Growatt SPH and Power import control from grid

[amico23]

Hi All,

i have a Growatt SPH4600 Inverter with 8,375kWp solar panels and a 5kWh LiFePo4 battery.
The communication with the Growatt TPM works (telephone symbol in the display).
Communication with the battery is via CAN and works well (SOC and battery voltage).

Now to my problem:

If the energy from the PV system is no longer sufficient in the evening/night to supply the load in the house, the missing required energy from the battery. The inverter attempts to control the to export power / import power to 0 watts.
But that often doesn't work. The SPH4600 almost always gets over a longer period of time about 20 - 50 watts from the grid, although the battery had enough energy.

Can I change the value in the SPH4600 in the settings or register that no longer to control 0 watts but, for example
regulated to -50 watts (export power). It is better to always export a bit to grid then to import from grid.

Thanks in advance for any tip

 

[Eldaniel1910]

Hi, did you find solution to this issue please? I am having exactly the same problem. It is not a major issue but through this trickle import it is using up to 1kW from the grid when my daily usage is about 10kW so quite a big percentage of energy which I should not be importing as my battery is never below 80% as it has been decent weather since install. Sometimes it will show i.e. 0.12 import when solar PV producing much more that and battery is close to full capacity. Just to add, this imported energy is rarely used to charge a battery.
As you can see on the attached screenshot (ignore 19:30 because can only provide max 3kw at any given time) it shows not only unnecessary import but also export. Why would it export it when it is not generating anything? In settings - AC charging is on but no times have been set to force charge the battery. Any help would be appreciated. Thanks

 

[Cheap 4-life]

Hi All,

i have a Growatt SPH4600 Inverter with 8,375kWp solar panels and a 5kWh LiFePo4 battery.
The communication with the Growatt TPM works (telephone symbol in the display).
Communication with the battery is via CAN and works well (SOC and battery voltage).

Now to my problem:

If the energy from the PV system is no longer sufficient in the evening/night to supply the load in the house, the missing required energy from the battery. The inverter attempts to control the to export power / import power to 0 watts.
But that often doesn't work. The SPH4600 almost always gets over a longer period of time about 20 - 50 watts from the grid, although the battery had enough energy.

Can I change the value in the SPH4600 in the settings or register that no longer to control 0 watts but, for example
regulated to -50 watts (export power). It is better to always export a bit to grid then to import from grid.

Thanks in advance for any tip

Sounds like you are using limit to home mode/export control. The inverter will allow the grid to supply some of the load (the 20-50w you mention) so the inverter isn’t backfeeding into the grid. I’m not familiar with the growat but you can probably turn off limit to home and the inverter will then backfeed into the grid but will probably backfeed everything it can unless you turn off setting that allows battery to go into the grid at all, that’s if growatt has that option

 

[pdchristy]

Did you get anywhere with resolving this. I have the same issue, small import constantly when the system isn't exporting and then around 9pm it also pretty consistently needs to import 2-300w despite only a very small load (700w) on the system. Likewise, I'm importing 0.5-1kwh per day, which is annoying and changes the ROI quite a lot, and I'm concerned that through the winter the problem will be more significant.

 

[Cheap 4-life]

Hi All,

i have a Growatt SPH4600 Inverter with 8,375kWp solar panels and a 5kWh LiFePo4 battery.
The communication with the Growatt TPM works (telephone symbol in the display).
Communication with the battery is via CAN and works well (SOC and battery voltage).

Now to my problem:

If the energy from the PV system is no longer sufficient in the evening/night to supply the load in the house, the missing required energy from the battery. The inverter attempts to control the to export power / import power to 0 watts.
But that often doesn't work. The SPH4600 almost always gets over a longer period of time about 20 - 50 watts from the grid, although the battery had enough energy.

Can I change the value in the SPH4600 in the settings or register that no longer to control 0 watts but, for example
regulated to -50 watts (export power). It is better to always export a bit to grid then to import from grid.

Thanks in advance for any tip

Do you have this inverter wired to the main panel of your home? I mean the actual AC output of this inverter. Is it supplied directly to your homes main panel or is it through a critical loads panel

 

[Cheap 4-life]

Did you get anywhere with resolving this. I have the same issue, small import constantly when the system isn't exporting and then around 9pm it also pretty consistently needs to import 2-300w despite only a very small load (700w) on the system. Likewise, I'm importing 0.5-1kwh per day, which is annoying and changes the ROI quite a lot, and I'm concerned that through the winter the problem will be more significant.

I use GTIL2 limiting inverters that limit their output using Cts. When homes loads are really low (below 300w) the inverters tend to allow the grid to supply more like 50w instead of the usual 14w. I think this is done to prevent backfeeding into the grid when loads are low. But I’m not seeing 300w from the grid or I’d have to do something about it. However when the washing machine is running the GTIL2 can’t see that load fast enough because washing machines turn on/off rapidly. When using the washing machine I hav3 seen the grid supplying 200w. Is your washing machine running when you are seeing the 300w import?

