Can I have 2 grid tie inverters in one house?

[Lmc1342]

Hi,

Currently have 1 grid tie inverter in my house.
Looking to add another inverter + panels in my garage.
The garage runs off the same grid connection.

Can I connect 2 grid tie inverters to the one mains incoming?
And if so can someone explain how it works ie the power generated from inverter2, would it just sample it out at a higher voltage to inverter 1 to overcome inverter 1, and then inverter 1 samples higher than grid.

Thanks

 

[zanydroid]

Hi,

Currently have 1 grid tie inverter in my house.
Looking to add another inverter + panels in my garage.
The garage runs off the same grid connection.

Can I connect 2 grid tie inverters to the one mains incoming?
And if so can someone explain how it works ie the power generated from inverter2, would it just sample it out at a higher voltage to inverter 1 to overcome inverter 1, and then inverter 1 samples higher than grid.

Thanks

You can, this is basically how microinverters work… plenty of people have 20-30 on their roofs.

As to how the voltages sort themselves out. Not fully sure. The GTI are most likely not going to be able to move the voltage much, it would just be the voltage drop from the current being pushed to the utility transformer. This should still be within the ride-through voltage operating range of the inverter.

The voltage at the place in circuit where both inverters meet will always be the same voltage, by KVL. The inverters will independently “raise their voltage” (or do other tweaks to their PSW PWM output) to achieve the target output power. That is a function of the voltage drop to the combiner point (separate wires) and then from combiner point to utility. Probably solvable with Ohms law.

 

[DIYrich]

"grid-tied" is the key word here. "off-grid" and "grid down" needs some way to moderate the two (control production). Enphase as AC PV input into the Gen Port of the Sol-Ark would have the Sol-Ark controlling production.

 

[SeaGal]

Can I connect 2 grid tie inverters to the one mains incoming?
And if so can someone explain how it works ie the power generated from inverter2, would it just sample it out at a higher voltage to inverter 1 to overcome inverter 1, and then inverter 1 samples higher than grid.

Thanks

Yep, and pretty much as you described. It's technically same config as you and your neighbour having an inverter. The issue will be getting your G99 approval and comms between inverters if your DNO limits your export power.