Net Metering: Why you can add a Sunny Boy Storage to a single or 3-phase PV system

by Daniel Chung (guest post), , 22 Comments

With the Sunny Boy Storage range of battery inverters, you can add battery storage to either a single phase or a three-phase PV system. Households in Australia are billed for their energy using net metering across all three phases of the grid. That means, the net energy purchased across all three-phases is what is billed, and it does not matter how energy is distributed across the phases.

Single Phase PV System and Sunny Boy Storage

In the animation below, the net power is always 0 kW no matter which phase the inverter is installed on or which phase the household loads are on. The Sunny Boy Storage can be installed on any of the available phases.

Three Phase PV system and Sunny Boy Storage

Similarly, the Sunny Boy Storage can be installed on any of the three phases at a site where there is a three-phase PV system. In the animation below, the home-owner is instantaneously billed 0 kW whether energy is supplied from the PV system or the Battery system.

Conclusions

The Sunny Boy Storage range is compatible with new or existing PV systems whether they are single or 3-phase. PV systems with non-SMA inverters may be accommodated.

Net metering ensures the single-phase Sunny Boy Storage can function on three-phase PV systems/sites. Note that for residential, grid-connected sites, there is no additional benefit of a three-phase battery inverter and is therefore an unnecessary cost add-on.

Check out the 2-minute video below:

How does net metering work for 3-phase sites?

 

22 Comments
  1. Les
    Les says:

    Net metering will mean there is no disadvantage in having the battery connected to a single phase in a 3 phase system, however what about battery back-up in a blackout? Can the Sunny Boy Storage be configured across all 3 phases for blackout protection?

    Reply
    • Christiane Keim
      Christiane Keim says:

      Hello Les,

      the Sunny Boy Storage is not able to form a true 3-phase backup grid.
      However, you can still use the backup feature to supply one of the phases which includes the most vital loads like the refrigerator and lights.
      In certain regions, SMA may provide solutions for phase coupling during backup operation.
      Please contact your local SMA Service in case you need further support.

      Sunny regards
      Christiane

      Reply
    • Almantas
      Almantas says:

      Hi Les, I am using Sunny Island 6.0H system that provides 14kW (4.6kW per phase) of uninterrupted supply to the home during blackouts. You just need 3 pcs. for 3 phases. The transfer time to battery is as good as 20ms, my loads (smart home, security DVRs/cams, PCs, TVs, lights) do not notice when transfer to battery happens. I only notice that the street and houses around are dark, but not my house 🙂 You can also select 3×8.0H if you need 6kW per phase (18kW total). Up to 30 minutes the loads can be higher, 6kW and 8kW per phase for SI 6.0H and SI 8.0H respectively, and 11kW per one phase (33kW total) for up to 3 seconds (to start a motor, and they sustain initial load up to amazing 120A). Bigger villas, hotels, etc. can even use multicluster box, selecting the 36kW, 72kW and up to 216kW models, sized for the power they need. The system is very stable due to high overloads well tolerated, also I was positively surprised that proper (rotating) 3 phase supply continued in a long partial grid fault event when there was just one phase from the grid (lift 3 phase motor continued to run properly), also battery is charged if the blackout happens when Tripower inverter is generating at day, so in sunny periods the blackout can continue for days without noticed. I am not related to SMA and I recommend Sunny Island for modern homes full of electronics that do not tolerate interruptions, based on my own positive experience. 100% of electricity 24x7x365, now 3 years in operation, with log of many blackouts (grid is not stable where I live).

      Reply
  2. Sven Carl
    Sven Carl says:

    Hi. The billing system in Denmark is exactly the same as in Australia.
    I would need a true 3-phase sunny boy storage system as you can not predict the use of power in the 3 phases. According to law we must install everything in order to have an equal power consumption in all 3 phases, but it will vary during the 24 hours. My inverter is STP 8000-10.

    Reply
    • Christiane Keim
      Christiane Keim says:

      Hi Sven

      Your local SMA Service will be able to find a solution that satisfies your local grid requirements.
      For example, unbalanaced load limitation feature in the Sunny Boy Storage may be required by some grid operators.

