battery grid feedback

[minerva]

Does anybody know if the popular Growatt and MPP "hybrid" inverters (or others) that have grid feedback have the ability to do BATTERY grid feedback?

Updates:
According to MPP solar, only their MPI series has the battery-to-grid export feature. That's only 220V single phase so it doesn't work for me but FYI.
Sol-ark and Deye based inverters seem to be able to do that. Unfortunately, Deye doesn't make split-phase inverters anymore and Sol-ark is $6,000.
Schneider is also capable of battery export, at least some models. $3,000+
Growatt likely does NOT carry this feature but I have not been able to confirm that for sure.

 

[fafrd]

Does anybody know if the popular Growatt and MPPT "hybrid" inverters (or others) that have grid feedback have the ability to do BATTERY grid feedback?

What do you mean by ‘grid feedback’ - do you mean export?

 

[minerva]

What do you mean by ‘grid feedback’ - do you mean export?

Yes, feed power back to the grid.

 

[OffGridInTheCity]

The basic categories of using PV input are off-grid (do not send power to the grid), grid-tie (only feed power to the grid), and hybrid (off-grid + send power to grid). Yes MPP Solar makes hybrid systems.

 

[minerva]

The basic categories of using PV input are off-grid (do not send power to the grid), grid-tie (only feed power to the grid), and hybrid (off-grid + send power to grid). Yes MPP Solar makes hybrid systems.

Yes. The question is can they send power to the grid from the battery, not the solar system. Apparently, not all, if any, do.

 

[OffGridInTheCity]

Yes. The question is can they send power to the grid from the battery, not the solar system. Apparently, not all, if any, do.

I wouldn't look at it this way. There's no advantage of sending power to the grid from your local battery!
The goal might be to charge your battery from the grid and then use that power in your home if the grid goes down... this can be either off-grid or hybrid. MPP Solar has different models that can do either of these cases. (Not pushing MPP - there are others but MPP off-grid is the one I have experience with).

 

[Smokin]

It's happening now

 

[OffGridInTheCity]

It's happening now

This won't work for DIY. Maybe if you buy Tesla equipment and sign away your rights - I certainly wouldn't

 

[minerva]

I wouldn't look at it this way. There's no advantage of sending power to the grid from your local battery!
The goal might be to charge your battery from the grid and then use that power in your home if the grid goes down... this can be either off-grid or hybrid. MPP Solar has different models that can do either of these cases. (Not pushing MPP - there are others but MPP off-grid is the one I have experience with).

The idea is not so much to send power to the grid, though my super-peak rate is something like 5-fold my night rate so one may even consider that.
What I need is to send battery power to the main loads via the AC-in port of the inverter. Hope that makes sense.

 

[OffGridInTheCity]

The idea is not so much to send power to the grid, though my super-peak rate is something like 5-fold my night rate so one may even consider that.
What I need is to send battery power to the main loads via the AC-in port of the inverter. Hope that makes sense.

It does and this is done by off-grid or hybrid systems. In off-grid, when the battery is charged enough you convert DC -> AC and I share it thru my home via ATS (automatic transfer switches).

MPP Solar all-in-one off-grid is roughly like this....
1) Take in Grid AC + Optional Solar Panel DC
2) Charge the battery if it needs it
3) Outputs AC
-----
4) If you add an ATS you can direct the #3 AC output automatically to your home circuits but you cannot send excess power back to power company.

Hybrid
1) Takes in Grid AC + Optional Solar Panel power
2) Charge the battery if it needs it
3) Sends the AC into you're home wiring and any excess back to the power company lines (outside your house). This is the grid-tie portion of hybrid.
**Requires approval from your power company and they may dictate equipment choices**


Grid-Tie Inverter w/Limiter - stand-alone unit like this - https://www.amazon.com/Marsrock-Inverter-Limiter-Voltage-Turbine/dp/B07QGRFS73/ref=sr_1_2
1) You do you're own battery
2) You charge your battery yourself - maybe grid powered battery charger
3) Hook this to home wiring... BUT it has a sensor that stops excess from going out the power company
**If power escapes to the grid and you hurt someone outside your home its not good but several DIY'ers go this route**

