[EU] Powerwall and 3-phase 400VAC

[miimura]

Again, I could live with 1-phase power backup, just need to know it works.

If you want to be able to survive an extended power outage, you should find out what your 3-phase solar inverters will do when only one phase is alive. If it shuts down completely, you won't be able to charge the Powerwalls when the grid is down. Best case, you will still generate on one phase, up to the capacity of that one line (nominially 1/3 of the inverter AC power).

Also, you should ask about the 3-phase metering. If you want to be "Self Powered" and charge the Powerwall(s) from the solar and discharge from the Powerwalls at night, you need to be sure that the metering is net of all three phases because the power flows could be significantly different on the three phases at any given time. For example, during the mid-day your solar could be generating 9kW spread across all three phases but the Powerwall could be charging with 5kW on only the L1 phase. The flows on L2 and L3 would be 3kW negative and the Powerwalls plus critical loads could be 9kW positive. The net flow is zero but it is very imbalanced. Maybe the utility doesn't care. I don't know, but I'm pretty sure that is what will happen in a 3-phase Gateway 2 installation. If you have a 63A per phase service, you also won't be able to install more than 2 Powerwalls because this imbalance situation would overload one phase if you had more than that.

 

[EvilMonkey]

I live in New Zealand and are having a very similar issue.

My house will be three phase but there will be no appliances etc that use three phase. The house will be split into three sections and run off individual phases.

This is fine except when you get unbalance loads across the phases. It means if I am producing 6kw Solar and one phase wants 2kw and the other two want 1kw it will send 2kw to each phase. On the two that only require 1kw it will send the excess to the grid which is not very cost effective or to my battery.

If I am not producing enough it will draw the extra 2kw from the grid. I am not sure what happens to that, perhaps it can be stored on the battery.

If I install a telsa powerwall 2 it can only be across one of the phases so there could be some inefficiency when the above scenarios happen.

The solution one company has come up with for me is using the solax 10kw 3phase inverter that supports unbalanced loads. It only support unbalanced loads when it has two batteries connected to it. This company has proposed 2x 4.6 KW solax batteries that support 3 phase.

So in this scenario I would have a system that support unbalanced loads, so more efficient for my 3 phase setup and the battery is across all three phases. It has an EPS built in but requires etc wiring and generally just supports one circuit in case of a power cut. Or you can go the cheap solution and just do one powerpoint.

This unfortunately is really my only option, even though I wanted the power wall 2. The price point is very similar and I can add a 3rd battery which would bring me upto the same capacity as the powerwall 2 for a very similar cost.

 

[lorn10]

Okay Folks,

There exist since April of this year from Fronius and BYD an officially approved three-phase AC, high-voltage DC package. This quite interesting single-inverter solution includes also backup and basic off grid functionality. The BYD battery is based on lithium iron phosphate LiFePO4 and outperforms any lithium cobalt phosphate LiCoO2 variant.

Yes, it is more heavy than a Tesla Powerwall 2 or a LG RESU 13 but that's not a real drawback because a house battery hasn't to be moved (like a car).

- 1x Fronius Symo Hybrid 5.0-3-S => three-phase AC
- 1x BYD Battery-Box HV 11.5 => expandable up to 57,6 kWh

this will give:
- 11.5 kWh capacity
- 11,52 kW max. output performance of the battery (Note, that will be limited because of the inverter!)
- 23,04 kW max. peak für 5 min

A Sunny Island concept would have most likely better off-grid and backup functionality. However, it is 48V low-voltage DC based and need's more expensive solar cabling and three inverters. So for private use, this three-phase Fronius solution may be the way to go.

 

[miimura]

Okay Folks,

There exist since April of this year from Fronius and BYD an officially approved three-phase AC, high-voltage DC package. This quite interesting single-inverter solution includes also backup and basic off grid functionality. The BYD battery is based on lithium iron phosphate LiFePO4 and outperforms any lithium cobalt phosphate LiCoO2 variant.

Yes, it is more heavy than a Tesla Powerwall 2 or a LG RESU 13 but that's not a real drawback because a house battery hasn't to be moved (like a car).

