grid tie inverter

[David99]

I found a lot of inverters that can be connected to a battery but are not grid tied.
I also found a lot of inverters that are grid tied but fed by solar panels.
I'm looking for an inverter that is fed by a battery but also connects to the grid.

Any suggestions are appreciated.

 

[miimura]

Outback Power makes inverters that are very flexible for battery and grid. They call them hybrid inverters.

 

[MichaelS]

I have a Schneider XW 6042 in my solar system that runs from 48V battery and is grid tied. I can also switch it off the grid and run the full house off the battery. It's been running perfectly for over four years.

 

[idoco]

Sunny Island. Will act as AC-->DC battery charger from grid. Will act as DC-->AC inverter from batteries. Connect two together and you can have 240V.

Also can work with solar inverters, wind inverters and generators. When grid goes down it has a built in transfer switch to isolate your house from the gird.

 

[gavine]

Go on eBay and search. You'll likely find many choices.

 

[nwdiver]

I found a lot of inverters that can be connected to a battery but are not grid tied.
I also found a lot of inverters that are grid tied but fed by solar panels.
I'm looking for an inverter that is fed by a battery but also connects to the grid.

Any suggestions are appreciated.

Which of the following most closes matches your objective;

1) Going Off-Grid Completely
2) Using the grid only as back up
3) Peak Load shedding and load shifting
4) Emergency backup for the whole house
5) Emergency backup for critical loads

 

[Ampster]

As mentioned above, Outback Radian series hybrid inverters can do it all. Also see the thread by Jason who used several Radians:
Plan: Off grid solar with a Model S battery pack at the heart

 

[nwdiver]

As mentioned above, Outback Radian series hybrid inverters can do it all. Also see the thread by Jason who used several Radians:
Plan: Off grid solar with a Model S battery pack at the heart

Yes, but they don't do it very well... A Radian system is ~90% efficient and ~$0.60/w VS a grid-tied system at $0.20/w and 97%. Radian systems are not cost effective unless you're trying to be ~100% off-grid.

For power generation >4kW you really want voltage >200v. Radians operate at 48v. I have a 8kW grid-tie. If I wanted to generate 8kW with a Radian I'd need wire that could handle ~170A instead of ~24A.

 

[miimura]

Yes, but they don't do it very well... A Radian system is ~90% efficient and ~$0.60/w VS a grid-tied system at $0.20/w and 97%. Radian systems are not cost effective unless you're trying to be ~100% off-grid.

For power generation >4kW you really want voltage >200v. Radians operate at 48v. I have a 8kW grid-tie. If I wanted to generate 8kW with a Radian I'd need wire that could handle ~170A instead of ~24A.

Sure, but who makes an inverter system as feature complete as a Radian with a HVDC battery input? I can only think of Pika Energy and they don't have an open system for batteries - you have to use their complete battery system. They also don't have all the same system-level features.

 

[David99]

Which of the following most closes matches your objective;

1) Going Off-Grid Completely
2) Using the grid only as back up
3) Peak Load shedding and load shifting
4) Emergency backup for the whole house
5) Emergency backup for critical loads

Main and actually only purpose is to reduce peak time usage. It's a battery that is charged over night and discharged during the day. Yes kind of what the powerwall does, but I already have a battery so I only want an inverter that is grid tied but is not using solar panels as a source. All grid tied inverters I found are optimized for solar input.

 

[nwdiver]

Yes kind of what the powerwall does, but I already have a battery so I only want an inverter that is grid tied but is not using solar panels as a source. All grid tied inverters I found are optimized for solar input.

What kind of battery do you have? The Radian would work but a PowerWall would probably be cheaper in the long run....

 

[David99]

What kind of battery do you have? The Radian would work but a PowerWall would probably be cheaper in the long run....

My car is the battery

 

[nwdiver]

My car is the battery

??? Are you trying to tap into 12v or ~350v? 'cause the radian won't work with either....

 

[David99]

??? Are you trying to tap into 12v or ~350v? 'cause the radian won't work with either....

12 Volt. The main battery is too dangerous.

 

[nwdiver]

12 Volt. The main battery is too dangerous.

The amount to load shedding you'll be able to do via the 12v is probably a rounding error

I don't know how powerful the DC-DC converter is but I'd bet it's <500w. If you want to do load shedding buying a PowerWall is probably your best bet....

You can do Demand Response with your car... for now that's probably even better....

 

[miimura]

Outback does make a grid tie inverter for 12VDC and 120VAC, 2,800W max (VFXR2812A). You could leave it connected to DC in the Frunk and limit it to 12A @ 120VAC and plug it into a normal outlet in your garage. However, you would need some kind of control system to vary its output to zero out your usage at the utility meter to get the most out of it. The Tesla DC-DC is supposedly 2,500W, so if you leave it in "camper mode" it will work.

Given all that, I just don't see that it's a worthwhile project. I would have a lot more respect for an emergency power system connected like this. In that case, you could use a much cheaper inverter that doesn't sync to grid.

 

[nwdiver]

The Tesla DC-DC is supposedly 2,500W, so if you leave it in "camper mode" it will work.

That's 200A... I seriously doubt that...

The cabin heater, battery heater and compressor tap off the DC-DC converter but I don't think they're 12v.

 

[miimura]

That's 200A... I seriously doubt that...

The cabin heater, battery heater and compressor tap off the DC-DC converter but I don't think they're 12v.

ALL EVs are at least 125A on the 12V side of the DC-DC, so 200A is believable. The figure came from Jack Rickard, so you can choose to believe or not based on his reputation and experience.
Those other high drain devices you mentioned all run on HVDC. The DC-DC is a high voltage junction box of sorts too.

 

[nwdiver]

ALL EVs are at least 125A on the 12V side of the DC-DC, so 200A is believable.

What's the source for that? The best I can find is this thread that mentions a 15A limit for the 12v outlet and ~100A limit for the DC-DC converter to 12v...

 

[miimura]

What's the source for that? The best I can find is this thread that mentions a 15A limit for the 12v outlet and ~100A limit for the DC-DC converter to 12v...

The second post in that thread corroborates the 2,500W DC-DC rating.