Sunny Island w/ Grid Tie?

[schmoot]

I recently purchased a battery pack ~1000AH of 48V FLA batteries and a Sunny Island inverter/charger at a bankruptcy auction. I was assuming that I could use this setup similarly to how powerwalls are used, where I could charge it during the day when I have excess solar generation or the grid is at a lower rate, and discharge it during peak pricing/night time. However, I cannot find any documentation that describes how to set this up, just for pure off grid operation or pure battery backup (grid is down).

Does anyone know how to setup the Sunny Islands to operate in a load shifting scenario? Or is this not possible with this equipment?

[NEOH]

This article states Sunny Home Manager can control the Sunny Island to shift "Time-Of-Use" costs with a battery ...

https://files.sma.de/dl/7680/SmartHome_Time-of-use-TI-en-11.pdf

[schmoot]

[Edited to make it clearer]

Thanks for sharing that document! That does make it sound like it can be used to load shift, not just schedule charging times.

All of the installation documentation that I can find for the Sunny Island show an install with the battery being discharged during grid outages only. Is there any different installation instructions available that show how to install it to support load shifting as mentioned in that document?

Does anyone have any experience with the sunny islands? I jumped on the inverter and batteries due to the really good price, but unfortunately are not as educated as I'd like to be on these setups. Up until I saw these, I was in the process of going with a 2 powerwall install with tesla. The price of this setup is much cheaper, but I understand will require more work and maintenance. I also am in the process of having a solar edge inverter installed with solar, wondering if that is compatable w/ charging while the grid is down or not.

Thanks for bearing with me as I learn!

[NEOH]

You say, that you can only "... install with battery being discharged during grid outages ONLY ..." <= HUH?
I have never seen that restriction, in the Sunny Island manual.
You "can" configure the battery to discharge, ONLY when the grid is down <<< But that is an option, it is not a requirement.
The documentation clearly states that the battery can be discharged when the Grid is ACTIVE.

See battery behavior 2.4.a below...

2.4 Battery Behavior outside of the Battery Charging Window Outside of the battery charging window, the battery behaves in accordance with its normal function:
a) If power is drawn at the grid-connection point, the battery inverter attempts to compensate for the purchased electricity by discharging the battery. <<< See this ?
b) If excess PV power is being fed in at the grid-connection point, the battery inverter attempts to balance the grid feed-in by charging the battery.
c) If the maximum charging power of the battery storage system is exceeded in this mode, electricity is fed into the utility grid.
d) If the maximum discharge power of the battery storage system is exceeded in this mode, electricity is drawn from the utility grid.

Take a look at these two parameters in the 231# General Menu ...

#1) 231.01 PvFeedTmStr = Start time for PV grid feedin in hh:mm:ss
#2) 231.02 PvFeedTmStp = Stop time for PV grid feedin in hh:mm:ss

I believe, these two Sunny Island parameters determine when to START Exporting AC Power into the Grid and when to STOP exporting
Configure for your "Peak Rate" Period.

The Grid Status parameter should be set to "Feed (6)" = Grid operation with Grid feed-in enabled.
The Grid Mode parameter should be display "Allow Grid Feed-In", not as "Grid Charge only"

[schmoot]

Thanks for pointing that out.

Do you happen to have a link to the manuals/docs that you are going off of? They copy of the 6048-US manual I have does not have much information about battery discharging while connected to the grid (https://www.altestore.com/static/dat..._Manual_V2.pdf).

The manual does have the settings for Feed and pvFeedTmStr and PvFeedTmStp but doesn't explain how to configure them to discharge battery based on usage.

IThe only statement that I can find:

"Utility grid as generator: connecting the utility grid as soon as the loads request high power from the Sunny Island

You can configure the Sunny Island in such a way that it automatically connects to the utility grid once the connected loads request high power from the Sunny Island. To activate this function, set the parameter "232.42 GdPwrEna" to "Enable". The Sunny Island connects to the utility grid when the power requested by the loads is within the limits determined by the following parameters:

• "233.07 GdPwrStr" to "233.08 GdPwrStp"

[Info] Grid feed-in into the utility grid

If the parameter "232.08 GdMod" is set to "GridFeed", the Sunny Island can feed into the utility grid, regardless of whether parameter "232.42 GdPwrEna" is enabled or disabled."

Or perhaps all the information is there, and I'm just having problems finding it .

Thanks again!

[schmoot]

Had a discussion with SMA engineering department. They claim there is no official way to use Sunny Island to do load shifting based on Tarrifs, and that functionality is only available on sunny boy storage. They said that the Sunny Island will only back feed the grid with excess energy that is produced by the PV system that cannot be used to charge batteries. It will not allow discharging of batteries back into the grid.

They did say however, that I could use the multi-function relays on the sunny island to control a transfer switch to move have the critical load panel disconnect from the grid and run off of the batteries. The multi-function relays can be programed based on SOC or time of day.

This is counter to what was discussed here, so would love some more details on an installation that allowed discharging from the batteries w/o the needs for the transfer switches.

[schmoot]

Followed up with another conversaation with SMA and received additional clarifications. The Sunny Island can support his scenario with the European versions, it is not supported by the US version.

So, the question is why is it not support in the US version, and is the functionality actually blocked, or just not official supported but will work with the correct settings.

[Markyrocks69]

Had a discussion with SMA engineering department. They claim there is no official way to use Sunny Island to do load shifting based on Tarrifs, and that functionality is only available on sunny boy storage. They said that the Sunny Island will only back feed the grid with excess energy that is produced by the PV system that cannot be used to charge batteries. It will not allow discharging of batteries back into the grid.