      Best regards
      Christiane

      Reply
  3. Alfred
    Alfred says:

    Good afternoon all,
    I have already a few weeks a problem with the first system above, we have STP10.0 and a SBS6.0 and 2 towers of BYD 11.00 kW. Now it seems that the energy from the batteries is going back into the grid. I will include a part of the email I received from the client. The installation is located near Lisbon, Portugal. Maybe you have an idea why or what happening here? Thank you already for your reaction.
    ———————————————————————————————————–
    My dear Alfred

    I am sorry to be disturbing your rest on a Sunday, but the matter is serious.

    As you know from the beginning, we never understood the reason why the EDP metter gave very different results compared to those measured by the SMA system. At first we thought that the problem was the unidirectional EDP meter; we pay for a new counter but with the new bidirectional meter the problem remained.

    Consumptions measured by EDP are twice as high as those measured by SMA. EDP’s bills have not seen a significant decrease now with the solar system !……

    The solar system was very expensive, mainly due to the high cost of the batteries and charger .

    The conclusion of this new study points out that it is cheaper to use the system without batteries! …..

    As you can see from the table that I send you during 3 1/2 days, we disconnect the batteries and the SMA system meter reproduces the EDP meter, a fact that had never happened before.

    Today I reconnected the batteries and within 3 1/2 days I will send you a new record which, as I hope, will show different values between SMA / EDP meter.

    This appears to be a serious problem with the system for which a quick fix is needed before it becomes clear that the investment in batteries and chargers was a huge mistake.

    Please review the electrical connections, ask for SMA help, etc, etc, but please solve as soon as possible this intriguing mistery

    Reply
    • Christiane Keim
      Christiane Keim says:

      Hello Alfred,

      Please contact our regional SMA Service Partner FF SOLAR ENERGIAS RENOVAVEIS, based in Aljezur.

      Sunnz regards
      Christiane

      Reply
      • Alfred op den Brouw
        Alfred op den Brouw says:

        SMA ff Solar didn’t know this too, we just discover during the way that SMA is not informing well his installers. UP to today, SMA owners with a 3 phase inverter and a Sunny Boy Storage will all have to pay for there anergy when they use the batteries. SMA Iberica informed me different see email below from SMA Iberica :

        Respeito ás dúvidas que voce falou:
        Pode conectar duas baterias num SBS. Ele é um inversor de baterias “multistring”
        Pode ligar em qualquer uma das fases tal e como comentou, já que o medidor trifásico calcula e resta as fases. Exemplo se voce tiver: F1: 3 kW / F2: 0 kW / F3: -3 kW, o medidor vai medir 0 kW.

        Abs

        J.G.H | SMA Ibérica|

        But this is not correct it seems now, here an email from the client after all research the client did. See part email of my client:

        I already have two EDP invoice.
        They based the bills to the figures the meter show !…..
        Any compensation system- direct reading and billing by the meter.

        From the 28th until sunday we were away from home and you can see the values:
        Screenshot 2021-05-03 at 09.49.10.png

        SMA registration 0,94 Kw and EDP meter 67 Kw !…….

        Last Saturday I lunch with a senior official at EDP, (recently retired) and he assured me that meters do not do any automatic compensation and that EDP does not. That was possible in the old meters, but with the new meters generation everything that the system injects is counted as an injection, everything that the network supplies is counted as a supply and there is no compensation system inside the meter.

        EDP today called me from EDP’s self-consumption department (Viana do Castelo) – an engineer confirmed to me that: “the problem is known and that if customers carefully check their consumption they will see that the battery solution does not always work well!…. “- he asked me right away if our battery charger was three-phase …, then he clarified that the meters do not make any compensation.

        So, after almost 3 months of misunderstanding how the system works, we must conclude:
        1. The system does not work within expectations.
        2. The economic gain from batteries is marginal. There is no reason to invest more than € 14 000 in a system that only provides 1/3 of the expected savings
        3. The current configuration does not work with the national energy supply standards of EDP and this fact CANNOT BE UNKNOWN BY SMA.
        4- The investment in batteries that, when everything works well is hardly justified, in this case then it is totally unjustified.
        5. Soon I will definitely disconnect the batteries and use only the direct consumption of the panels.
        6- I hope that in 15 days SMA and you will find a solution that works with EDP standards

        Alfred I believe that I have given all the help to make this installation a success, I have been understanding of the problems, I have been fully available to provide records and I will continue to do that, and I know that there have been efforts on your part, but the most recent conclusions let me to impose a different pace.

