Which 2022 hybrid solar inverters can do export from battery to grid?

[400bird]

Sweden. All power companies except the island of Gotland is required to accept solar installations. Energy meters installed can already measure power in both directions.

Nice! (for everyone except island residents)

The Schneider XW pro 6848 did mention both dumb lithium, lead acid and two-stage charging curve so seems very DIY friendly. I did not however find whether it could export from battery to grid, and 6.8 kW is small so I would need two. Pros and cons of splitting the battery pack in half for each.

You wouldn't split the pack. Two can be run in parallel off the same pack. I believe they support up to 4 running networked together.

How do you do when you sell from battery to grid with yours? Can you set it via Ethernet, WiFi, RS-232 or similar?

It has a web portal with about 1 bazillion settings if you can do time based sell to grid, but it sounds like you'd need to change the schedule almost daily.

I control it via Modbus over TCP/IP (ethernet) with a raspberry pi. Another member here controls his via a small industrial PLC.

 

[Shimmy]

How do you run the XW-Pro 6848 three-phase? Doesn't it require three inverters?

The duck curve is a result of high solar penetration (and few batteries). Sweden isn't there yet, and I imagine seasonal effects are much more dramatic than diurnal effects on the load side.

 

[400bird]

How do you run the XW-Pro 6848 three-phase? Doesn't it require three inverters?

Yikes, I'm pretty sure it does. That gets expensive real quick when you have to buy in multiples of 3!

I missed the 3 phase requirement.

Also, the 6848 is built for split phase.
Schneider makes a similar single phase unit the 8548 that is probably more applicable to use in Sweden.
OP would need to do some research, but by the name/number it may have different output ratings

 

[Hedges]

In U.S., I think Sunny Boy Storage does that (battery inverter, coupled to their PV inverters.
US model Sunny Island does not backfeed grid from battery, at least not unless different target voltages get stuffed into it on the fly.

European model Sunny Island may do that.

For 3-phase, look at SMA's new hybrid offering:

Hybrid-Wechselrichter Sunny Tripower Smart Energy | SMA Solar

Entdecken Sie mit dem Sunny Tripower Smart Energy Hybrid-Wechselrichter von SMA die kompakte 2-in-1-Lösung zur Solarstromversorgung im Eigenheim.

www.sma.de

 

[winny]

In U.S., I think Sunny Boy Storage does that (battery inverter, coupled to their PV inverters.
US model Sunny Island does not backfeed grid from battery, at least not unless different target voltages get stuffed into it on the fly.

European model Sunny Island may do that.

For 3-phase, look at SMA's new hybrid offering:

Hybrid-Wechselrichter Sunny Tripower Smart Energy | SMA Solar

Entdecken Sie mit dem Sunny Tripower Smart Energy Hybrid-Wechselrichter von SMA die kompakte 2-in-1-Lösung zur Solarstromversorgung im Eigenheim.

www.sma.de

Thanks. Uses 600 V battery which would complicate things a lot on the battery side but as an EE, I understand why from the manufacturers point of view.

 

[Hedges]

We haven't heard of DIY batteries in the 400V +/- range. For 48V battery, REC makes a BMS compatible with Sunny Island. Don't know which BMS might work for SBS or TriPower Smart Energy.
REC BMS can be configured up to 128S, so covers the voltage range.
I would think a uP could be configured as protocol converter between any BMS and any inverter.

Of course for commercial/industrial scale inverters which SMA also sells (75kW to 4MW), battery would be high voltage. For the consumer market with 3kWh to 10kWh or so, the batteries are 48V (or maybe a small multiple of that?) with bidirectional boost converter. Which certainly limits the output current at full voltage, although may not into a dead short unless it is an isolated converter.

I'm interested in the possibility of Sunny Boy Storage and high voltage series connected lithium battery, for use with the 48V battery inverter Sunny Island. My system has AGM 48V battery, which simplifies some things, but ideally would be kept at float by recharging from lithium. Not a supported configuration.

I may do similar for my truck with 12V AGM. Power a 12V inverter, but keep charged from 48V lithium which in turn is charged by PV. (Partly for historical reasons, what equipment I have on hand.) In this case, I'm planning to use Midnight Classic as 48V to 12V charger.

 

[winny]

After months is search, the only suitable candidate I've found is the Deye SUN-10K-SG04LP3-EU.

Except for the fixed scheduling, the only way I've found to automate it is via MODbus commands. Deye took months to respond to my email but understood what I wanted to do and did send me the MODbus specifications. Mandarin original and machine translated versions are attached if anyone else need them.

Useful search terms for future reference: SUN-5K-SG04LP3-EU, SUN-6K-SG04LP3-EU, SUN-8K-SG04LP3-EU, SUN-10K-SG04LP3-EU, SUN-12K-SG04LP3-EU.

I'll update my post once I have bought it and implemented communication to it in Arduino.

 

[bullfrog84]

After months is search, the only suitable candidate I've found is the Deye SUN-10K-SG04LP3-EU.

Except for the fixed scheduling, the only way I've found to automate it is via MODbus commands. Deye took months to respond to my email but understood what I wanted to do and did send me the MODbus specifications. Mandarin original and machine translated versions are attached if anyone else need them.

Useful search terms for future reference: SUN-5K-SG04LP3-EU, SUN-6K-SG04LP3-EU, SUN-8K-SG04LP3-EU, SUN-10K-SG04LP3-EU, SUN-12K-SG04LP3-EU.

I'll update my post once I have bought it and implemented communication to it in Arduino.

I'm looking into something similar, except I wasn't planning to buy at nighttime and sell during daytime. My idea was to simply charge from the panels and sell the exces during peak hours (but yours is an even more devious idea I have to admit ).

Out of interest... did you manage to progress with your project?

 

[zanydroid]

You should probably check your interconnect agreement to see if those configs are legit. This is definitely regulated where I am (California), but I know in other areas it's OK.

 

[DIYrich]

I'm looking into something similar, except I wasn't planning to buy at nighttime and sell during daytime. My idea was to simply charge from the panels and sell the exces during peak hours (but yours is an even more devious idea I have to admit ).

Out of interest... did you manage to progress with your project?

Might want to look into whether you can use Solar Assistant to control an inverter remotely. It might open up more options.