The Solis S6-EH3P inverter has a dedicated GEN port (labelled "Input Generator" in the datasheet). In addition to connecting a generator, this port can accept AC-coupled PV — for example, a separate grid-tied inverter installed alongside the Solis hybrid.
When AC-coupled PV is connected to the GEN port, the Solis internally adds that power to its own output. From FlexiO's perspective, TotalInvPower includes both DC PV (through the Solis MPPT) and the GEN port power, but FlexiO measures DC PV separately and does not automatically account for the GEN port contribution.
If this is not configured correctly, FlexiO will underestimate total PV production. This leads to:
-
Incorrect energy readings in the MyFlexiO app (PV production appears lower than actual)
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Incorrect homeload calculation
-
Incorrect curtailment behaviour — the EMS may set an output setpoint that causes the inverter to cut all output, forcing homeload to be covered entirely from the grid
When this applies
This configuration is required when both of the following are true:
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The installation has a separate (retrofit) PV inverter whose AC output is connected to the Solis GEN port
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The Solis inverter model is S6-EH3P
It does not apply to DC PV strings connected directly to the Solis MPPT inputs, or to installations where the GEN port is used only for a generator.
How to configure
In the FlexiO installer portal, open the device configuration and complete the Retrofit Panels section:
|
Field |
Value |
|---|---|
|
Peak Power |
Peak output of the AC-coupled PV installation (Wp per array) |
|
Solar Panels Tilt |
Roof tilt in degrees (0 = horizontal, 90 = vertical) |
|
Solar Panels Orientation |
Azimuth in degrees (−90 = East, 0 = South, 90 = West) |
|
Measurement type |
InverterPvRetro |
Setting Measurement type to InverterPvRetro tells FlexiO to derive the AC-coupled PV production directly from the Solis GEN port reading, rather than estimating it. This is the correct mode when AC-coupled PV is connected to the Solis GEN port.
It is important to configure all 3 PV-arrays seperatly. The 2 PV-strings as 2 seperate Hybrid PV arrays.
The PV-array, connected to the GEN-Port, as Retrofit PV.
Do not select EastronPvRetro unless a dedicated Eastron power meter is installed on the AC-coupled PV circuit. Using the wrong measurement type will cause the same underestimation problem.
Verification
After saving the configuration, confirm the setup is working correctly:
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Open IO Diagnostics for the device and check that no errors related to inverter or meter readings are present.
-
At a time when the AC-coupled PV system is producing, verify in Grafana or the app that
inverterPVRetroshows a value consistent with expected production from the AC-coupled array. -
Confirm
TotalInvPowerreflects only the Solis hybrid output (DC PV + battery), not the sum of both systems.
Curtailment: If the installation is subject to grid injection limits, do not enable curtailment until the GEN port configuration has been verified. With incorrect configuration, the EMS calculates curtailment setpoints based on underestimated PV, which can drive inverter output to near zero while the AC-coupled PV continues to produce independently.