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

by Daniel Chung (guest post), , 4 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.


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?


  1. Avatar
    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?

    • 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

  2. Avatar
    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.

    • 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


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