Do i need a 3 phase solar inverter with 3 phase power ?

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My home has a 3 phase power and i am going for 6.6 kw solar connection with 5 kw three phase inverter. 

The solar company is advising me that i can go with single phase inverter as the new solar smart meters are programmed in such a way that it records the consumption across all there phases. 

See attached info shared with me. 

Is this how the solar smart meter of AGL works ?

Would you recommend that i can go with single phase inverter?






0 Replies 3664 Views

Hi Jayden,


This is correct in how AGL work out the export but a single phase inverter on a three phase property is not a good idea as loads are not balanced as required.



2 Replies 2900 Views

Thank you for explaining this. 
Does this mean I will be billed for the net amount drawn from the grid not the actual amounts drawn?


What confused me is that I have read if you have a single phase inverter with a 3 phase dwelling, ( taking your example) the utility provider will charge you for phase 2 and 3 energy drawings and give credit to excess uploaded in solar phase 1.  I think your previous answer clarified this but I want to be 100% sure. 


Sorry if you have to repeat what you explained.



1 Reply 2898 Views

Hi Mjuice,


You will only be charged for what you draw from the grid.


The charging by the utility only occurs after the netting of the three phases at the meter has occurred.  A feed-in-tariff credit only occurs if the solar generated exceeds the draw at the household. If Phase 2 and 3 are drawing 2 kWh and your Solar is only generating 1 kWh, you would be drawing 1 kWh from the grid.


It would probably help to think of it as summing the three phases and asking yourself what the total is.  If you have more solar generated than what is being consumed in the household, then that is your feed-in-tariff. If you have more consumed in the household than solar is generating, then that is what you are drawing from the grid.


For the purpose of your billing, you would need to assume that a three phase is being treated as one big single phase to make the math easy.





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0 Replies 2888 Views

Thank you very much, this clarifies a lot. Have a great day.


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The polyphase meter works it out, so you are only charged for total imports after solar contribution to grid. 
This is why it was pointless to put solar on a “quiet” phase during the era of high feed in tariff in QLD it didn’t mean you exported more as the polyphase

meter works out total import and total export.