EV home charging in Perth: costs, tariffs, and setup guide

Charging your EV at home is simpler and cheaper than it sounds — particularly in Perth where Synergy's EV Add-On tariff and the state's strong solar resource combine well. Here's what you need to know before plugging in.

How EV charging works at home

Electric vehicles charge via two primary methods:

AC charging (Level 1 and Level 2): The charger converts mains AC electricity to the DC that the battery stores. Most home charging uses a dedicated wall box (Level 2, single or three-phase AC) for faster charging speeds.

DC fast charging: Found at public charging stations, not suitable for home installation. Much faster but uses different infrastructure.

For home use, the decision is between:

Mode 2 (socket / granny charger): A cable from a standard power point (10A = 2.4kW) via a smart portable EVSE. Adds roughly 10–15km of range per hour. Slow but requires no installation beyond a good-quality power point circuit.

Mode 3 (dedicated wall box): A hardwired or plug-in wall-mounted unit. Typical home wall boxes run at 7.4kW (single-phase, 32A) or 11–22kW (three-phase). At 7.4kW, a depleted 75kWh battery (common mid-sized EV) reaches full in approximately 10 hours — overnight.

The Synergy EV Add-On tariff

Synergy's EV Add-On tariff is an add-on to either the A1 (flat rate) or Midday Saver tariff. It provides a discounted overnight electricity rate for a dedicated EV charging circuit.

EV Add-On rate from 1 July 2026: 19.92c/kWh overnight (11pm–7am)

At 19.92c/kWh, charging a 75kWh battery (from depleted to full) costs approximately $14.94 — roughly equivalent to filling a ~45L petrol tank at $0.33/L. For the typical Perth driver doing 14,000km/yr in an EV using 18 kWh/100km, annual home charging costs approximately:

14,000km × 18 kWh/100km = 2,520 kWh/yr

2,520 kWh × $0.1992/kWh = $502/yr to charge at EV Add-On rates

Compare that to a petrol equivalent at $2.10/L and 8L/100km: $2,352/yr in fuel.

Requirement: The EV Add-On rate applies to a dedicated metered circuit for EV charging — not to your whole-home electricity use. The dedicated circuit is separately metered or sub-metered so Synergy can apply the discounted rate only to EV charging consumption. Installation requires an electrician to install the dedicated circuit and compatible meter point.

You continue paying A1 or Midday Saver rates for all other household electricity.

Wall box installation cost

A dedicated EV wall box installation in Perth typically costs:

Wall box unit: $500–$1,500 depending on brand and power level (7.4kW single-phase is most common for residential)

Installation (electrician): $500–$1,200 for a straightforward install (switchboard to garage, single-phase). More complex installs (three-phase power, long cable runs, switchboard upgrades) cost more.

Total typical range: $1,000–$2,500 fully installed for a single-phase 7.4kW charger

Popular brands in the Perth market include Wallbox, Zappi, EVNEX, and Myenergi. Smart chargers in this category support scheduling (set to charge only during EV Add-On window), solar integration, and monitoring.

EV charging + solar: the optimal setup

Solar panels and home EV charging pair well in Perth — but the timing requires thought.

Scenario 1: A1 tariff + solar (no EV Add-On)

If you're on A1 and have solar, you can charge your EV during the day using your solar generation — effectively at zero marginal cost rather than exporting at the 2c/kWh DEBS off-peak rate. This requires either being home during the day or having a smart charger that detects solar export and starts charging when excess is available.

Scenario 2: EV Add-On + overnight charging

The EV Add-On 19.92c/kWh overnight rate is cheaper than Midday Saver's peak rate (55.33c/kWh) but more expensive than Midday Saver's super off-peak rate (8.85c/kWh, 9am–3pm) or solar self-consumption (effectively free).

If you charge overnight on EV Add-On, you're paying 19.92c/kWh. If you instead schedule your charging for the Midday Saver super off-peak window (9am–3pm), you'd pay 8.85c/kWh — saving over $280/year for the typical EV driver.

Scenario 3: Solar + Midday Saver + daytime charging (optimal)

For Perth households with solar panels on Midday Saver, the best EV charging approach is scheduling the car to charge during the 9am–3pm window. In this window:

• Your solar panels are likely generating at near-maximum capacity
• The Midday Saver rate is 8.85c/kWh (vs 33.26c/kWh on A1)
• If solar generation exceeds house + EV load, excess is exported at 10c/kWh (peak DEBS not available midday — the peak window is 3pm–9pm)

A smart EV charger like the Zappi can automatically throttle charging based on available solar export — consuming exactly as much solar as you're currently generating, with no or minimal grid draw. This effectively charges your car on solar at zero marginal cost.

Net effect: A Perth household with solar + Midday Saver + smart charger can charge their EV almost entirely on solar generation for most of the year — particularly in summer months when solar generation significantly exceeds typical household loads.

Do you need three-phase power?

Most Perth residential properties have single-phase power. A 7.4kW wall box on single-phase charges a 75kWh battery in approximately 10 hours — overnight charging works fine.

Three-phase power (available on some newer properties and upgradeable through Western Power for a fee) allows 11kW or 22kW charging speeds. At 22kW, the same 75kWh battery charges in under 4 hours. For most households, this speed is unnecessary — overnight charging is sufficient.

Three-phase also allows larger solar inverter capacity (beyond the 5kW single-phase limit). If you're installing both solar and an EV charger and your property has three-phase, it opens more options.

Installing the dedicated circuit: what's involved

1. Electrician assessment: Determines whether your switchboard has spare capacity, required cable run length, and any upgrades needed.
2. Wall box selection: Choose a unit compatible with your car and charger requirements.
3. Electrician installation: Installs the dedicated circuit, wall box, and any required sub-meter.
4. Synergy EV Add-On application: Apply through My Synergy once the dedicated circuit is installed. Synergy confirms the meter configuration before activating the discounted rate.

The whole process from electrician assessment to EV Add-On activation typically takes 2–4 weeks including Synergy's application processing.

Running costs summary

| Charging scenario | Cost per kWh | Annual cost (14,000km, 18kWh/100km) | |---|---|---| | Petrol equivalent (8L/100km at $2.10/L) | — | $2,352 | | A1 tariff, grid electricity | 33.26c | $838 | | EV Add-On, overnight | 19.92c | $502 | | Midday Saver super off-peak | 8.85c | $223 | | Solar self-consumption (daytime) | ~0c | ~$0 |

The combination of solar + Midday Saver + smart charging captures most of the value in the bottom two rows during daylight hours, with EV Add-On or Midday Saver off-peak rates for evening and overnight top-ups.

The EV Add-On tariff rate is effective 1 July 2026. EV charging costs depend on vehicle efficiency, usage patterns, and charging schedule. Installation costs are indicative — obtain quotes from licensed electricians. Synergy EV Add-On requires a dedicated metered circuit — standard power points on a shared circuit do not qualify.