EV charging
Charging an electric car from your solar
An EV is one of the best uses for daytime solar you'd otherwise export for 2c. The trick is charging it when the panels are producing, which isn't always when the car is at home.
How much power does an EV use?
Most electric cars use somewhere around 0.15 to 0.2 kWh per kilometre, with larger cars and SUVs at the higher end. At 40 km a day that's roughly 6 to 8 kWh a day, about half of what a typical WA home uses.
When to charge
- During the day, from solar: the cheapest option. The power would otherwise be exported for 2c. Works best if the car is home during the day: working from home, weekends, a second car.
- From the battery at night: possible, but usually not the best use of it. A 7 kWh charge can take a big share of a home battery that would otherwise be running the house through the evening.
- From the grid overnight: on the right plan, it's cheap enough.
Synergy's EV plan
Synergy's Electric Vehicle Add On plan has time-of-use rates. As at 1 July 2026 they include 8.85c per kWh from 9am to 3pm and 19.92c overnight from 11pm to 6am, with a much higher rate from 3pm to 9pm and a supply charge of 132.78c a day. For a household that can charge in the middle of the day or overnight, it can work out cheaper than the standard A1 plan's 33.26c per kWh. Check your whole household's usage against it, not just the car's.
Choosing a charger
- A standard power point charges at around 2 kW. That's fine for short daily trips, but slow.
- A wall charger on single-phase power typically charges at up to about 7 kW.
- On three-phase power, up to 22 kW if the car can take it. Many can't.
- A solar-aware charger can follow your panels' output and only charge from surplus solar. That's the setting that makes daytime charging cheap without you thinking about it.
Plan it with the solar, not after
An EV charger is a big load on the switchboard and usually needs its own circuit. If you're installing solar and a battery now and an EV is likely in the next few years, size the panels for it and run the cabling while the electrician is already there. It's cheaper than coming back.
Want the numbers for your house?
Send us your latest Synergy bill and we'll size a system from your actual usage, show every rebate as its own line, and tell you what we can and can't offer before you sign anything.