Electric Vehicle Charging at Home: WA Tariffs, Costs, and Smart Strategies

More Western Australians are switching to electric vehicles every month. But how much does it actually cost to charge at home? And which Synergy tariff gives you the cheapest charging? Let's break it down.

Home Charging Basics

Charging Levels

| Level | Power | Charging Speed | Typical Use | |-------|-------|---------------|-------------| | Level 1 | 2.4 kW (standard outlet) | ~12 km/hour | Emergency/overnight top-up | | Level 2 | 7.4 kW (dedicated circuit) | ~40 km/hour | Recommended home charger | | Level 2 | 22 kW (three-phase) | ~120 km/hour | Fast home charging |

Most Perth households install a Level 2 single-phase charger (7.4 kW) — it can fully charge a typical EV overnight.

Charger Installation Costs

Charger unit: $800–$2,500 (depending on brand and features)
Installation: $500–$1,500 (electrical work, dedicated circuit)
Total typical cost: $1,300–$4,000

Smart chargers (that can schedule charging times) are recommended for tariff optimisation.

The Cost of Charging Your EV

How Much Electricity Does an EV Use?

Most EVs consume between 14–20 kWh per 100km driven. The average Perth household drives about 40 km per day, requiring approximately 6–8 kWh of charging.

Monthly charging for a typical commuter:

40 km/day × 30 days = 1,200 km
At 16 kWh/100km = 192 kWh/month

Charging Cost by Tariff

| Tariff | Rate During Charging | Monthly Cost (192 kWh) | Annual Cost | |--------|---------------------|----------------------|-------------| | A1 (flat rate) | ~30.8 c/kWh | ~$59 | ~$710 | | Midday Saver (midday) | ~15 c/kWh | ~$29 | ~$346 | | Smart Home (off-peak) | ~18 c/kWh | ~$35 | ~$415 | | EV Add-On (super off-peak) | ~10 c/kWh | ~$19 | ~$231 | | Solar self-consumption | $0 | $0 | $0 |

Compare this to petrol: a similar-sized car doing 8L/100km at $1.80/L costs about $173/month — that's $2,074/year.

Synergy's EV Tariffs

EV Add-On Tariff

Synergy offers a dedicated EV charging tariff that provides a super off-peak rate:

Super off-peak period: Typically midnight to 6am
Rate: Approximately 10 c/kWh during super off-peak
Requirements: Separate meter or smart meter capable of recording EV usage
Best for: Overnight charging when you don't have solar

Smart Home Plan

The Smart Home Plan offers time-of-use pricing that benefits EV owners:

Off-peak rate (9pm–7am): Lower than A1 flat rate
No dedicated EV meter required
Also benefits general household usage

Midday Saver + Solar

If you have solar and charge during the day:

Grid rate during midday: ~15 c/kWh (if solar isn't enough)
Solar self-consumption: Effectively free
Best for: Work-from-home or daytime charging setups

Smart Charging Strategies

Strategy 1: Charge from Solar (Best Savings)

If you have a 6.6kW+ solar system, charge your EV during the day when the sun is shining.

Cost: $0 (solar self-consumption)
Requirements: Daytime charging capability (work from home, or plug in when you get home and the sun is still up)
Smart charger feature: Some chargers can detect excess solar and only charge from surplus

Annual savings vs A1 tariff: ~$710

Strategy 2: EV Add-On Night Charging

For households that drive during the day and charge overnight:

Schedule charger for midnight–6am
Super off-peak rate applies
Cost: ~$231/year for typical commute
Annual savings vs A1 tariff: ~$479

Strategy 3: Solar + Battery + EV

The ultimate setup:

Solar charges battery during the day
Battery powers the house in the evening
EV charges from grid during super off-peak (cheapest rate)
Or: EV charges from solar during the day

Combined annual cost for EV charging: As low as $50–$100/year with optimised scheduling.

Sizing Your Solar System for an EV

Adding an EV typically adds 6–8 kWh of daily electricity demand. To cover this with solar:

Additional solar needed: 2–3 kW of panels
Current system is 5kW? Upgrade to 7–8kW
Current system is 6.6kW? May already have enough surplus

Use BillWise's scenario tool to model the exact impact on your bills.

V2H and V2G: The Future

Vehicle-to-Home (V2H) and Vehicle-to-Grid (V2G) technology is emerging:

V2H: Use your EV battery to power your home during peak hours
V2G: Export power from your EV back to the grid for credits
Status in WA: Not widely available yet, but some vehicles (e.g., certain models) support it with compatible chargers

When V2H becomes mainstream, your EV battery (typically 60–100 kWh) could serve as massive home energy storage, far larger than any dedicated home battery.

Charger Recommendations for WA

For Perth households, we recommend:

Budget option:

Any 7.4kW Mode 3 charger with timer
Set timer for your cheapest tariff period
From ~$800 installed

Smart option:

Solar-aware charger (e.g., Zappi, Tesla Wall Connector)
Automatically adjusts charging to use excess solar
From ~$1,500 installed

Premium option:

Three-phase 22kW charger with solar integration
Fast charging + full smart control via app
From ~$2,500 installed

Calculate Your EV Charging Costs

Your actual costs depend on your tariff, solar system, driving patterns, and charger setup. BillWise can model it all:

Upload your bill — We'll see your current tariff and usage
Run an EV scenario — Add EV charging to see the impact
Compare tariff options — Find the cheapest charging tariff for your profile

Start your EV cost analysis →

The bottom line: charging an EV at home in Perth costs a fraction of running a petrol car, and with the right setup, you can charge for almost nothing.

EV Charging at Home: Everything You Need to Know -- Our complete guide to home EV charging setup, equipment, and installation in WA.

Ready to compare EV charging costs? Calculate your ROI → — includes petrol vs EV comparison with live FuelWatch prices so you can see exactly what switching saves you.