Thanks for the detailed response.Outback Radian GS4048 or 8048.. Outback might be a slightly better quality than the Victron but that could be argued.
SMA Sunny Islands are the best on the market, hands down by far, but also more expensive.
Magnum inverters are a quality alternative
Victron makes good inverters, and they have great software.
I use Samlex, the UL458 version. They top out at about 3000 watts.
Imo, the ul458 for mobile use or whatever the equivalent is for the fixed grids tied use would be a min baseline.
Depending on your country, I’m sure Theresa standard.
Those people went to Midnite. So it goes Trace->Outback->MidniteOutback has most of the original experienced Trace designers.
I'm new to this too but, as I understand it, there are inverter-charger-controller systems that are not grid-tie but do use the grid for some battery charging etc. If the grid gos down the batteries and solar take over without energizing the grid.Right now my solar setup is off grid only. Just for backup power.
are there options if I want to go on grid and be able to switch to battery backup if the power goes out? I’m based in texas.
I'm new to this too but, as I understand it, there are inverter-charger-controller systems that are not grid-tie but do use the grid for some battery charging etc. If the grid gos down the batteries and solar take over without energizing the grid.
If you install a normal grid tied solar system, you can then install an battery inverter capable of AC Coupling which can use that grid tied solar system while off-grid.
My solar system does exactly this. We have 11kW of grid tied solar using two SMA Sunny Boy grid inverters.. These inverters are subject to UL1741 which means they will shut down if they don't detect proper grid voltage parameters.
But there's a plot twist with our setup..
We also have a battery backup system.. A battery bank powers a pair of SMA Sunny Island inverters.. When the grid goes down, we turn on the off-grid system which causes the grid tied system to think the grid is still active and it starts to make power again. While the process is supposed to be wired to be automatic, we keep our off-grid system totally isolated at all times unless its being used.
The off-grid system connects to our home's breaker panel through a generator interlock breaker that can't be turned on unless the main breaker is turned off. This assures our off-grid system can never pump energy into the grid and hurt any of the powr company folks.
The technique we use is called AC Coupling. The Sunny Islands make such clean power that the Sunny Boy grid inverters think the grid is working again.
If the solar array makes more power than the house is using, the extra juice is used to charge the batteries.. if it doesn't make enough, then the Sunny Island battery inverters make up for the deficit by drawing energy from the batteries and adding it to the energy the solar array is making.
Very few battery inverters are capable of AC Coupling. I know that the SMA Sunny Islands can do it, and I know the Outback Radian inverters can do it, but I'm not sure about any of the Victron systems or even Schnieder.. You'd have to check on those...
As for the grid inverters, any grid inverter is capable of AC Coupling, but some of them are capable of an extra feature called Frequency Shift Power Control. My SMA Sunny Boy inverters are capable of the FSPC.. this feature is used to "throttle" the output power of the normally grid tied solar inverters so that when the battery is fully charged and the array is making more power than needed, the battery inverter (in my case Sunny Islands) can throttle the array to exactly match the needs of the house. No energy goes into or out of the battery system, thus prolonging the life of the battery.
Here's a pic of my off grid system. It is not hooked up in this picture because its not in use.
We just lost power this past weekend.. big storms knocked out almost a million people in Michigan.. System worked flawlessly and we lived as if the grid was still working.
Yup, the full 11kW of solar pushing power through two 6kW SMA Sunny Boy inverters is fully available.. but we don't use it, we normally shut one inverter off unless its cloudy or winter time when the sun is at a low angle.I’m sold. This is the exact setup I’m looking for. Now I need to do a whole lot of research. Much obliged.
edit
so your panels still make power, even when the grid is down (after you disconnect from the grid)?
Perfect. I will start with one sunny boy and one sunny island and build up from there.Yup, the full 11kW of solar pushing power through two 6kW SMA Sunny Boy inverters is fully available.. but we don't use it, we normally shut one inverter off unless its cloudy or winter time when the sun is at a low angle.
11kW of solar pushing 55 volts into a battery bank works out to 200 amps of charge.. LOL.. I set my maximum charge rate to 100 amps.
If we run the air conditioner WHILE charging the battery, then I will turn on the 2nd inverter and use full capabilities of the warp drive, otherwise, I usually don't need both inverters running off grid..
It works so well, I sometimes forget we're off grid.. Lucky for me, my neighbor just installed one of those automatic Generac whole house generators and so now I have a reminder.... when his generator stops running, I know the grid is back up.
The Sunny Island inverters are 120 volts only.. You either need a transformer to turn the 120 into 240 (which works fine), or you need a second Sunny Island inverter, which not only gives you 240, but doubles your power from 6kw to 12kw..Perfect. I will start with one sunny boy and one sunny island and build up from there.
Im new to the grid connected thing. Does the sma grid tie require micro inverters? Where do you buy them?
My panels are around 40v each. 400v won’t be a problem. I already have the permit from the city.The Sunny Island inverters are 120 volts only.. You either need a transformer to turn the 120 into 240 (which works fine), or you need a second Sunny Island inverter, which not only gives you 240, but doubles your power from 6kw to 12kw..
As for the Sunny BOY grid tied inverters, you will probably need to reconfigure your panels. Most off grid solar arrays operate in the 100 volt range, but with grid tied systems, you string your panels together until you're up in the 300 to 450 volt range.
Yes, start by getting the proper city permits for a grid tied solar array.. install it and get it working.. Your local power company will have to reprogram your utility meter so it registers reverse current flow.
Once that's up and running, you can dig into using a battery inverter to make an AC Coupled off grid system.
Solar panel inverters come in two configurations.. String inverters and Micro Inverters.Perfect. I will start with one sunny boy and one sunny island and build up from there.
Im new to the grid connected thing. Does the sma grid tie require micro inverters? Where do you buy them?
My goal is to move out of the city and get at least an acre or so. I’m debating how much of this I will do at the current home.Solar panel inverters come in two configurations.. String inverters and Micro Inverters.
String inverters means you attach a "string" of solar panels.. Eight 40 volt panels connected in series makes 400 volts to the string inverter.
Micro inverters are individual little boxes that attach to each solar panel. You need one micro inverter for each panel. I don't like them myself.. they have pro's and con's, but for me, I like string inverters.
Ground mount systems are generally better than roof mounted panels.. easier maintenance, better cooling.
There's nothing wrong with string inverters, I just don't like them for personal reasons..My goal is to move out of the city and get at least an acre or so. I’m debating how much of this I will do at the current home.
I have a few victron controllers I’m using now. I’m not sure why I thought all grid tied inverters had to have micro inverters. I also prefer string inverters.
Hey Hedges,I also use Sunny Island + Sunny Boy. This works well both grid-tie net metering and backup when grid goes down. Good surge current to start motors.
SMA also offers Sunny Boy Storage, a 400V battery high-frequency inverter (like Sunny Boy but with batteries added.) It requires an expensive lithium battery. This allows peak shaving. With an add-on transformer & relay it also provides backup. Fairly wimpy surge current.
MSRP of Sunny Boy Storage + Automatic Backup is similar to MSRP of one Sunny Island. But you can pick up new liquidation Sunny Islands about 50% off, so same dollars gets you two of them.
Some brands/models of micro inverters do AC coupling (they support frequency-watts).
But I like string inverters. No performance loss if some panels in a single string are shaded (except for the shaded ones themselves.) If multiple strings in parallel on a single MPPT input, then some shading conditions cause loss greater than just the shaded panels. String inverters used to have a large cost advantage, but that may be reduced/eliminated if "Rapid Shutdown" box per PV panel is required (new code for rooftop.) If ground mounts, then not needed.
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