        On June 2, I will be away from home for several months and by that date I intend to have this dossier closed. We don`t have more time to fix this issue.
        I believe that it took us more than 3 months and that it is time to make decisions.
        The problem is identified and the SMA PROPOSED SOLUTION DID NOT RESULT.
        A perfect solution must be found quickly – SMA must clarify the problem with EDP ( not you neither me ) and if it is not working properly , SMA must correct it quickly.
        If this does not happen, I will definitely give up a battery solution.
        I await your news

        And as the client wants to know what SMA for solutions it can give, and why we received the wrong information, if we knew this before we never had installed this system!!

        Looking forward to hearing from SMA what your respond will be.

      • Christiane Keim
        Christiane Keim says:

        Hello Alfred,

        The Sales and Service Experts from SMA Iberica will get back to you regarding further support in that matter.

        Best regards
        Christiane

  4. Almantas
    Almantas says:

    Hi, to everyone not in Germany, not in Australia and Denmark, and even in these countries, beware that if you not signed feed-in contracts with your grid operator and have ordinary electronic grid counter, many grid counter models are NOT designed for bidirectional and they will count the electricity irrespective of the current (energy flow) direction!!! This is the case I am finding when asked for help at many cost-burned customers who attempted to use Sunny Boy/Island battery systems+Tripower solar inverters without signing the feed-in contract and without replacing the meter to bidirectional meter, just using the grid as generator. Huge bills are received despite that feed-in is set to zero, and SMA Home Manager 2.0 counters showing zero grid usage. In my own first lesson, it was 1.6kWh at SMA HM 2.0 counter and over 3000kWh on grid counter for the on-grid system that was not consuming and not-exporting! Let me explain the reason for this by example: when 3 phase load, let’s say heat pump at 6kW (2kW per phase x3 phases), is on, and single phase on-grid battery system generates 6kW into phase L1, to get net zero, the end result will be +4kW on L1, -2kW on L2, and -2kW on L3. Standard not bidirectional electronic grid counter will count as if there is 8kW of the load (4+2+2), that is, your kWh number to pay for will increase by 8kWh per hour, even if SMA HM 2.0 will measure net zero for that hour. Therefore, if you will disconnect the on-grid battery system at all, the counter will add just 6kWh per hour. That is what the confused customer is observing in the comments above. That is the reason of getting even higher invoices from the grid after installing battery systems that are not designed or do not care to keep all 3 phase currents at zero at metering (grid connection) point.
    Then, even after you will install bidirectional counter (that is only possible, in many countries, if solar panels/inverter is installed and commissioned), the accounting (net metering) is completely separate for each phase. Local grid operator is specifically explaining, that if there is a generation into one phase, that is feed-in, and if there is a consumption on another phase(s) at same time, that is purchase. As the price difference will be about 50%, depending on country regulations or grid operator tariffs, to achieve real net zero in the net metering bill, twice more energy should be generated into grid on L1, than there is consumption from L2/L3, to stay at zero net cost. Phase balancing is very costly grid service, and unfortunately every morning and evening we use a lot of this grid service. SW/logic upgrades in the SMA products are required to avoid this cost.
    This is what is much, much wanted from SMA by customers in many countries:
    a) ability to setup “Per phase grid metering” for Sunny Portal, for all statistics (counters) to work/count correctly in a countries with per-phase metering, and show two numbers (one in red, another in green) when there is both consumption (on some phases), and generation (on another phases) at same time, account in the app accordingly (account more for “Purchased”, “Grid feed-in”, and less for “Direct consumption” accordingly)
    b) ability to setup “Cover loads in other phases before starting feed-in” parameter for Sunny Island when grid is on, specifically for off-grid setups with grid connected instead of generator, which is the only reasonable Sunny Island (SI) investment usage for modern smart-homes, to avoid black-outs and have transfer to battery duration at 20ms. The SI top efficiency is above 95%, so even with energy passed from one SI to another SI device, close to 90% of energy will be delivered to another phase, the 90% is much higher cost efficiency compared to 50% cost of grid based phase balancing,
    c) if technically possible, in “Per phase grid metering=ON” situations, while inverters are not operating at their full loads, up to Tripower inverter per phase max. power capabilities, they shall directly generate more into particular phases where there is more load, to minimize the cheap feed-in and costly purchase at the same time.
    d) one phase EV charging must not be triggered in homes with “Per phase grid metering=ON”.

