Technical Guide • Solar • EV
Charging Your EV with Solar Panels: Does It Work in Sydney?
If you're comparing your options, see our EV charger installation across Sydney for a free site assessment and fixed-price quote.
Yes — and it’s the single strongest financial case for installing a smart EV charger. A Sydney home with 6.6 kW of solar can charge an EV for effectively $0 per km on surplus solar, versus $5–$7 per 100 km on grid power. But you need the right charger, the right setup, and realistic expectations about how much solar surplus is actually available. Here’s the practical guide from electricians who install both solar and EV systems.
Primary sources: Clean Energy Regulator small-scale renewable scheme · AS/NZS 4777 grid-connection standard.
How Solar and EV Charging Actually Work Together
Your solar panels generate DC power → your inverter converts it to AC → your home uses what it needs → the surplus exports to the grid at 3–8¢/kWh. Without a smart EV charger, that surplus is gone. With a smart charger (Zappi, Ocular IQ, Evnex E2, Fronius Wattpilot), a CT clamp on your meter board monitors real-time energy flow. When surplus exceeds a threshold (typically 1.4 kW minimum for single-phase charging), the charger diverts it into the EV instead of exporting it. You're charging your car with energy that would otherwise have earned you 5¢.
Do You Need a Special Charger for Solar?
Yes — for solar divert. A basic Type 2 charger can't "see" your solar production. It charges at full rate from whatever power is available (grid + solar mixed). A solar-smart charger has a CT clamp + firmware that:
- Monitors your real-time export in watts
- Modulates the charger's draw to match available surplus
- Switches between modes: solar-only (Eco+), solar-boosted (Eco), or full-speed (Fast)
The key brands with native solar divert in Australia: myenergi Zappi (3 modes, CT clamp included), Evnex E2 (Eco mode), Ocular IQ Home Solar (built-in solar awareness), Fronius Wattpilot (best with Fronius inverters — native integration, no CT clamp needed).
What the Electrician Checks When Connecting a Charger to Your Solar System
- Inverter capacity and current output. Your solar system's peak output determines the maximum divert rate. A 5 kW inverter on a good day produces ~4 kW of surplus after household use — enough for ~5.5 kW of EV charging (with efficiency losses).
- CT clamp placement. The CT clamp goes on the main supply cable at the meter board — not on the solar circuit. It reads net import/export, which is what the charger uses to calculate surplus. Incorrect placement = incorrect divert behaviour.
- Phase matching. Single-phase solar on a single-phase home is straightforward. Three-phase solar on a three-phase home needs the charger on the same phase as the largest solar contribution — or a charger that reads all three phases (Zappi does this natively).
- Export limit compliance. Ausgrid and Endeavour Energy have export limits (typically 5 kW per phase for single-phase). Smart EV charging that captures surplus before export helps you stay within these limits while maximising self-consumption.
Real Savings Comparison — Solar vs Grid vs Off-Peak
Want to capture these solar savings on your own EV charger?
SRS installs Zappi, Evnex, and Tesla Wall Connector with full solar diversion configured on the first visit. Licensed, insured, 24/7 across Sydney.
Get a Solar EV Quote →| Charging source | Cost per 100 km | Annual cost (15,000 km) |
|---|---|---|
| Surplus solar (smart charger divert) | ~$0 – $1.50 | $0 – $225 |
| Off-peak grid (ToU plan, scheduled) | ~$3.00 – $4.50 | $450 – $675 |
| Flat-rate grid | ~$5.50 – $7.00 | $825 – $1,050 |
| Peak-time grid | ~$9.00 – $11.00 | $1,350 – $1,650 |
| Equivalent petrol (8L/100km @ $2/L) | ~$16.00 | $2,400 |
The savings from solar divert vs flat-rate grid: approximately $600–$1,050 per year. The smart charger premium over a basic unit (roughly $600) pays back in under 12 months. After that, every kilometre charged on solar surplus is effectively free.
What If You Don't Have Solar Yet?
If you're buying an EV charger and considering solar: install them together. A combined solar + EV charger install by the same electrician saves one site visit, coordinates the switchboard work, and ensures the CT clamp and charger are configured correctly from day one. The combined cost is lower than two separate projects.
If solar is 2+ years away: install a basic charger now and upgrade to a solar-smart charger when solar goes on. Alternatively, install a smart charger now (Evnex E2 Flex offers "grid now, solar later" — no hardware change needed to enable solar divert when panels are added).
Frequently Asked Questions
Can I charge my EV from solar panels?
Yes — with a solar-smart charger (Zappi, Evnex E2, Ocular IQ, Wattpilot) that diverts surplus solar into the EV instead of exporting it. A basic charger can't do this — it draws from whatever power is available without distinguishing solar from grid.
How much does it cost to charge an EV on solar?
Effectively $0–$1.50 per 100 km when charging on surplus solar. Compare to $5.50–$7 per 100 km on flat-rate grid, or $16 per 100 km for equivalent petrol. Annual saving vs grid: $600–$1,050 for a 15,000 km/year driver.
Do I need a special charger for solar?
For solar divert (automatically using surplus solar), yes. Brands with native solar integration: myenergi Zappi, Evnex E2 (Eco mode), Ocular IQ Home Solar, Fronius Wattpilot. A basic Type 2 charger charges from whatever power is available but can't preferentially use solar.
Does my inverter brand matter for solar EV charging?
For most smart chargers, no — the CT clamp reads net energy flow regardless of inverter brand. Exception: the Fronius Wattpilot integrates natively with Fronius inverters without needing a separate CT clamp — tighter integration and easier setup if you already have Fronius.
How much solar do I need to charge an EV?
A 6.6 kW solar system on a Sydney roof generates about 25 kWh/day on average. A typical EV daily commute (40 km) needs about 8 kWh. So a 6.6 kW system can comfortably cover daily EV charging from surplus — with energy left over for the house. A smaller system (3-4 kW) can partially charge the EV but won't cover a full commute on solar alone.
Can I charge my EV on solar if I have a battery?
Yes — and a home battery adds flexibility. The battery stores excess solar during the day and can charge the EV overnight when the panels aren't producing. However, a battery adds $8,000–$15,000 to the system cost, which changes the payback math significantly. For most Sydney households, a smart charger with solar divert (no battery) provides the best ROI.
Want to charge your EV on sunshine?
We install EV chargers with solar integration — CT clamp configured, charger matched to your inverter, and divert modes set up on the first visit.