In what scenario would backfeeding battery charge into the grid be a reasonable option? Pretty sure in areas where power walls are popular you're not usually allowed to back feed or charge the batteries from the grid. The reasoning for this is if you're backfeeding from batteries when rates are high and charging from the grid when rates are low you're basically gaming the system. The point of these battery backup systems is for self consumption not milking the most money out of the poco.

[Markyrocks69]

Followed up with another conversaation with SMA and received additional clarifications. The Sunny Island can support his scenario with the European versions, it is not supported by the US version.

So, the question is why is it not support in the US version, and is the functionality actually blocked, or just not official supported but will work with the correct settings.

Its not supported bc its probably against the rules in most jurisdictions.

Also whatever financial benefits you think that you'll be gaining by this are more than likely to evaporate when the lifespan of the batteries are severely diminished and youll be forced to buy another set of batteries or completely change your system. I'd put money on the batteries you bought at auction being already on their way out.

[schmoot]

Sorry, I don't actually mean to discharge power back onto the grid, but rather discharge batteries to supply loads while still on the grid. Meaning power loads from battery during high cost periods.

I am aware that this will reduce the life cycle of the batteries, but given 1500 cycles at 50% DOD they should last 5 years even if I did this every day. My peak to off peak price difference is 40 cents per KWh, and peak times have shifted to evening so solar won't capture it.

Even with the reduced battery life, this is well worth it for me, I can save $1000 - $1500 a year, more than making up for the price of the battery at $2400. And in regards to the battery life from auction, it's definitely a risk, but the battery pack was new, still on pallet wrapped in plastic and delivered to the company within the past 9 months, so hopefully in good shape.


I can do the transfer switch solution, but it unfortunately would only power my critical load panel, which won't include my heat pumps, which is the biggest user of peak rate power.

[Markyrocks69]

Sorry, I don't actually mean to discharge power back onto the grid, but rather discharge batteries to supply loads while still on the grid. Meaning power loads from battery during high cost periods.

I am aware that this will reduce the life cycle of the batteries, but given 1500 cycles at 50% DOD they should last 5 years even if I did this every day. My peak to off peak price difference is 40 cents per KWh, and peak times have shifted to evening so solar won't capture it.

Even with the reduced battery life, this is well worth it for me, I can save $1000 - $1500 a year, more than making up for the price of the battery at $2400. And in regards to the battery life from auction, it's definitely a risk, but the battery pack was new, still on pallet wrapped in plastic and delivered to the company within the past 9 months, so hopefully in good shape.


I can do the transfer switch solution, but it unfortunately would only power my critical load panel, which won't include my heat pumps, which is the biggest user of peak rate power.

I get what you're saying.

Ok so it looks like page 158 has the parameter lists. I'm looking at the manual .

Honestly I think that your best option option just selling off that sunny island and buying a inverter that has the capabilities that you're looking for.

[schmoot]

I agree. It's weird that the tech support / application engineering team is saying it's not supported in the US. I also noticed that it allows to adjust the maximum input current, I wonder if limiting that to 1A will force the Sunny Island to discharge battery to service loads, if programatically accessible that would be easier than installing a auto transfer switch that is controlled by relay.

[Salts]

I recently purchased a battery pack ~1000AH of 48V FLA batteries and a Sunny Island inverter/charger at a bankruptcy auction. I was assuming that I could use this setup similarly to how powerwalls are used, where I could charge it during the day when I have excess solar generation or the grid is at a lower rate, and discharge it during peak pricing/night time. However, I cannot find any documentation that describes how to set this up, just for pure off grid operation or pure battery backup (grid is down).

Does anyone know how to setup the Sunny Islands to operate in a load shifting scenario? Or is this not possible with this equipment?

Why not just MAKE the grid go down yourself? Put a relay/contactor on your grid lines and hook that to the Multifunction relay inside the Sunny Island. From there, you would use the TMR1 or TMR2 setting (there are two multifunction relays in each Sunny Island) to disconnect the Grid for a specific amount of time. By activating one of the relays, it would trigger a contactor to disconnect the grid on a daily routine.

My Sunny Islands are 6048's.. not sure which one you have.

[littleharbor]

I think the reason the US version isn't compatible is that it is a 120 single phase only output. I may have missed it but I thought the Sunny Islands needed to be coupled with a similar sized Sunny Boy grid tie inverter to be able to work with the grid.
You may want to get those FLA batteries on a charger right away and see if they are not sulfated. They may need remedial action.

[Salts]

I think the reason the US version isn't compatible is that it is a 120 single phase only output. I may have missed it but I thought the Sunny Islands needed to be coupled with a similar sized Sunny Boy grid tie inverter to be able to work with the grid.
You may want to get those FLA batteries on a charger right away and see if they are not sulfated. They may need remedial action.

I don't think they do. I have a Sunny Island 6048 and I see no reason it would require a solar system or any other power generation device. So long as it has charged batteries, it will produce power.
If it required solar input, how would it produce power at night? The Sunny Island 6048 can charge the batteries using multiple power sources. Either then grid or a generator on the AC2 terminals, or solar/wind/hydro on the AC1 terminals. The AC1 terminals are connected to the loads.. AC1 is an output but can function as an input so long as the power sources connected to the AC1 can be throttled via frequency control. The AC2 terminals are input only so far as I can tell.. which is strange because the AC2 is a bidirectional inverter.. why have a bidirectional inverter on an input only terminal?

If he connects the grid to the AC2 terminal and hooks up the battery, all he needs is a few menu setup items and the Sunny Island will charge the batteries.