There are many different systems. Some might even let you choose between all 3 above thru settings but cost bigger $.
But the basics are Off-grid, Grid-tie, and Hybrid

This can be a very complicated topic for your personal expectations and I'm not trying to convince you of any particular solution - but trying to share the right 'buckets' of info to help you learn. I hope others will comment... and extend the discussion or present info in a different way to help you on your journey

 

[fafrd]

The idea is not so much to send power to the grid, though my super-peak rate is something like 5-fold my night rate so one may even consider that.
What I need is to send battery power to the main loads via the AC-in port of the inverter. Hope that makes sense.

If your primary goal is time-shifting, you might want to have a look at the GTIL inverters (Grid Tie Inverter Limited).

They allow you to charge a battery during the day from solar then discharge it to cover some or all consumption during peak hours.

It is not legal to send power to the grid without an agreement with your utility.

It is legal to reduce your grid consumption (through whichever manner you see fit).

The major advantage of GTILs is that they are connected fully in parallel with the grid and this has two important applications:

1/ no rewiring required (just a new two-phase breaker in the mains panel for GTIL connections).

2/ can be sized for average rather than peak load levels (whenever there is load demand exceeding GTIL maximum output power, y TA he additional needed power is just drawn from the grid).

 

[GXMnow]

I do not have any experience with GroWatt or MPP inverters, but I can say for sure that the Schneider XW-Pro will sell to grid from the battery. There are not many that will because of the grid code requirements. When the grid is up, I have mine set to push 900 watts back out the grid input side. This allows it to help power the loads that are in my main panel. You can tell it how many amps to push back and time limit it. I only have it push to my main panel during the peak rate which is about triple my off peak rate. When I am running my air central conditioner, pushing that power to the main panel can save me close to $3.00 a day. It drops to about $1.50 to $2.00 on days with less load in my main panel, as I try not to export to the grid from battery, but it will do it without a problem. I may end up adding a "WattNode" which measures the power on the grid input to my home, and it can auto adjust the output of the XW-Pro to meet the demands in the main panel while limiting the export that goes out to the grid.

This is not a cheap system by any means. The XW-Pro inverter runs about $3,000 for a 6,800 watt low frequency inverter. But it is fully UL rated and meets the grid codes for legal use just about anywhere. The WattNode box that I need to true grid zero export control is about $500 more with the current transformers. The budget GTIL inverters may sort of do the job, but the ones I looked at did not meet the code requirements and did not have safety lab testing listing. When you are talking about pushing a couple thousand watts around your home, be careful what you connect. Time shifting the power to peak time will not pay for the inverter and batteries, but being able to time shift the power is helping to pay for having backup power when the grid goes down.

 

[fafrd]

It does and this is done by off-grid or hybrid systems. In off-grid, when the battery is charged enough you convert DC -> AC and I share it thru my home via ATS (automatic transfer switches).

MPP Solar all-in-one off-grid is roughly like this....
1) Take in Grid AC + Optional Solar Panel DC
2) Charge the battery if it needs it
3) Outputs AC
-----
4) If you add an ATS you can direct the #3 AC output automatically to your home circuits but you cannot send excess power back to power company.

Hybrid
1) Takes in Grid AC + Optional Solar Panel power
2) Charge the battery if it needs it
3) Sends the AC into you're home wiring and any excess back to the power company lines (outside your house). This is the grid-tie portion of hybrid.
**Requires approval from your power company and they may dictate equipment choices**


Grid-Tie Inverter w/Limiter - stand-alone unit like this - https://www.amazon.com/Marsrock-Inverter-Limiter-Voltage-Turbine/dp/B07QGRFS73/ref=sr_1_2
1) You do you're own battery
2) You charge your battery yourself - maybe grid powered battery charger
3) Hook this to home wiring... BUT it has a sensor that stops excess from going out the power company
**If power escapes to the grid and you hurt someone outside your home its not good but several DIY'ers go this route**

There are many different systems. Some might even let you choose between all 3 above thru settings but cost bigger $.
But the basics are Off-grid, Grid-tie, and Hybrid

This can be a very complicated topic for your personal expectations and I'm not trying to convince you of any particular solution - but trying to share the right 'buckets' of info to help you learn. I hope others will comment... and extend the discussion or present info in a different way to help you on your journey

Good explanation / summary, but GTILs are not Hybrid Inverters (or conventional grid-tie) and deserve their own 4th class.