- 1x Fronius Symo Hybrid 5.0-3-S => three-phase AC
- 1x BYD Battery-Box HV 11.5 => expandable up to 57,6 kWh

this will give:
- 11.5 kWh capacity
- 11,52 kW max. output performance of the battery (Note, that will be limited because of the inverter!)
- 23,04 kW max. peak für 5 min

A Sunny Island concept would have most likely better off-grid and backup functionality. However, it is 48V low-voltage DC based and need's more expensive solar cabling and three inverters. So for private use, this three-phase Fronius solution may be the way to go.

That looks like a nice system for 3-phase. The question is, what is the cost of a system roughly comparable to 2 Powerwalls? That would mean at least 2 11.5kWh battery boxes with the one 3-phase inverter. This is actually the problem with most systems that are trying to compete with the Powerwall - some cost as much as the Powerwall before you even include the battery cells.

The Sunny Island system is very good. AC coupling has its advantages, especially in a more distributed micro-grid situation. They should release a version of the Sunny Island that uses HVDC 300-600VDC. A version with native 3-phase would also be attractive, but only necessary for smaller installations where you need less than 18kW (3pc 6kW each)

 

[fresnoboy]

Inverter Supply has the BYD 2.56Kwh battery module for sale at $1701, and the base (that supports up to 4 modules) for $747. It's getting close to the Powerwall 2 in economics, but is DC coupled for much more flexibility. They say it works with SMA inverters on the website, but I am guessing most of the DC coupled inverter folks will try and make this work.

One thing you know about BYD, they will push prices down aggressively.

I would prefer to do the Tesla Powerwall approach, but Tesla's gateway and lack of real generator support is pretty constraining. It'll be nice to have a more flexible alternative that just works with lots of different hybrid inverter configurations.

 

[lorn10]

That looks like a nice system for 3-phase. The question is, what is the cost of a system roughly comparable to 2 Powerwalls? ...

In Europe, the prices excluding VAT in € are approximately:

- €2200 for the Fronius Symo Hybrid 5.0-3-S hybrid inverter
- €5600 for the BYD B-Box H 11.5 kWh solar battery

So this will give a total of around €13400 for two batteries and the inverter.

The interesting on this Fronius - BYD solution is not only the DC coupled battery. Also the PV is DC coupled, - and this feature makes that combination at the moment quite special. That topology should get a real good overall efficiency.

 

[lorn10]

I live in New Zealand and are having a very similar issue. ...

Here follows a short addition, - the Fronius / BYD package is now officially announced (and supported) also for Australia:
BYD Battery-Box HV

I know, New Zealand is not Australia but these two are somewhat nearer than Europe.

Alternatively it seems to be possible to buy the Fronius Symo Hybrid inverter and the BYD HV DC battery (in New Zealand) separately. So you have to config it yourself. This should work because the BYD HV battery-support should be now (as of September 2019) enabled in all newer Fronius Symo Hybrid firmware releases. However, - this may be true only for the European firmware builds.

No information is at the moment available regarding the US market. Fronius may or may not introduce that package in America. (The most English information regarding the Fronius Symo Hybrid belongs to the UK and Australia.)

 

[miimura]

Here follows a short addition, - the Fronius / BYD package is now officially announced (and supported) also for Australia:
BYD Battery-Box HV

I know, New Zealand is not Australia but these two are somewhat nearer than Europe.

Alternatively it seems to be possible to buy the Fronius Symo Hybrid inverter and the BYD HV DC battery (in New Zealand) separately. So you have to config it yourself. This should work because the BYD HV battery-support should be now (as of September 2019) enabled in all newer Fronius Symo Hybrid firmware releases. However, - this may be true only for the European firmware builds.

No information is at the moment available regarding the US market. Fronius may or may not introduce that package in America. (The most English information regarding the Fronius Symo Hybrid belongs to the UK and Australia.)

Don't worry about America. Residential is completely covered by the existing Tesla Powerwall solution for whole home backup. We don't use 3-phase in residential at all. That may be why Tesla is deficient in 3-phase solutions.

 

[nativewolf]

Here follows a short addition, - the Fronius / BYD package is now officially announced (and supported) also for Australia:
BYD Battery-Box HV

I know, New Zealand is not Australia but these two are somewhat nearer than Europe.

