltage close to 280V and thus expecting the kWH to be about 280 * 17.4 = 4.8kWH, and with sunlight hours oof about 5 hours, I should be getting about 22kWH per day and not 10kWH.

 

[timselectric]

Thanks for your response. I am not sure that it is the BMS. I have occasions when the batteries are fully charged with SOCs around 99%, and the solar power for the loads get supplemented by the batteries on reaching about 1600W.

It really sounds like the BMS is limiting charging.
What does the BMS have settings #19 and #20 at?

 

[Alooma]

I had programs 02 set to SUB and 05 set to L1. This morning the batteries had SOCs of about 61% and when Grid was restored, the batteries were not charging fast enough. I changed program 05 to USE, with 19 set to 56V, 20 left at default of 54V and 21 set to 40V. The charging was still slow. I then decided to bypass the inverter from providing Loads into the house, this resulted in faster charging of the batteries. Batteries have gone from 61% to over 72% in abut 30 minutes.

Please, refer to the attached. 2190W going into charging the batteries from Master Inverter and 2275W from the Slave. Meanwhile, it is 10:37 in Lagos, and the Amperes from the Panels is 1.6A.

Another question, what is the recommended wire specification for connecting solar panels? The local engineer suggested 10mm instead of 4mm. Could the wires be the cause the low Amperes. The distance from panels to Inverter is about 10 metres.

 

[nezek88]

Its setting 02, your charge current is on 25a according to your spreadsheet.
Set it to a 100 or to the maximum your battery allows.

 

[Alooma]

Thanks for your response. This was changed to 100A when using program USE but BMS set it when it the program is on L1. While on L1, I notices that it kept being changed by the BMS to 100A depending on the batteries SOCs, and then to 50A and then 25A as the SOC approaches 95%.

 

[Alooma]

UPDATE.

I got someone to get to the roof and shoot the video of the panels. I found out that they are very dusty - installed about 3 months ago. I wanted to get someone to help clean them with water, but fortunately, it rained last night. This morning, my Solar Power generation went up to 23kWH for the day, and was able to get the Amperes upto 9A midday from the previous maximum of 2.3A.

I will continue monitoring.

Meanwhile, I think that if the panels are properly cleaned, I could get nearer to the expected 31kWH per day at this time of the year.

 

[Olasitu]

Hello @Alooma .. Something to note. As long as you have PV you cant charge from Grid. The only way to accelerate charging from the Grid is to turn off the PV. Even though the setting is SNU. It's not Solar and Utility at the same time. @timselectric explained this quite well in one of my previous posts. At least I think that what was explained. Your screenshots however implies you are charging from Grid and Solar. @timselectric please help out here ?

 

[timselectric]

Hello @Alooma .. Something to note. As long as you have PV you cant charge from Grid. The only way to accelerate charging from the Grid is to turn off the PV. Even though the setting is SNU. It's not Solar and Utility at the same time. @timselectric explained this quite well in one of my previous posts. At least I think that what was explained. Your screenshots however implies you are charging from Grid and Solar. @timselectric please help out here ?

You can charge from both, as long as you are not inverting from the battery. (Bypass relay engaged)
The inverter/charger board does both inverting and AC charging. It cannot work in both directions at the same time.