Hybrid inverters require being wired in the power path between grid and Critical Loads. GTIL inverters do not. This means:

-Lowest-possible rewiring cost (none).

-No need to size inverter for peak loads - sizing for average loads accomplishes most of what you want.

-No new ‘box’ in the critical power path - if the GTIL inverter fails, things continue to run as usual off of grid power.

-No grid-backup capability - while a true Hybrid Inverter can power critical loads off of battery power when the grid goes down, GTIL inverters require the grid signal to function and turn off when the grid goes down.

 

[minerva]

It does and this is done by off-grid or hybrid systems. In off-grid, when the battery is charged enough you convert DC -> AC and I share it thru my home via ATS (automatic transfer switches).

MPP Solar all-in-one off-grid is roughly like this....
1) Take in Grid AC + Optional Solar Panel DC
2) Charge the battery if it needs it
3) Outputs AC
-----
4) If you add an ATS you can direct the #3 AC output automatically to your home circuits but you cannot send excess power back to power company.

Hybrid
1) Takes in Grid AC + Optional Solar Panel power
2) Charge the battery if it needs it
3) Sends the AC into you're home wiring and any excess back to the power company lines (outside your house). This is the grid-tie portion of hybrid.
**Requires approval from your power company and they may dictate equipment choices**


Grid-Tie Inverter w/Limiter - stand-alone unit like this - https://www.amazon.com/Marsrock-Inverter-Limiter-Voltage-Turbine/dp/B07QGRFS73/ref=sr_1_2
1) You do you're own battery
2) You charge your battery yourself - maybe grid powered battery charger
3) Hook this to home wiring... BUT it has a sensor that stops excess from going out the power company
**If power escapes to the grid and you hurt someone outside your home its not good but several DIY'ers go this route**

There are many different systems. Some might even let you choose between all 3 above thru settings but cost bigger $.
But the basics are Off-grid, Grid-tie, and Hybrid

This can be a very complicated topic for your personal expectations and I'm not trying to convince you of any particular solution - but trying to share the right 'buckets' of info to help you learn. I hope others will comment... and extend the discussion.

I appreciate it. See, here is the thing. The off-grid example doesn't apply. The inverter has only one AC port. Sure the battery can power that port; that it's its main function.
The hybrid example does apply but the question remains. A hybrid inverter has an AC-in and an AC-out port. AC-in can charge the battery and export unused solar power out to the grid. The AC-out port powers the critical loads and sure can use the battery. Now, the issue is it's not guaranteed that the battery can power the AC-in port (the same way solar can). For example, you want to power non-critical loads (connected to the grid and therefore the AC-in port) during peak hours. Above and beyond the critical loads.

 

[minerva]

I do not have any experience with GroWatt or MPP inverters, but I can say for sure that the Schneider XW-Pro will sell to grid from the battery. There are not many that will because of the grid code requirements. When the grid is up, I have mine set to push 900 watts back out the grid input side. This allows it to help power the loads that are in my main panel. You can tell it how many amps to push back and time limit it. I only have it push to my main panel during the peak rate which is about triple my off peak rate. When I am running my air central conditioner, pushing that power to the main panel can save me close to $3.00 a day. It drops to about $1.50 to $2.00 on days with less load in my main panel, as I try not to export to the grid from battery, but it will do it without a problem. I may end up adding a "WattNode" which measures the power on the grid input to my home, and it can auto adjust the output of the XW-Pro to meet the demands in the main panel while limiting the export that goes out to the grid.

