# Inverter advice



## Meinecke (Jun 30, 2017)

Hello out there...
I was already a while just reading here and got already a few good tips, but now i have a question that i cant get answered that generalized.
I got my hands on 20x175 Watt Panels
Conergy S 174MU to be precise.
Now i am looking for a grid tie inverter, but that is all so overwhelming, that i got lost...
Combined these panels do max 3500 Watt and 600 Volt is the Panel voltage maximum...
So i guess i have to do 2 branches a 440 Volt to stay below that limit...or what would you say?
What kind of inverter would you take for this setup?
And as extra info...it is a hobby budget, so please no Mercedes class suggestions if possible
Thx in advance


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## Murby (May 24, 2016)

While it might be tempting to go with a cheap Chinese hobby inverter, I wouldn't waste my money. Instead, I'd go with a small SMA inverter. Buy it once and be done with it.

For about $1188, you can get an SMA Sunny Boy SB 3.0 US.. Good for 3000 watts of power which is what you're system will put out. 
You could get the SB 3.8 US for another few bucks ($1234). 

The SMA inverters will also provide you with up to 2000 watts of power in a grid-down situation.. Something not many other inverters will give you.

Be careful doing this.. If you tie into your grid, you probably need to be permitted by your utility provider and they'll need to replace your meter with a bidirectional unit. 
If you attempt to feed power back to the grid without a bidirectional meter, you could be paying not only for the power you use, bu the power you pump back. Most normal household utility meters don't know and don't care with way the current is flowing, they just add it up for your bill.. So if your grid tie system is pumping 1 KWh into the grid, your meter might think that's how much power your home is using.


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## Meinecke (Jun 30, 2017)

Hello and thx for your reply...
I tried to read through the specs and think it is pretty pleasing...
But 600V max DC input might be a problem, right?
Or does this one have 2 strings with EACH 600V max?
Thx for some details...


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## Murby (May 24, 2016)

Meinecke said:


> Hello and thx for your reply...
> I tried to read through the specs and think it is pretty pleasing...
> But 600V max DC input might be a problem, right?
> Or does this one have 2 strings with EACH 600V max?
> Thx for some details...


It has three MPPT inputs.. each input can take up to 10 amps @600 volts. It would be wise to split your array into three electrical paths. So if you have 20 panels, you could go 7 + 7 + 6 in any configuration you wish.. You could go 10 + 10 and leave the third input for future expansion.. 

SMA also has a web browser enabled ethernet which lets you log on and see the power your panels are producing and it stores 30 years (I think) worth of data..


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## Meinecke (Jun 30, 2017)

Looked at that one...it looks it has only two inputs...but they still would work fine in the 10x10 version...
I will check the market...thx for the advice...


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## Murby (May 24, 2016)

They have a bunch of SMA inverters on ebay too.. 
http://www.ebay.com/itm/NEW-SMA-Sun...546310&hash=item2f06672178:g:Sn0AAOSww5hZGMfF
Some good deals but you might want to check the warranty..


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## Al Yaz (Jun 13, 2017)

I know almost nothing about grid tie set ups. So you are talking no battery bank for back up, just a straight grid tie?


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## Meinecke (Jun 30, 2017)

Starting slow...Got my 20 panels for only GAS costs...so i thought starting with single axle tracker ground mount first and work my way up to dual axle tracker and later on moving towards more energy efficiency at home and when battery budget allows it towards Off grid or Grid assisted...


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## Al Yaz (Jun 13, 2017)

Nice! If you are in no rush I am sure you can search out parts and pieces as you did the panels. Heck I gave /bartered away a C30 charge controller a few years ago. Starting slow also helps to avoid expensive errors


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