Alternatively it seems to be possible to buy the Fronius Symo Hybrid inverter and the BYD HV DC battery (in New Zealand) separately. So you have to config it yourself. This should work because the BYD HV battery-support should be now (as of September 2019) enabled in all newer Fronius Symo Hybrid firmware releases. However, - this may be true only for the European firmware builds.

No information is at the moment available regarding the US market. Fronius may or may not introduce that package in America. (The most English information regarding the Fronius Symo Hybrid belongs to the UK and Australia.)

As an American small farm owner (only a few of us left ) I'd love to have 3phase, much of our wood workshop equipment is 3 phase, etc. It would really open up options but ..then there is the question of how much load can it support, how long, etc.

 

[Jays200]

Here follows a short addition, - the Fronius / BYD package is now officially announced (and supported) also for Australia:
BYD Battery-Box HV

I know, New Zealand is not Australia but these two are somewhat nearer than Europe.

Alternatively it seems to be possible to buy the Fronius Symo Hybrid inverter and the BYD HV DC battery (in New Zealand) separately. So you have to config it yourself. This should work because the BYD HV battery-support should be now (as of September 2019) enabled in all newer Fronius Symo Hybrid firmware releases. However, - this may be true only for the European firmware builds.

No information is at the moment available regarding the US market. Fronius may or may not introduce that package in America. (The most English information regarding the Fronius Symo Hybrid belongs to the UK and Australia.)

And here's my 5n 6.4kWh BYD waiting for my 3phase Fronius Symo Hybrid install this Friday. My second 5kW inverter.

 

[Jays200]

And an updated pic

And yesterday's generation

 

[miimura]

I like how the SOC is shown on the chart. I wish Tesla would do that. 6.4kWh sure goes fast though. I think the Powerwall 13.5kWh is a good amount of storage and that capacity would likely help @Jays200 make it through the night with self-consumption.

 

[Jays200]

I like how the SOC is shown on the chart. I wish Tesla would do that. 6.4kWh sure goes fast though. I think the Powerwall 13.5kWh is a good amount of storage and that capacity would likely help @Jays200 make it through the night with self-consumption.

I didn't want to add a battery but my utility made me add it because I wanted to go above the max PV allocation of 8.2kW for a 3 phase connection. Unfortunately, the PW2 in Australia is only a single phase solution. My hope is PW3 will be 3 phase and that will be my next addition.

My utility has an EV tariff which gives me a 30% discount from 11p-4a so that helps get me through 'till the Sun shines again.

 

[lorn10]

Here follows again a little addition to that topic.

The Kostal PLENTICORE plus inverters seems to be also a really nice DC-coupled, 3-phase AC solution. They are since a while also compatible withe the BYD HV batteries. These inverters are avaiable up to 10 kW (!) and include 3 MPP tracker. For comparison, the Fronius Symo Hybrid inverter are avaiable only up to 5 kW and includes just 1 MPP tracker. More information can be found in the attachment and the following link (it's in German):

https://www.solarmarkt.ch/artimg/20-Wechselrichter/Kostal/DB_DE_Kostal_Plenticore.pdf

Interestingly, the underlying architecture seems a quite solid one. The Kostal PLENTICORE plus uses like the very similar Stecagrid 10013 film capacitors. They are clearly more robust then electrolytic capacitors. For example, Fronius uses at their solar (hybrid) inverters the later one. I have found that information at the following discussion here (it's in German):

KOSTAL PLENTICORE plus - Photovoltaikforum

However, the most interesting aspect for me (in Central Europe) is that there exist no power limitation at the AC side. As I mentioned already, the Powerwall 2 is redistricted in Switzerland to ridiculous 3.6 kW AC (one phase).

The Kostal PLENTICORE plus 10 can deliver up to 10 kW AC (three phase).

So far I can see, the only drawback at the Kostal PLENTICORE plus inverter line is the missing backup / off-grid functionality. The Fronius Symo Hybrid has it, like the SMA Sunny Island inverters.

 

[lorn10]

It's time for a new little update regarding this 3-phase topic.