    In general, the things shown in this article may be considered as a form of grid abuse, even in Germany or Australia where sum of 3 phases are net-counted, as the currents to balance between phases will travel via grid outside the home, so there will be losses (in lines to transformer), and that means other customers will pay for the phase balancing current losses – even if that seems to be for free from the grid side. Company so big, so responsible, so green and so grid friendly as SMA needs to be, shall do everything possible to balance the phase load before the grid connection/grid meter point, not behind it at someone else’s cost. No current outside home flows for free (without loss), even if the grid in Germany is too much positive in accounting terms, this turns back against consumers in the forms of various over-regulations (various extra limits and permissions that are not needed elsewhere, etc.), compared to other countries where you can do whatever you want – but you pay for everything what you use.
    SMA is a high quality brand, for me it sounds as “Solar Mercedes”, with “Best or Nothing” philosophy on products. I hope these needs above to cover phase based net-metering are being developed and will come in future product SW updates, as SMA products are not for Germany only, and the needs of the customers in the countries with per-phase net metering will be respected.
    My home:
    2xSMA Tripower 20000TL-30, panels both on the roof and on south walls of the home
    30kW feed-in permission, 80kW usage permission, phase based net metering
    3xSunny Island 6.0H, off-grid mode with grid connected as generator, one Tripower and all protected 24×7 loads are behind SI 6.0H (in the “always on island”)
    60kWh VRLA 48V battery string
    SMA 2x EV 22kW chargers, just ordered, on the way.
    I am SMA products enthusiast. Former electrician.

    Reply
    • Vladim
      Vladim says:

      Switch to Victron then.
      You can choose metering type: per phase or phase balanced. Victron ESS can read data from SMA PV inverter as well as manage SMA inverter by frequency shifting in off-grid mode.
      I was also fan of SMA for a along time, but unfortunately SMA not PV pioneer anymore.

      Reply
      • Christiane Keim
        Christiane Keim says:

        Hello Vladim,

        Sorry to hear that you are not satisfied with SMA anymore.
        We would be happy to welcome you back again.
        So please get in contact with us in case you would like to discuss your questions.

        Best regards
        Christiane

  5. Alfred
    Alfred says:

    Good afternoon Almantas,
    thank you for this article,it is exactly how it is here in Portugal. I try to get an answer for weeks now from SMA Germany, SMA Iberica, who told me that it would work in Portugal, see email below of SMA Iberica; Sorry it is in Portuguese, but based on his email we installed 22kw BYD batteries at a client and now it is not working, and NO, BUT REALLY NO RESPONSE from SMA!! This is sad, I am, same as you, a big fan from SMA and we sell only SMA products, but now when they make a mistake or send the wrong message into the world is not good. Maybe there are hundreds of home owners how pay a lot and they even don’t know about it. Hopefully SMA will bring a three-phase hybride system on the market, then this will be solved, but for now we have to install a Fronius system. And we stay with second hand STP & SBS

    Respeito ás dúvidas que voce falou:

    Pode conectar duas baterias num SBS. Ele é um inversor de baterias “multistring”
    Pode ligar em qualquer uma das fases tal e como comentou, já que o medidor trifásico calcula e resta as fases. Exemplo se voce tiver: F1: 3 kW / F2: 0 kW / F3: -3 kW, o medidor vai medir 0 kW.

    Abs

    Reply
    • Christiane Keim
      Christiane Keim says:

      Hello Alfred,

      We will get back to you asap.
      Please apologize the delay occurred.
      Thanks for your understanding.