This is not a cheap system by any means. The XW-Pro inverter runs about $3,000 for a 6,800 watt low frequency inverter. But it is fully UL rated and meets the grid codes for legal use just about anywhere. The WattNode box that I need to true grid zero export control is about $500 more with the current transformers. The budget GTIL inverters may sort of do the job, but the ones I looked at did not meet the code requirements and did not have safety lab testing listing. When you are talking about pushing a couple thousand watts around your home, be careful what you connect. Time shifting the power to peak time will not pay for the inverter and batteries, but being able to time shift the power is helping to pay for having backup power when the grid goes down.

Bingo. IS there an inverter that does that but doesn't cost an arm and a leg?

 

[fafrd]

I do not have any experience with GroWatt or MPP inverters, but I can say for sure that the Schneider XW-Pro will sell to grid from the battery. There are not many that will because of the grid code requirements. When the grid is up, I have mine set to push 900 watts back out the grid input side. This allows it to help power the loads that are in my main panel. You can tell it how many amps to push back and time limit it. I only have it push to my main panel during the peak rate which is about triple my off peak rate. When I am running my air central conditioner, pushing that power to the main panel can save me close to $3.00 a day. It drops to about $1.50 to $2.00 on days with less load in my main panel, as I try not to export to the grid from battery, but it will do it without a problem. I may end up adding a "WattNode" which measures the power on the grid input to my home, and it can auto adjust the output of the XW-Pro to meet the demands in the main panel while limiting the export that goes out to the grid.

This is not a cheap system by any means. The XW-Pro inverter runs about $3,000 for a 6,800 watt low frequency inverter. But it is fully UL rated and meets the grid codes for legal use just about anywhere. The WattNode box that I need to true grid zero export control is about $500 more with the current transformers.

The budget GTIL inverters may sort of do the job, but the ones I looked at did not meet the code requirements and did not have safety lab testing listing. When you are talking about pushing a couple thousand watts around your home, be careful what you connect. Time shifting the power to peak time will not pay for the inverter and batteries, but being able to time shift the power is helping to pay for having backup power when the grid goes down.

This is absolutely correct.

It’ll be interesting to see whether the ‘Powers That Be’ ever authorize GTILs for use here in the US.

Until then, the best way to think about them is like one of the all-in-one solar generators like the Jackery that you are using to power some of your appliances such as your fridges.

Not exactly the same thing but the GTIL inverters plug into a standard 120V outlet just like a Toaster Oven…

 

[minerva]

Good explanation / summary, but GTILs are not Hybrid Inverters (or conventional grid-tie) and deserve their own 4th class.

Hybrid inverters require being wired in the power path between grid and Critical Loads. GTIL inverters do not. This means:

-Lowest-possible rewiring cost (none).

-No need to size inverter for peak loads - sizing for average loads accomplishes most of what you want.

-No new ‘box’ in the critical power path - if the GTIL inverter fails, things continue to run as usual off of grid power.

-No grid-backup capability - while a true Hybrid Inverter can power critical loads off of battery power when the grid goes down, GTIL inverters require the grid signal to function and turn off when the grid goes down.

I actually don't care about the limiter part, exporting to the grid is OK. Those, if appropriately used, should not impose a threat to anybody as the inverter shuts down if the grid is down. The one linked above however doesn't seem to have a battery option.

 

[fafrd]

Bingo. IS there an inverter that does that but doesn't cost an arm and a leg?

Define ‘arm and a leg’

 

[minerva]

If your primary goal is time-shifting, you might want to have a look at the GTIL inverters (Grid Tie Inverter Limited).

They allow you to charge a battery during the day from solar then discharge it to cover some or all consumption during peak hours.

It is not legal to send power to the grid without an agreement with your utility.

It is legal to reduce your grid consumption (through whichever manner you see fit).

The major advantage of GTILs is that they are connected fully in parallel with the grid and this has two important applications:

1/ no rewiring required (just a new two-phase breaker in the mains panel for GTIL connections).

2/ can be sized for average rather than peak load levels (whenever there is load demand exceeding GTIL maximum output power, y TA he additional needed power is just drawn from the grid).

Can you think of a model? I have an agreement to export so the limiter part is not even very relevant.

 

[minerva]

Define ‘arm and a leg’

Something in the range of Growatt would be acceotable.