Fronius has announced recently their new Symo Gen 24 Plus 3-phase inverter line which seems to be the new efficiency champion. It outperforms the previously mentioned (also quite efficient) Kostal PLENTICORE plus inverters. According to the latest HTW Energy Storage Inspection 2020 the Fronius Symo Gen 24 Plus 10.0 reaches a middle inverter efficiency of 97,3%.

Source:
https://pvspeicher.htw-berlin.de/wp-content/uploads/Energy-Storage-Inspection-2020.pdf

Or more detailed from the German PV Magazine:
HTW Stromspeicher-Inspektion 2020: Systeme von Fronius, RCT Power und Kostal überzeugen mit hoher Effizienz

The Fronius Symo Gen 24 Plus inverters are available up to 10 kW. The overall parameters are similar to the Kostal PLENTICORE plus inverter models. One big benefit is that the Symo Gen 24 Plus models comes with full 3-phase backup capability. The market availability (in Europe) is scheduled for June / July 2020.

More information can be found a the Fronius website:
Fronius Symo GEN24 Plus 10.0

Well, the time is running, and it seems that Tesla falls behind more and more. The new Fronius Symo Gen 24 Plus inverters lines leaves nearly no wish unfulfilled, - at least for the power range of 10 kW .

 

[miimura]

Interesting. It requires a battery pack voltage of 474VDC or higher to reach it maximum battery output of 10.4kW at 22A. Battery pack voltage must be between 160VDC and 700VDC.

 

[Jays200]

Yes, the GEN24 seems very impressive and will be my next inverter with a BYD battery, however, I still want a Tesla Powerwall 3 3 phase at the front of my setup so all the other inverters never see the grid go down because the Powerwall mimics the grid instantly.

 

[tsllst]

@widodh

Do you have the tesla powerwall installed now?

3-phase solar is very common in EU (Netherlands in my case). Anything above ~5kW solar needs to be connected to three phase.

The house I'm building right now will get 11kWp of solar and thus will be connected 3-phase.

I could live with just backup on one phase so I can run my:

- Fridge
- Ventilation system
- Critical lights
- WiFi router and access points
- CCTV system

Other things which won't work:

- AC/Heat pump
- Warm water
- Car chargers

The idea is indeed to balance phases.

Not all appliances are three phase, but once they become big they'll be three phase. My AC/Heatpump for example can draw up to 10kW 400V 3-phase. Same goes for both our Model S which can draw 17 ~ 22kW from 3-phase 400V.

The voltage between L-N is 230V and L-L is 400V.

Other appliances like ovens and boilers are usually 2 ~ 3kW, but you spread them over the phases to keep them balanced.

Again, I could live with 1-phase power backup, just need to know it works.

 

[widodh]

@widodh

Do you have the tesla powerwall installed now?

No. I do live in my new house and have 11kWp of PV with a SolarEdge SE10k inverter on my roof.

The powerwall with 3-phase is still very unknown and thus I just went with PV. I'll cycle back to this in a few years when this has matured more.

 

[lorn10]

Well, the point is that there exist now with the Fronius Symo Gen 24 Plus and Kostal PLENTICORE plus two very good 3-phase hybrid inverters. As already mentioned, these two are super efficient and outperform most other models. For more information check the above link to the "Energy-Storage Inspection 2020" comparison.

So for me it's a no-brainer. If you really want a powerful 10kw 3-phase solution, get one of them (@tsllst). While the PLENTICORE plus has some nice features in regard to a multiple-inverter config (currently not fully implemented), the Symo Gen 24 Plus offers a solid 3-phase backup capability.

And regarding the battery technology, - it may be for some hard to accept, but the modular LiFePo4 (lithium iron phosphate) technology is the future in the "fixed place" (non-mobile) sector. According most technical parameters like peak consumption it outperforms Teslas LiCoO2 (lithium cobalt oxide) cells which are used in the Powerwall.

The only disadvantage of the lithium iron phosphate technology is the weight. However, in a "fixed place" application like a house battery this point isn't really important. It can be solved with a modular concept. BYD shows with his "Battery-Box Premium" models how this can be archived.