Single-Phase vs Three-Phase Power: What It Means for Solar, Battery and EV Charging

Most Victorian homes are wired for either single-phase or three-phase power, and the difference has a bigger impact on your clean energy options than most homeowners realise.

Single-phase supply is the standard for smaller and older homes. It comfortably supports a solar system, a 7kW EV charger, and a home battery — but there's a ceiling on how much power you can draw or export at once.

Three-phase supply splits the load across three separate circuits, which is common in larger homes, newer builds, and properties with ducted air conditioning or a pool. It raises that ceiling significantly.

For batteries specifically, three-phase properties can support larger systems — stacking multiple modules well beyond what a single-phase connection allows — because the extra capacity is there to charge and discharge without tripping limits.

For EV charging, three-phase unlocks 22kW charging speeds instead of being capped around 7kW on single-phase, cutting a typical overnight charge time significantly.

You can usually tell which supply you have by checking your switchboard for three incoming red service fuses instead of one, or by checking a recent electricity bill. If you're unsure, our electricians confirm it as a standard part of every site assessment.

If you're planning a larger battery or a fast home EV charger, it's worth finding out early — in some cases, upgrading from single to three-phase is straightforward and opens up meaningfully more headroom for your system.