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The Solis Smart Port Explained: One Port, Three Functions

When Solis released its new range of S6 hybrid inverters last year, alongside the headline upgrades in performance and power as well as input and compatibility, one new feature stood out for its versatility and ingenuity: the Smart Port.

It’s a simple idea with significant impact. Without additional hardware or complex redesigns, the Smart Port gives installers a flexible way to integrate storage, manage loads and even AC-couple the inverter to existing PV systems to add storage — all through one multifunctional connection.

Understanding the AC Ports on a Solis Hybrid Inverter

The Solis S6 hybrid inverters include the following AC outputs:

AC Grid Port(s): for standard grid connection.
AC Backup Port: a primary backup supply for grid outages. Unlike other solutions, it needs no additional hardware; the backup circuit can be wired directly into the port. In the case of whole-home backup, Solis does advise the use of an ATS, or Automatic Transfer Switch, so the load switches back to the grid in the case of a firmware update of the inverter.
Smart Port: a multifunctional port that unlocks versatile applications depending on the site requirements, including extended backup, intelligent load management and retrofitting energy storage.

What Can the Smart Port Do?

The Smart Port brings flexibility to both new installations and retrofit sites. It can be configured in a number of different ways:

1. As a Generator Input for Extended Backup

During extended grid outages, the Smart Port can be configured to connect an external generator for charging batteries with an automatic start/stop contact control.

When grid power fails and the system switches over to the battery supply, the Solis hybrid inverter continuously monitors the battery State of Charge, or SOC. If the SOC drops to a preset lower threshold, for example 30%, the inverter signals the generator to start. The generator then charges the battery at full output. Once the upper SOC threshold is reached, for example 80%, the inverter signals the generator to shut down.

This cycle continues until grid power is restored.

Caption: Using the Solis S6 Hybrid Inverter Smart Port to connect a generator for extended backup.

When using the Smart Port as a generator input for the hybrid inverter, it’s important to note that the generator rating must not exceed the nominal power of the Solis inverter to prevent overcurrent and system damage.

2. As Secondary Backup

The Smart Port can also operate as a secondary backup output for non-critical loads. This allows you to create tiered backup without adding complexity or additional hardware.

In this configuration, appliances such as washing machines, boilers, EV chargers or air conditioning units can be powered while the battery remains above a defined threshold. If the SOC drops below that level, the output switches off, preserving energy for essential circuits.

Caption: Using the Smart Port for secondary battery backup during a grid outage for non-critical loads.

3. AC-Coupling to Add a Battery to an Existing Solar PV System

For retrofit storage projects, the Smart Port becomes particularly valuable. By using the port, the Solis S6 hybrid inverters can be AC-coupled to an existing PV system, regardless of brand. It doesn’t matter whether the site already has a string inverter, microinverters or an optimiser-based system.

Caption: Using the Smart Port to configure an AC-coupled battery storage system.

The original PV inverter is connected to the Solis S6 hybrid via the Smart Port. The battery is charged following AC-DC conversion from the S6 hybrid, and the load and grid connection, via a smart meter, comes from the S6 AC port(s). Additional PV modules can also be added to the site via the S6 inverter if required.

In this setup, the Solis hybrid inverter effectively becomes the energy management controller for the site. The PV inverter supplies energy into an AC network. The Solis hybrid can use that energy to power loads directly or charge the battery through AC-to-DC conversion.

If zero export mode has been selected, once the battery is full, the Solis hybrid can regulate the output of the existing PV inverter by frequency adjustment at the Smart Port, also known as PV limiting. This helps support compliance with export restrictions while maximising on-site energy use.

Power Limits to Note

To prevent overcurrent and protect the system, there are a couple of power limits to note:

For a three-phase external inverter, its rated power must not exceed the nominal power of the Solis hybrid inverter.
For a single-phase external inverter, its rated power must not exceed one third of the nominal power of the Solis three-phase hybrid inverter.
For a single-phase external inverter connected to a Solis single-phase hybrid inverter, its rated power must not exceed the nominal power of the Solis hybrid inverter.

A Versatile Addition to the Solis S6 Hybrid Inverters

With the ability to operate in both on-grid and off-grid scenarios, Solis S6 hybrid inverters are already a versatile choice. The addition of Smart Port makes them even more adaptable, opening up new opportunities for customers.

Suitable for both new and existing installations, the Hybrid S6 Smart Port allows you to add site-specific capabilities to make the most out of a renewables installation without a major system redesign and with minimal additional hardware.

If you’d like guidance or support specifying Solis hybrid systems for retrofit or AC-coupled projects, our team is happy to help.

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