Help needed to understand micro-invertors, or single large Grid-Tied invertors.

[warlock]

Hi Guys,

What the difference between the micro invertor setup and the string array invertors.

I understand that the string type like the victron's accept high DC current and do the conversion to AC, where the micro invertors
do it at a per panel.

How though are the micro-invertors controlled to disconnect from the grid if the utility is down.
From a cost perspective which is the better option ?

[SeanB]

Micro inverters make for a simple modular unit that is easy to add to later if you want to build a system as finances allow, as the panel and inverter are sized on a per unit basis. With the regular method you are basically buying a block of panel and inverter, and if you want to expand it later you will basically have to buy it again.

As to grid tie, both use the same method of disconnecting on overload and as well disconnecting on rising mains frequency in the normal anti islanding method. One just has a single mains tie at the inverter, the other has the mains fed to all the panels where each inverter then does it's own share of adding power. Micro inverters do have the advantage of failing gradually, if a unit is faulty it just reduces output by the panel amount, not by not working at all.

[warlock]

Thanks Sean,

A question regarding grid-tie in, with the single unit and string array, if the mains from the utility is down does the unit disconnect the feed back to the utility until the mains has returned but still provide electricity to the house?
And how about the micro-invertors ?

So what I am asking do either or both systems still supply you with electricity "during the day" if the mains are down ?

From what I gather each micro invertor is connected directly to your mains and so should the mains go offline then so will your house ? but I am unsure of weather the larger single Grid-Tie invertors do the same ?