One, two or three grid tied inverters? Help please!

[briggsy]

I have an existing  1.1 kw PV system with Sunny Boy 1.2kw inverter. I've also just purchased a 2nd hand (almost new) 1.9 kw PV system with 2 kw Chinese inverter plus I'm installing a 2kw wind turbine for which I have yet to purchase an inverter(thinking Aurora 3.6) Would there be grid connect issues with having three different brands of inverters all feeding into the meter? This would be my cheapest option. I have 2 phase supply coming into meter.   

I've been told this may cause problems. One suggested option was to replace my two existing inverters with a 3.6 Aurora (dual inputs for two sets of panels) then buy another 3.6 solely for the wind turbine.

Another option is to buy one inverter to handle everything but I'm concerned about too many eggs (or panels)  in the one basket if something goes wrong.

Any help (or experience with above)  would be appreciated

[dnix71]

Unless the inverters were made to be stackable, then I don't think you will get permission to do it.

If you can afford all this equipment then you might consider one big inverter for the solar, and then ask your electric supplier how much it would cost to add a meter just for the mill.

If something goes wrong with one system you still have the other, plus solar and wind are hard to combine like that unless everything goes into batteries and then gets inverted and backfed from there.

The pv system puts out steady dc. A mill doesn't. The voltages won't match either. That's why it difficult to combine the two.

[DamonHD]

I have 4 separate grid-tie inverters for PV in my loft.

They should be synchronising to the mains, not to one another.

If they even notice one another then you need thicker cabling back to your consumer unit.

Rgds

Damon

[Jon Miller]

The SunnyBoy and the Aurora inveters are both Galvanicly isolated inverters so should be ok to plug into the mains together.  Not sure what chinese inverter you have but they made need to be checked.

Just to clear up, each power source will need their own seperate inverters, ie PV needs a PV inverter and the wind turbine needs a wind turbine inverter.

I would suggest that you check to see if your original PV arrray and your new PV array are compatable with an SMA 4000TL inverter as this has two MPPT inputs strings, so you will only need one inverter without one string pulling down the other string.  Sell the SunnyBoy 1200 and use it to buy the Aurora or a WindyBoy.

Regards

Jonathan

[fabricator]

It's likely that unless the chinese inverters are UL approved you won't allowed to grid tie them anyway.