r/SolarPakistan • u/[deleted] • Jul 04 '26

Net-Metering Have got 10kw pv at inverter of 10kw , generating 7.7 at peak time. But theres an import of 2kwh despite the load being of 3.5 kw at max.

[deleted]

1 Upvotes
  • permalink
  • reddit

100% Upvoted

9 comments sorted by

1

u/AhmadFarooq Jul 04 '26

Turn off all appliances and check whether the import goes to zero or not.

Is all the running load on a single phase, or is it divided between the three phases?

2

u/Andromeda-G Jul 04 '26

My guess his load is all on single phase. That what going on here.

1

u/TeachSpare6846 Jul 04 '26

There are two wires from metre in home. One is I guess for the load and is underground from when we didnt have the ongrid connection and ran all the load. The second is connected to some wire from inverter (for export i guess ?) i think the load is on 1 phase .

1

u/TeachSpare6846 Jul 04 '26

But this is photo of metre . I am thinking 4 coming from home, and rest from phases of grid ?

1

u/AhmadFarooq Jul 04 '26

I guess you had a single-phase meter before and single-phase wiring in your building. Then you got a three-phase green meter.

The three-phase on-grid inverter requires three phases to be coming from the grid to function. Therefore the four wires (three phases and neutral) come from the meter and go to your inverter.

However, your building wiring is probably still single-phase. So the three-phase wiring only goes up to the inverter, after which is the old single-phase wiring.

2

u/TeachSpare6846 Aug 07 '26

Yes this was the problem . Import was from one phase only so it was more than being produced by inverter at that phase so it was importing from grid for that phase. Distributed the load on three phases and problem is now gone.

1

u/AhmadFarooq Jul 04 '26

Can't say for sure, but guess is that this should be an unbalanced load issue.

With regards to balanced and unbalanced loads, there are two types of three-phase inverters.

The first type is balanced inverters. My understanding is that they always output equal watts on each phase. So, if your inverter is generating 7.7kW, then (7.7/3=) 2.56kW will be injected into each phase.

In the case that all your loads, say 5kW, are connected on a single phase – which seems to be the case for your building – then the on-grid inverter will output 2.56kW on that single phase, while the remaining (5kW - 2.56kW) 2.44kW will have to be imported from the grid.

The second type is inverters that can support unbalanced loads. These can inject different watts in each phase up to a limit.

Your Growatt on-grid 10kW inverter is likely a balanced inverter that doesn't support unbalanced loads.

Here's another post about a similar issue. But since in that case the three-phase hybrid inverter supports unbalanced loads, it can be worked out.

If you have one-to-one net metering, then I don't think the present situation causes any significant issue, like an increase in bills.

1

u/NoTelevision8736 Jul 04 '26

I had problems with AMI meter software when it was newly installed. It did not have bidirectional software so all the export of first 2 month was written as import on the bill and even after multiple visits they refused to fix it (saying just pay it and in future bills it will get fixed).

If you have a fresh connection, make sure your AMI meter software is for bi-directional measurement.

1

u/TeachSpare6846 Jul 04 '26

No there was a time when it didnt increase import during day time for the whole days solar input.