How much solar an EV needs
Work it out from your car's efficiency and your driving. A car using 15 kWh per 100 km that drives 30 km a day needs 4.5 kWh a day. On Clean Energy Regulator ratings, each kW of panels in Sydney, Brisbane, Adelaide or Perth averages 3.8 kWh a day across the year, and 3.2 kWh in Melbourne and Hobart. So that driving needs a little over 1 kW of extra panels, on average.
| Daily driving | Energy needed | Panels in zone 3 | Panels in zone 4 |
|---|---|---|---|
| 20 km | 3.0 kWh | 0.8 kW | 0.9 kW |
| 40 km | 6.0 kWh | 1.6 kW | 1.8 kW |
| 60 km | 9.0 kWh | 2.4 kW | 2.8 kW |
What solar charging saves
Every kWh of solar that goes into the car instead of the grid is worth the difference between your usage rate and your feed-in tariff. On the Ausgrid reference price of 33.14c a kWh, 4.5 kWh a day of solar charging saves roughly $544 a year against charging from the grid at that rate, less whatever the same solar would have earned as exports.
Our EV running cost calculator and electricity bills with an EV guide cover grid charging costs.
Setting up solar charging
Pick a solar-aware charger
Smart chargers read your solar output and adjust the charge rate to use only the spare power, or a set mix.
Check single or three phase
A single-phase home can charge at up to about 7 kW; three phase allows more. Most daily driving needs far less.
Plan for days away
When the car is out during the day, charge overnight on an off-peak rate or in a free midday window if your plan has one, such as the Solar Sharer Offer.
EV or home battery?
An EV battery is far bigger than a home battery, but only helps your home if it is plugged in when the sun shines. Vehicle-to-home charging is still emerging in Australia. See whether a home battery is worth it.
Common questions
For 30 to 40 km of daily driving at 15 kWh per 100 km, roughly 1.2 to 1.6 kW of extra panels in Sydney, Brisbane, Adelaide or Perth, and a bit more in Melbourne and Hobart, on Clean Energy Regulator output ratings.
Only at weekends, unless the car is at home. Otherwise charge overnight on an off-peak rate, or use a free or cheap midday window at work or on your plan.
A solar-aware smart charger is the easiest way, because it adjusts the charge rate to your spare solar. Some inverters and apps can do this too.
Sources
Rules and program details come from government sources. Prices are industry averages, named and dated where used. Last checked October 2026. Prices include GST unless we say otherwise.