 

[pdchristy]

I use GTIL2 limiting inverters that limit their output using Cts. When homes loads are really low (below 300w) the inverters tend to allow the grid to supply more like 50w instead of the usual 14w. I think this is done to prevent backfeeding into the grid when loads are low. But I’m not seeing 300w from the grid or I’d have to do something about it. However when the washing machine is running the GTIL2 can’t see that load fast enough because washing machines turn on/off rapidly. When using the washing machine I hav3 seen the grid supplying 200w. Is your washing machine running when you are seeing the 300w import?

No, the TV and amp were both on, but they were the rest of the evening. I read a comment elsewhere suggesting that the growatt inverters do some sort of test at dawn and dusk which means they import more than they do the rest of the time (seems a bit stupid), but it's also consistently out by a factor, see screenshots of actual import from octopus and perceived import by the inverter.

 

[Cheap 4-life]

No, the TV and amp were both on, but they were the rest of the evening. I read a comment elsewhere suggesting that the growatt inverters do some sort of test at dawn and dusk which means they import more than they do the rest of the time (seems a bit stupid), but it's also consistently out by a factor, see screenshots of actual import from octopus and perceived import by the inverter.

I’m not seeing any totals for consumption in the second pic. Maybe get an
Iotawatt to better see what’s going on with your system. It has very accurate power monitoring and much better graphing than the pics you jus5 posted

 

[pdchristy]

Thanks, I'll have a look at iotawatt. Weirldly the shine app isn't showing the import data for that day, but figures from the earlier days as follows:

date	inverter monitoring import	actual import from supplier
18/7	0.6	0.66
17/7	0.3	0.48
16/7	0.4	0.43
15/7	0.2	0.53

Nothing of any real load switched on at all, there's a lump at dusk, which might be this self-test I've read about (still not very good) and the rest is a trickle through the night, when it seems to be not using the batteries enough.

 

[Cheap 4-life]

Thanks, I'll have a look at iotawatt. Weirldly the shine app isn't showing the import data for that day, but figures from the earlier days as follows:

date	inverter monitoring import	actual import from supplier
18/7	0.6	0.66
17/7	0.3	0.48
16/7	0.4	0.43
15/7	0.2	0.53

Nothing of any real load switched on at all, there's a lump at dusk, which might be this self-test I've read about (still not very good) and the rest is a trickle through the night, when it seems to be not using the batteries enough.

My GTIL2s slowly allow the grid to supply more of the load as the battery voltage gets lower. Could this possibly be what your seeing with the growatts?

 

[pdchristy]

I don't think so, the battery isn't dropping to even 80% overnight and the rate is flat (ie pretty constant trickle in from the grid).

 

[shaunuk]

same problem, put a clamp meter on the incoming live and I see 1.2a most the time, I think the issues is the ct clamp is not accurate, my house is pulling about 150w from the grid when the load in the house is low, if I switch on something with a load like a 2kw vacuum cleaner the inverter will get the grid import down to 0w.

Apparently swapping out the ct clamp for a din rail meter like this: https://www.alternergy.co.uk/eastron-1ph-energy-meter will sort out the accuracy.

its not even mid day and I have already imported over a kwh due to this silly design. 2kwh per day this winter when energy will be 40p+ will be 80p a day, almost £300 a year, thats another two solar panels paid for.... who actually thinks this is ok? I would rather run off grid and limited to 3kw battery output over night than pay this stupidity. Will post back when I swap to a meter, if it doesn't work im going off grid, screw Putin and his cheap gas running most of Europe. Im fighting back

 

[pdchristy]

I made exactly that change last week. I've 4 days of results and I'm down to c. 0.09kwh usage per day now (measured by my supplier) vs. 0.6-0.8kwh prior to the switch to the meter. It's much better albeit not 100% perfect. I think probably as good as it possibly can be though now. We have been away for a couple of days, so it's possible the change won't be as distinct when we're here, but it was still drawing from the grid the last time we were away. Amazon have the meter if you can't be bothered trying to get altenergy to approve you an account (mine is still waiting)

SDM230 Modbus V2 RS485 Single Phase, Energy Meter, Electricity Usage Monitor, 100 Amp kWh Din Rail Power Meter, Pulse Meter, Modbus RS485 RTU. Digital Backlit LCD Display. MID Certified : Amazon.co.uk: DIY & Tools

Free delivery and returns on all eligible orders. Shop SDM230 Modbus V2 RS485 Single Phase, Energy Meter, Electricity Usage Monitor, 100 Amp kWh Din Rail Power Meter, Pulse Meter, Modbus RS485 RTU. Digital Backlit LCD Display. MID Certified.

www.amazon.co.uk

Just to note that the pins have changed on the V2 vs the Growatt manual. Follow the drawing on the side of the SDM230

