EV + Solar + Battery for Perth Homes: Charging Costs, ROI and Best Setup in 2026
TL;DR: A Perth EV owner with solar + battery pays around $1.20–$1.80 per 100 km in 2026 — compared with $7–$10/100 km from grid charging only, or $14–$18/100 km at petrol prices. The sweet-spot setup for a typical Perth home with one EV is 10 kW solar + 13.5 kWh battery + 7 kW EV charger, costing $19,500–$22,800 turnkey after rebates. With 40 km/day driving, the system saves $2,800/year on motoring fuel costs alone, plus $4,000+/year on household electricity.
The real cost of charging an EV in Perth
An EV uses around 16–20 kWh per 100 km in real-world driving (a Tesla Model Y averages ~18 kWh/100km, a BYD Atto 3 ~16 kWh/100km). The cost of that energy depends entirely on where it comes from:
| Charging source | $/kWh | $/100 km |
|---|---|---|
| Petrol equivalent (95 octane) | n/a | $14–$18 |
| Grid only, Home Plan A1 | 30c | $5.40–$7.20 |
| Grid only, Smart Home Plan peak (3pm–9pm) | 57c | $10.25–$13.70 |
| Grid only, Smart Home Plan off-peak (9pm–7am) | 9.5c | $1.70–$2.30 |
| Public DC fast charger (Tritium, Evie) | 55–69c | $10–$14 |
| Solar self-consumption only | 0c (your solar) | $0 |
| Solar + battery + occasional off-peak | 2–4c (effective) | $0.40–$0.80 |
The economics of EV charging at home with solar are extreme: roughly 10x cheaper than petrol, and 30x cheaper than peak-rate grid charging. Over a typical 12,000 km/year of driving, the difference between solar-charged and petrol is $1,700–$2,200/year.
Sizing solar + battery for an EV
The right system size depends on driving distance:
| Daily driving | Extra solar needed | Battery sizing impact |
|---|---|---|
| 20–30 km | +1.5 kW | No change |
| 40–60 km | +2.5 kW | +3–4 kWh if overnight charging |
| 70–100 km | +4 kW | +5–7 kWh if overnight charging |
| 100+ km (regional commute) | +5 kW or workplace charging | +10 kWh or 2nd Powerwall |
For a typical Perth EV household driving 40–60 km/day, the recommended system is 10 kW solar + 13.5 kWh battery. This covers EV charging, evening AC, and provides whole-home backup.
Best EV chargers for Perth solar homes (2026)
- Tesla Wall Connector (7.4 kW single-phase or 22 kW three-phase): best for Tesla owners. Integrates with Tesla app for solar-only charging modes. $700 unit, $700–$1,200 install.
- Wallbox Pulsar Plus (7.4 kW or 22 kW): most popular non-Tesla charger. Solar-aware via the Wallbox app. Excellent ROI for households mixing brands. $1,200 unit, $700–$1,200 install.
- Zappi (7 kW or 22 kW): built specifically for solar diversion — only charges from solar surplus by default. Most “solar-pure” option. $1,400 unit, $700–$1,200 install.
- Schneider Electric EVlink (7.4 kW): enterprise-grade, OCPP-compatible. $1,500 unit, $800–$1,300 install.
Charging strategies for Perth EV + solar owners
Strategy 1: Solar-only charging (zero cost)
Set the EV charger to “eco” or “solar” mode. The charger only draws when there’s solar surplus above household consumption. Best for home-based people who can leave the car plugged in during the day. Pure solar-only charging adds 30–60 km of range per day in summer.
Strategy 2: Solar + battery + off-peak top-up
Default for households where the car returns home in the evening. Solar charges battery during day; battery covers evening household load and partial EV charge; remaining EV charging happens off-peak overnight at 9.5c/kWh. Effective $/100km: $1.40–$2.00.
Strategy 3: Off-peak only (no solar charge needed)
Simplest: charge the EV between 9pm and 7am on Smart Home Plan off-peak rate. No solar required — though solar still covers the rest of the household. $/100km: $1.70–$2.30. Useful if EV usage pattern doesn’t fit daytime charging.
Total cost of EV + solar + battery in Perth (2026)
- 10 kW solar: $7,800–$9,500
- 13.5 kWh Tesla Powerwall 3: $8,700–$10,400 (after rebates)
- 7 kW EV charger (Wallbox or Tesla Wall Connector) installed: $2,000–$2,900
- Switchboard upgrade if required: $800–$1,500
- Turnkey total: $19,500–$22,800
ROI: solar + battery + EV vs petrol car + grid electricity
- Petrol car fuel cost (12,000 km/year): ~$2,400
- EV grid charging cost (off-peak only): ~$240
- EV solar charging cost: ~$0
- Annual fuel saving with solar EV: $2,160–$2,400
- Annual household electricity saving from solar+battery: $3,800–$4,500
- Total annual saving: $5,960–$6,900
- Payback on $21,000 turnkey system: 3.0–3.5 years
Frequently asked questions
How much does it cost to charge an EV in Perth with solar?
Solar-only charging is effectively free (using your own solar surplus). Mixed solar + off-peak grid charging costs $1.20–$1.80 per 100 km — about 10x cheaper than petrol and 30x cheaper than peak-rate grid charging.
What’s the best EV charger for solar homes in Perth?
For Tesla owners, the Tesla Wall Connector. For everyone else, the Wallbox Pulsar Plus (most popular) or the Zappi (most “solar-pure”). All three integrate with major solar systems and support solar-only or off-peak charging modes.
Do I need a 22 kW three-phase EV charger?
Only if your home is three-phase and you’re driving 100+ km daily. For most Perth single-phase homes with 40–60 km/day commute, a 7 kW charger fully tops up the EV overnight. 22 kW is overkill and costs more to install.
Should I switch to Smart Home Plan after getting an EV?
Yes, almost always. Smart Home Plan’s 9.5c overnight off-peak rate is roughly a third of A1’s flat rate, and EVs charging overnight save 60–70% on charging costs. Combine with solar + battery and savings increase further.
Can I charge two EVs with one solar system?
Yes. Two EVs in a Perth household typically need 16–20 kWh/day of charging combined. A 13.2 kW solar + 13.5 kWh battery system can comfortably cover this plus household consumption, especially if both cars can charge during daytime hours. Two-charger setups with load-balancing keep total draw within the home’s supply limits.
Got an EV or planning one? Talk Energy installs solar + battery + EV-ready Perth setups in one project — in-house electricians, all rebates applied. Get a free Perth quote or call (08) 9468 1212.