      Best regards
      Christiane

      Reply
  6. Alfred
    Alfred says:

    Good afternoon Madam Keim,
    It is now going on for a long time, and not even one person of SMA is getting back, SMA Portugal, is doing his best, but even your support desk for Portugal has to wait for weeks. I am/was a big fan of SMA and his products, but you guys let me down so deep in the drain. We are not a big company, but I will find out how many installations and clients are affected by this, because even the Sales manager from Iberica in Barcelona, give me a kick in my balls to let me know that it is not his problem, see text/email below. Is this how you thread your smaller clients??
    See here your friendly Sales managers comment:

    “Sorry but I don’t do service and don’t have time for doing service. FF Solar is having problems solving your doubt and needing help from Service International in Germany. What I am doing is to push Service International for supporting you. Be confident that they will give you a response in the next few days. I have already escalated it to the responsibles.
    I am doing calls and Webinars 26 hours a day. This is what is required for selling right now. This is the reason why I am not being able to invest time on you these weeks. However, as I told you, I am taking care internally.”

    Best Regards

    J.G.H | SMA Ibérica|Sales Manager

    But the SMA Sales manager did have time to give me sales advice, ok it was not correct information, “Pode conectar duas baterias num SBS. Ele é um inversor de baterias “multistring”
    Pode ligar em qualquer uma das fases tal e como comentou, já que o medidor trifásico calcula e resta as fases. Exemplo se voce tiver: F1: 3 kW / F2: 0 kW / F3: -3 kW, o medidor vai medir 0 kW.” and now it cost us about 20.000 Euros because my clients do not want the SBS and the batteries anymore, and of course, how can blame them, no back up or solutions from SMA!! Still waiting.

    And now I received a text message from the APESF in Lisbon with the following text; “So there is no net metering and there will never be” L. B. / APESF. ASESF stands for Ass. Portuguesa de Empresa do sector Fotovoltaico.

    Now I would like to hear some response of SMA-Iberica or SMA headquarters in Germany.

    Thank you already for the time and hopefully the response.

    Best Regards,
    Alfred

    Reply
    • Christiane Keim
      Christiane Keim says:

      Hello Mr. Op den Brouw,

      Your matter is discussed internally.
      Please apologize any additional delay.
      We will get back to you asap.

      Sunny regards
      Christiane

      Reply
  7. Alfred
    Alfred says:

    Good afternoon Madam Keim,
    I now understand my Malaysian client, he told me that he would not want SMA products at his villa, because the technical after-service is terrible. Now I have to admit, it is, and it is very sad because your products are good, BUT let me tell you something, you would not survive if you do not have your after-sale service right. And we have decided to lower our sales of SMA products and will go to Sungrow and Fronius products because of their excellent after-sale service. p.s Madam Keim, still no news received from SMA, not SMA Germany, SMA Iberica, and SMA Portugal. And a pity your censure my other comments on this block, I thought we can share good and bad news here. But properly you do not like bad news.

    Reply
    • Christiane Keim
      Christiane Keim says:

      Hello Mr. Op den Brouw,

      Please be assured that we have well received your post here.
      And please be also assured that no post ever will be deleted.
      The sales contact responsible for the requested area will get back to you.

      Sunny regards
      Christiane

      Reply
  8. Karl Jull
    Karl Jull says:

    Hi Christiane, has this now been resolved. I am in the process of purchasing a Sunny Boy storage 3.7 unti together with an LG CHEM 10 battery to be used on a tri-power 4.0 inverter.
    I live in Spain and do not have receive money for feeding back to the grid.
    Will this work?

    Thanks

    Reply
    • Christiane Keim
      Christiane Keim says:

      Hello Karl,

      You will need to consult with your qualified installer to advise whether your components are appropriate for your local requirements.
      In general, it’s a good idea to try self-consuming as much solar energy as possible rather than feed it into the grid.
      This is particularly important when you do not receive a feed-in tariff. Installing a Sunny Boy Storage can help you store your solar energy and make it available when you need it. This is an effective way to increase your self-consumption!

      Sunny regards
      Christiane

      Reply
  9. Karl Jull
    Karl Jull says:

    Not sure what happened to my previous post.
    Can you tell me if this issue has been fixed as I am looking to install an SMA Storage 3.7 on my Tripower 4.0 system in Spain.

    Regards

    Reply
    • Christiane Keim
      Christiane Keim says:

      Hello Karl,

      Sorry for the slight delay in getting back to your post.

      Sunny regards
      Christiane

      Reply

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