Feeding back into grid.

[Derlyn]

Help me understand.

One can, with a special meter, and the right setup, feed excess power generated by your panels, back into the grid.

Your inverter however must stop feeding back into the grid, should the Supply Authority switch off the grid for maintenance purposes.

How will your inverter know when to stop exporting if there are multiple inverters exporting simultaneously ?

How does your inverter distinguish between grid power and power exported into the grid from other inverters ?

[GCE]

Inverters look for grid - if they do not see grid they turn off and just watch for grid to come back - in simple terms
They cannot reconnect to grid unless they see grid for at least 60 seconds and that the grid is stable/complies

Multiply inverters will all drop out when grid drops and wait for 60 seconds to ensure grid is stable

[Derlyn]

Inverters look for grid - if they do not see grid they turn off and just watch for grid to come back - in simple terms
They cannot reconnect to grid unless they see grid for at least 60 seconds and that the grid is stable/complies

Multiply inverters will all drop out when grid drops and wait for 60 seconds to ensure grid is stable

Hi GCE

I still don't understand.

Let's say there are 10 inverters exporting to the grid.
Your inverter is one of them.
Now the Municipality switches off to do maintenance.
How does your inverter know that the grid has been turned off, when there are the other 9 inverters feeding into the grid.

What prevents the inverters that are feeding the grid from seeing each other as the grid ?

[GCE]

Inverters cannot create a grid - they can only follow a grid - if the grid drops they drop
In other words they need to see a grid - if for a micro second the grid is not there they drop out and wait for grid

[Justloadit]

What also occurs, when the grid goes down, due to the low impedance of the grid, the amount of energy fed back by the inverter will surpass the inverter maximum current, and as this happens, it goes into islanding mode.