Solar system. Trying to work out whether to use 3 phase or 1 phase for a hybrid grid tied inverter

[MoreWellie]

For a site with a 3 phase supply should you choose a 3 phase inverter? If the loads aren't balanced (a large amount of equipment is single phase) would it be better to use a single phase inverter on the phase that has the highest usage

Does anyone have enough experience of 3 phase inverters to say how well they work with unbalanced loads?

I have looked at specs for Solax, Fox and Solis but cannot see anything that says how good they are with unbalanced loads or whether a 3 phase inverter will just be wasting power

 

[wobblie]

I have a Solax 10kw 3 phase inverter.
Our house currently only uses one phase so the load is unbalanced.

The Solax inverter has a setting to allow for unbalanced loads: if it's not set, it will send power to all three phases equally, so two thirds of the power is sent to the grid irrespective whether you could use it.
Once unbalanced setting is turned on, if one phase requires 10kw, the inverter will send all the power to that phase before the battery or to the grid.(Depending on charging settings etc)

It works well for us.

One advantage of a 3 phase inverter is that the DNO is likely to allow you higher export limit to the grid (we have 10kw export limit)..... just repeating what I was told here.....

I don't know anything about the other two inverters you mentioned

Hope that helps

 

[brewdexta]

With a G98 connection, where you don't need DNO permission or survey, just notify them and meet the G98 requirements, you can export up to 16 amps per phase. So with a 3 phase inverter you could export 3 times the single phase amount.

 

[minimutly]

I have a Solax 10kw 3 phase inverter.
Our house currently only uses one phase so the load is unbalanced.

The Solax inverter has a setting to allow for unbalanced loads: if it's not set, it will send power to all three phases equally, so two thirds of the power is sent to the grid irrespective whether you could use it.
Once unbalanced setting is turned on, if one phase requires 10kw, the inverter will send all the power to that phase before the battery or to the grid.(Depending on charging settings etc)

It works well for us.

One advantage of a 3 phase inverter is that the DNO is likely to allow you higher export limit to the grid (we have 10kw export limit)..... just repeating what I was told here.....

I don't know anything about the other two inverters you mentioned

Hope that helps

That's really interesting. I had a 3 phase system (9kW) put in at our club. It turned out the load is anything but balanced. I had looked at a battery system to absorb and feed back on the high load phase - the option to do this in the inverter was not one I knew about - looks like I need to find out...

 

[MoreWellie]

The Solax inverter has a setting to allow for unbalanced loads

Thank you, just what I wanted to know