Understanding how your solar panels and battery are connected determines how the control features in Amber's SmartShift automation work.
What is the difference between AC-coupled and DC-coupled systems?
The difference lies in where the battery connects relative to the solar power conversion:
| Coupling type | Energy Path & Inverters | SmartShift Control |
|---|---|---|
| DC-Coupled | One inverter: Solar power (DC) goes directly to the battery (DC) or is inverted to power your home (AC). The solar and battery share a single hybrid inverter. | Full control: SmartShift can automate your battery and activate solar curtailment on the single device. |
| AC-Coupled | Two Inverters: Solar power (DC) is converted to AC by the solar inverter, and then back to DC by a separate battery inverter/charger. This is common on retrofitted systems. | Battery control only: SmartShift can automate your battery. Automated solar curtailment is only possible if the other inverter is also compatible with SmartShift. |
How can I tell if my system is AC- or DC-coupled?
The easiest way is to look at your physical setup:
- One inverter (DC-Coupled): If you have a single unit that handles both the solar and the battery, you likely have a DC-coupled system. This is common in new installations where you’ve had solar and battery installed at the same time.
- Two inverters (AC-Coupled): If you have two separate units—one connected to the panels and one connected to the battery—you likely have an AC-coupled system. This is typical when adding a battery to an existing solar system.
What about "hybrid" systems?
The term "hybrid" primarily describes the inverter device itself. A hybrid inverter is simply an inverter that is designed to manage both solar energy (DC) and battery energy (DC) in a single unit. These inverters are the foundation of a DC-coupled setup.
For some retrofitted installations, a new hybrid inverter may be installed. If this inverter is AC-coupled to your existing solar inverter, the setup behaves like an AC-Coupled system. However, if new panels are installed and DC-coupled to the new hybrid inverter, the system's control becomes split: SmartShift can activate solar curtailment for the new DC-coupled panels, but curtailment for the older, AC-coupled panels remains dependent on the compatibility of the original inverter.
My system is AC-coupled, now what?
First things first, check if your other device is listed on our Compatibility Checker.
Yes: Great! This simply means that you need to register your other inverter to enrol in SmartShift if you haven't already.
No: Alright, this means that we won't be able to help you avoid negative FiT through solar curtailment. Read on for the implications of this.
My system is AC-coupled and my other inverter is not on the compatibility list. Does that mean SmartShift won't work?
If your solar inverter is incompatible, we won't be able to activate solar curtailment. This means you may be exposed to negative Feed-in Tariffs (FiT) during periods of high grid supply and low demand e.g. when lots of homes are exporting excess solar to the grid during the day when electricity demands tend to be lower. The overall outcome depends on how much of that excess solar energy you can self-consume or store.
Crucially, the SmartShift battery automation still works and can help by exporting energy ahead of negative FiT periods to free up battery capacity. If you are concerned about negative FiT exposure, you may want to consider strategies like load-shifting to absorb the excess solar or adding more battery storage.
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