Going off-grid with an EV: cost, size and payback
Going off-grid means your panels, battery and usually a backup generator supply all your power, including charging an EV. For an average home with an EV it typically costs $40,000–$70,000, about two to five times a grid-connected solar and battery system. It makes the most financial sense where connecting to the grid would cost tens of thousands of dollars, such as a new rural build. For a home that's already connected, staying on the grid with solar and a battery is usually far cheaper. Use the calculator to size a system yourself, or enter the sizes you've been quoted.
Off-grid calculator: size, cost and payback
Estimates only. Real costs depend on your site, roof, access and installer, and off-grid systems must be designed by an accredited designer. Weather varies year to year. Use this to understand the size and budget, then get at least two quotes.
Off-grid or stay connected?
| Off-grid | Grid-connected solar + battery | |
|---|---|---|
| Typical cost (3–4 bed home) | $40,000–$70,000 | $12,000–$20,000 |
| Power bills | None, but generator fuel in winter | Small; supply charge still applies |
| Selling excess solar | Not possible | Feed-in credits |
| Long cloudy spells | Battery, then generator | The grid covers it |
| Best for | Remote blocks and new builds far from the grid | Almost everyone already connected |
If you're already on the grid, see solar and battery payback and free midday power first: they're usually the cheaper route to low bills.
How many panels do you need?
Off-grid panels are sized for winter, not the average day, because that's when you get least sun and often use most power. In June, panels produce roughly half to three-quarters of their yearly average in most capitals.
| Capital | Per kW of panels, average day | Per kW, June day | June vs average |
|---|---|---|---|
| NSW | 4.0 kWh | 2.8 kWh | 71% |
| Victoria | 3.6 kWh | 2.1 kWh | 57% |
| Queensland | 4.2 kWh | 3.2 kWh | 75% |
| South Australia | 4.2 kWh | 2.4 kWh | 57% |
| WA | 4.4 kWh | 2.9 kWh | 66% |
| Tasmania | 3.5 kWh | 1.7 kWh | 49% |
| ACT | 4.3 kWh | 2.6 kWh | 60% |
| NT | 4.4 kWh | 4.9 kWh | 112% |
Rule of thumb: daily use ÷ June output per kW. A home using 16 kWh a day in Sydney needs about 6 kW for winter, about 14 panels of 440 W. The calculator sizes the house for winter but the car for an average day, because in the darkest weeks most owners top the car up at a public charger or run it lower rather than buy a much bigger array.
How big a battery?
The battery has to carry the house through the night and through cloudy days. Installers talk about days of autonomy: most off-grid homes plan for one to three. Two days of a 16 kWh-a-day home is about 36 kWh of usable storage. With a generator you can go smaller; without one, plan for three days or more.
Charge the EV in the middle of the day straight from the panels rather than from the battery. A car battery holds far more than a house battery, and charging it overnight would empty the house battery quickly.
Running an EV off-grid
- Charge in daylight. Set the car or charger to charge between about 10am and 3pm, or use a solar-aware charger that only uses surplus solar.
- Size the inverter for the charger. A 7 kW charger plus the house needs a large off-grid inverter. Many owners charge at a lower rate (2–3.5 kW) to stay within the inverter and solar output.
- Plan for winter. Keep the car topped up on sunny days and use public fast chargers on long runs.
- Vehicle-to-home (V2H). A few EVs can power the house from the car battery with the right bidirectional charger. It's still early and needs approval, so check your car and installer.
What it costs and what helps
- Panels: about $1,100 per kW installed after the federal STC rebate (grid-connected systems run about $800–1,200 per kW).
- Battery: the biggest cost, 40–50% of the total. About $850 per kWh installed after the federal battery discount. The discount is full for the first 14 kWh, reduced up to 28 kWh and small up to 50 kWh, with nothing beyond that. Eligible off-grid homes can claim it for one battery.
- Off-grid inverter, switchboard and installation: about $11,000, more on remote or difficult sites.
- Generator: about $4,000, plus fuel in winter.
- Lifespans: panels 25–30 years, batteries and inverters 10–15 years. Budget for one battery and inverter replacement over 20 years; our 20-year figure includes this.
- Design and approval: off-grid systems must be designed and installed by accredited professionals. Ask about council requirements and insurance.
Common questions
How much does it cost to go off-grid in Australia?
For a typical 3–4 bedroom home, about $40,000–$70,000 installed for 8–12 kW of panels, a 30–40 kWh battery, an off-grid inverter and a backup generator. A small cabin can be $15,000–$30,000, and a large high-use home $70,000–$120,000 or more.
How many solar panels do I need to go off-grid?
Divide your daily use by the June output per kW where you live. For 16 kWh a day in Sydney that's about 6 kW, roughly 14 panels of 440 W. Add more if you charge an EV at home.
Can I charge an electric car off-grid?
Yes. Charge it during the day from the panels rather than from the house battery. In winter you may need to top up at public chargers or with the generator.
Is going off-grid worth it if I'm already connected?
Usually not financially. A grid-connected solar and battery system costs a fraction as much and the grid backs you up. Off-grid pays off mainly where a new grid connection would be very expensive.
Do I still get rebates if I go off-grid?
Yes. Eligible off-grid systems can earn small-scale technology certificates (STCs) for the panels, and the federal battery discount for one battery per off-grid home.
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How we work it out, and our sources
Weekly cost = the car's energy use × 250 km × your electricity or fuel price, with 90% of charging at home. Prices are list prices at October 2026; check with the dealer.
- Electricity: 2026–27 default rates (AER, Victorian Default Offer, state retailers). Public charging: Sydney network prices, July 2026.
- Petrol and diesel: ACCC capital-city averages, 21 October 2026.
- Cars: maker figures via CarExpert, Drive, CarsGuide and EV Central. Plug-in electric range is taken as 80% of the claim.
- Servicing: published capped prices; marked as an estimate where not yet published (CarExpert comparison).
- Tyres: an EV set lasts about 35,000 km, a petrol or hybrid set 50,000 km (RACV); prices from Gridly.
- Home charger: about $2,000 installed ($1,000–$3,000). Novated leases: PwC summary.
Printed from EV Pick · evpick.com.au. Prices and costs are estimates; check with the dealer. © 2026 EV Pick (T. Crouch). For personal use only; not to be copied, republished or sold without permission.