Now has anyone got any ideas on the stupid reset calibration at dusk?? I've not got the data yet to see if the meter has fixed that too

 

[shaunuk]

I made exactly that change last week. I've 4 days of results and I'm down to c. 0.09kwh usage per day now (measured by my supplier) vs. 0.6-0.8kwh prior to the switch to the meter. It's much better albeit not 100% perfect. I think probably as good as it possibly can be though now. We have been away for a couple of days, so it's possible the change won't be as distinct when we're here, but it was still drawing from the grid the last time we were away. Amazon have the meter if you can't be bothered trying to get altenergy to approve you an account (mine is still waiting)

SDM230 Modbus V2 RS485 Single Phase, Energy Meter, Electricity Usage Monitor, 100 Amp kWh Din Rail Power Meter, Pulse Meter, Modbus RS485 RTU. Digital Backlit LCD Display. MID Certified : Amazon.co.uk: DIY & Tools

Free delivery and returns on all eligible orders. Shop SDM230 Modbus V2 RS485 Single Phase, Energy Meter, Electricity Usage Monitor, 100 Amp kWh Din Rail Power Meter, Pulse Meter, Modbus RS485 RTU. Digital Backlit LCD Display. MID Certified.

www.amazon.co.uk

Just to note that the pins have changed on the V2 vs the Growatt manual. Follow the drawing on the side of the SDM230

Now has anyone got any ideas on the stupid reset calibration at dusk?? I've not got the data yet to see if the meter has fixed that too

super info, thanks !

Ive ordered that meter, will give it a go tomorrow, what's this reset business ?

 

[pdchristy]

Apparently at dawn and dusk the inverter does some sort of reset/test/calibration thing which in my house leads to about a 300w draw around 9pm (July). Need to check if it's still doing it having swapped to the meter. I found a thread saying growatt support say it's expected behaviour.

 

[shaunuk]

I made exactly that change last week. I've 4 days of results and I'm down to c. 0.09kwh usage per day now (measured by my supplier) vs. 0.6-0.8kwh prior to the switch to the meter. It's much better albeit not 100% perfect. I think probably as good as it possibly can be though now. We have been away for a couple of days, so it's possible the change won't be as distinct when we're here, but it was still drawing from the grid the last time we were away. Amazon have the meter if you can't be bothered trying to get altenergy to approve you an account (mine is still waiting)

SDM230 Modbus V2 RS485 Single Phase, Energy Meter, Electricity Usage Monitor, 100 Amp kWh Din Rail Power Meter, Pulse Meter, Modbus RS485 RTU. Digital Backlit LCD Display. MID Certified : Amazon.co.uk: DIY & Tools

Free delivery and returns on all eligible orders. Shop SDM230 Modbus V2 RS485 Single Phase, Energy Meter, Electricity Usage Monitor, 100 Amp kWh Din Rail Power Meter, Pulse Meter, Modbus RS485 RTU. Digital Backlit LCD Display. MID Certified.

www.amazon.co.uk

Just to note that the pins have changed on the V2 vs the Growatt manual. Follow the drawing on the side of the SDM230

Now has anyone got any ideas on the stupid reset calibration at dusk?? I've not got the data yet to see if the meter has fixed that too

Done and working. The ct clamp is gone and the meter is installed And it’s so much better often the in-home display shows zero now as opposed to 150w with the rubbish clamp, sometimes it fluctuates out for a few seconds, but then comes back under control. Usually when a load is starting or stopping.

 

[pdchristy]

Good that you've found the same benefit too. Daft that it isn't the default option

 

[shaunuk]

Yes. very daft. Now I would like more batteries. 13kwh was plenty but some one gave us a hot tub and it can drain them in 4 hours.
They seem to be much better value in the us and china. Best price I can find is £1600 for 5.2kwh server rack format. But they send the components and I would need to pick them up from a port.

 

[Gammeltoft]

Hi There, funny, as i have the excact same problem with a 10kW Growatt inverter and the mentioned smart meter.
Has contacted the company from whom i bought the plant. Answer is that its because i have had accessed the inverter myself.....
Even the problem has persisted from day 1, where i was not logged in to the inverter via the Shine app.....
Its getting annoying as there is no response at all from Growatt either..... considering scrapping the inverter.......

 

[shaunuk]

Hi There, funny, as i have the excact same problem with a 10kW Growatt inverter and the mentioned smart meter.
Has contacted the company from whom i bought the plant. Answer is that its because i have had accessed the inverter myself.....
Even the problem has persisted from day 1, where i was not logged in to the inverter via the Shine app.....
Its getting annoying as there is no response at all from Growatt either..... considering scrapping the inverter.......

dont give up, get your self a meter and dump the rubbish ct clamp, the amazon link above the the correct one, works great and its only £50/$55 ish. Good hardware bad support.... just use the community for help, not their support line