Reviewed by Lee Gundenswager, Lead Electrician, Lic #92217 Last reviewed
How does solar EV charging work?
A solar-aware charger watches the power flowing through your meter. When your panels export more than the house is using, the charger sends that surplus into the car instead of the grid. As clouds pass or the kettle goes on, it adjusts in real time. In "solar only" modes it pauses when surplus drops below the minimum charging rate; in blended modes it tops up from the grid to keep a minimum rate.
Why it makes sense in Brisbane
Brisbane gets plenty of sun and rooftop solar is common, but feed-in tariffs are low, so every kWh you use yourself is worth far more than one you export. Putting that energy into your car is one of the most valuable things you can do with it. Energex controlled-load tariffs (Tariff 31 and 33) run on a separate circuit with supply only during set hours, so they suit overnight charging but not daytime solar charging. A time-of-use plan on a smart meter is the usual alternative. Your retailer sets the actual rates.
Solar-aware chargers we install
| Charger | How it uses solar | Good to know |
|---|---|---|
| myenergi Zappi | ECO and ECO+ modes follow your surplus using a meter clamp | Popular, flexible, works with most solar systems |
| Fronius Wattpilot | Follows surplus, integrates with Fronius inverters | Neat choice if you already have a Fronius inverter |
| Other smart chargers | Solar modes via add-on meters or apps | Features vary by model; we check before you buy |
| Tesla Wall Connector | Does not follow surplus on its own | Great charger, but not the first pick for solar-matching |
Compare models on our EV charger brands page.
What installation involves
- A dedicated charger circuit from your switchboard, as with any wallbox
- A current clamp (CT) at the meter or main cable so the charger can see your export
- Setup of solar modes, schedules and off-peak top-ups in the app
- Testing and a Certificate of Testing and Compliance
The solar sensor adds a little to a standard install. See the cost guide.
Controlled-load tariffs and solar
Charging on an Energex controlled-load circuit (Tariff 31 or 33) can be cheap overnight, but the circuit only has power at set times, so it cannot follow daytime solar. Most solar households are better off with the charger on the main circuit, a solar-aware mode by day, and a scheduled off-peak top-up when needed.
Solar EV charging FAQs
How much solar do I need to charge an EV?
Any surplus helps, but solar-only charging needs enough spare output to meet the charger minimum, roughly 1.4kW on single phase. A typical Brisbane rooftop system produces surplus on most sunny days, especially in the middle of the day when household use is low. On cloudy days or at night, the charger can top up from the grid on a schedule.
Can I charge my EV from solar if I work during the day?
Partly. Weekends and days at home will be mostly solar, and you can top up overnight on an off-peak tariff for the rest. A home battery can shift some solar into the evening, but using a battery to charge a car is rarely the cheapest use of it. We can help you work out the best mix for your routine.
Do I need a new inverter?
Usually not. Solar-aware chargers such as the Zappi use a current clamp at the meter to see your export, so they work with almost any existing solar system. Some chargers integrate directly with specific inverter brands, which can simplify the wiring.
Can I charge my EV from my solar panels?
Yes. With a solar-aware charger such as a myenergi Zappi or Fronius Wattpilot, the charger watches your export and tops up the car with surplus solar instead of sending it to the grid. It needs a current sensor at your meter or inverter integration. Charging fully on solar works best if the car is home during the day.
What is the cheapest way to charge an EV at home in Brisbane?
Charging from your own surplus solar is cheapest, followed by charging overnight on a time-of-use or controlled-load tariff. Energex controlled-load tariffs (Tariff 31 and 33) run on a separate circuit with supply only during set hours, so they suit overnight charging but not daytime solar charging. A time-of-use plan on a smart meter is the usual alternative. Your retailer sets the actual rates. We can wire the charger to suit whichever plan you choose.
How much will charging add to my power bill?
It depends on how far you drive and when you charge. A typical EV uses roughly 15 to 20 kWh per 100 km, so multiply your weekly distance by that and by your tariff rate. Charging on surplus solar or an off-peak rate keeps the cost well below the price of petrol for the same distance. Check your retailer for current rates.