Example of Limiting of the Active Power Feed-In to 70%

Limitation of the active power feed-in to 70% of the nominal PV system power

Due to high levels of solar irradiation, the system (system size: 10 kWp / feed-in limit: 7 kW) can currently produce 90% of the nominal PV system power.

  • 20% of the nominal PV system power is currently being consumed by loads in the household. The remaining amount of 70% of the nominal PV system power is being fed into the utility grid.
    No limitation of PV generation is required.

  • A load is switched off and only 10% of the nominal PV system power is consumed in the household. As a result, 80% of the nominal system power is available for feed-in to the utility grid – more than allowed.
    The Sunny Home Manager reduces PV generation from the theoretically possible 90% of nominal PV system power to 80%. 70% of the nominal PV system power continues to be fed into the utility grid.

A Limiting of the active power feed-in can be entered as follows:

  • Limitation to a fixed value of the nominal system power in kW (setting range: 0 kW to 0.99 x nominal system power kW)
    If there is also a limit due to external setpoints in addition to this setting, the limit is set to the smallest value.

  • Limitation to a percentage of the nominal system power (setting range: 0% to 99%)
    If there is also a limit due to external setpoints in addition to this setting, the limit is set to the smallest value.

  • Zero export – blocks grid feed-in into the utility grid (setting: 0% or 0.000 kW of the nominal system power). Due to control cycle times, an inevitable remaining quantity of energy might nevertheless be fed into the utility grid.

If a battery or hybrid inverter is part of your system, after a defined limit of the nominal system power (< 10 % of or the corresponding kW value of the system power) is set, you can include the battery or hybrid inverter in the energy management and use the surplus energy to charge the battery-storage system.

You can use a function test to check the limitation of the active power feed-in:

  • In the Limitation of active power feed-in section, click on the option button max. xx kW and enter the value 0. Thus, the Sunny Home Manager immediately limits the active power when the inverters starts feeding into the utility grid.

Supported inverters for the limitation of the active power feed-in to 0%

The limitation of the active power feed-in to 0% is only supported by inverters that support the fallback function. In the event of a communication failure between the Sunny Home Manager and the inverter, the inverter reverts to an output power of 0 watts. For more information see the inverter manual at www.SMA-Solar.com.

Monitoring of the PV system and the dynamic limitation of the active power fed into the utility grid are not possible with inverters from other manufacturers. In this case, verify whether operation of the PV system without dynamic active power limitation is permitted in the given country, or whether dynamic active power limitation can be performed independently by the inverter itself.

    Information Regarding Limiting of the Active Power Feed-In
    Configuring Limitation of Active Power Feed-In