If you have already got solar panels or you are thinking about getting them, adding an electric vehicle to the mix is where things get really interesting.
Think about it: instead of paying $80+ to fill a petrol tank, or 35-50 cents per kWh to charge from the grid during peak times, you could be driving on electricity that cost you essentially nothing to generate.
The average Australian drives around 15,000 km per year. For a typical EV, that is roughly $600-800 worth of grid electricity annually, or $2,500+ in petrol for an equivalent petrol car. With solar charging? Your fuel cost drops close to zero.
Let us break down exactly how to make this work.
How much solar do you actually need for an EV?
This is the first question everyone asks, and the answer is more manageable than you might think.
The average Australian drives about 40km per day. Most modern EVs consume around 15-20 kWh per 100km, which means your daily driving needs roughly 6-8 kWh of electricity.
To generate that much power on an average day, you need approximately 1.5-2 kW of additional solar capacity on top of what you are already using for the house. In practical terms, that is 4-5 extra panels.
But here is the thing: most people do not charge their EV every single day. If you are commuting 40km daily, you might only need to charge 3-4 times per week. On sunny weekends when the car is parked at home, you can top up the battery from surplus solar while using minimal household power.
Quick sizing guide
If you are already exporting excess solar to the grid, you might not need any extra panels at all. That exported power could be going into your car instead.
Smart charging: Making the most of your solar
The key to maximising free EV charging is timing. You want your car to charge when solar production exceeds household consumption - typically late morning through mid-afternoon.
There are several ways to achieve this, from simple to sophisticated.
Timer-based charging
The simplest approach. Most EVs and chargers let you set charging schedules. Program yours to charge between 10am-3pm when solar production is highest. Free on all EVs, no special equipment needed.
Excess solar diversion
Smart chargers like the Zappi can automatically adjust charging speed to match your excess solar production. If you are generating 3kW of surplus, it charges at 3kW. Cloudy period? It pauses or slows down. This ensures you only charge with solar, never drawing from the grid.
Home energy management systems
Systems from Tesla, Sigenergy, and others can coordinate your solar, battery, EV charger, and home loads automatically. They optimise everything together: charging your car when solar is abundant, storing excess in your home battery for evening use, and only using grid power as a last resort.
Real-world tip
Even without smart equipment, you can manually start charging when you see your solar app showing strong export. Many EV owners get into the habit of checking their solar production after arriving home and plugging in accordingly.
Best EV chargers for solar integration
Not all EV chargers are created equal when it comes to working with solar. Here are the standout options for Australian homes.
Zappi (by Myenergi)
Best for solar diversion
The Zappi is purpose-built for solar homes. It monitors your energy flows in real-time and adjusts charging to match excess solar production. Three modes: Eco (solar only), Eco+ (minimum charge rate from grid, rest from solar), and Fast (full speed regardless of solar).
Tesla Wall Connector
Best for Tesla owners
If you have Tesla solar and Powerwall, the Wall Connector integrates beautifully through the Tesla app. It can coordinate with your home battery to maximise solar charging. For non-Tesla solar, it still offers scheduled charging and good build quality at a competitive price.
Fronius Wattpilot
Best for Fronius solar owners
If you have a Fronius inverter, the Wattpilot offers seamless integration through the Fronius Solar.web platform. It automatically detects excess solar and adjusts charging accordingly. PV surplus mode ensures your car only charges on solar.
Sigenergy EV Charger
Best all-in-one solution
If you are installing a full Sigenergy system (inverter + battery), their EV charger integrates natively. The whole system works together, automatically managing solar, battery storage, and EV charging for optimal efficiency. One app controls everything.
Do not have the budget for a smart charger? A basic 7kW charger with timer functionality (around $800-1,200 installed) still works well. Set it to charge during peak solar hours and you will capture most of the benefit.
Cost savings: Solar vs grid vs petrol
Let us do the maths on what you are actually saving.
Annual running costs: 15,000km per year
Petrol car (8L/100km @ $1.95/L)
Average fuel consumption for medium car
EV on grid peak (40c/kWh)
Charging in evening peak periods
EV on grid off-peak (15c/kWh)
Night charging on time-of-use tariff
EV on solar (effectively free)
Charging from excess solar production
Even comparing to off-peak grid charging, solar saves you $300+ per year. Compared to petrol, you are saving over $2,300 annually. That is nearly $200 a month back in your pocket.
Over the typical 10-15 year ownership of an EV, solar charging saves you $25,000-35,000 compared to a petrol equivalent. Not a bad return on a solar system that might cost $8,000-12,000.
The battery + EV combo: Charging overnight on stored solar
Here is where it gets really interesting. What if your car is not home during the day when the sun is shining?
If you have got a home battery, you can charge it during the day with excess solar, then use that stored energy to charge your EV when you get home in the evening.
It is not quite as efficient as direct solar-to-EV charging (you lose a bit in the battery charge/discharge cycle), but it is still way cheaper than grid power and gives you the flexibility to charge whenever suits you.
Sizing your battery for EV charging
If you want to charge your EV from your home battery overnight, size your battery to handle both household evening use AND EV charging. A typical evening might need 8-10 kWh for the house, plus 5-8 kWh for the car. A 15-20 kWh battery gives you comfortable headroom.
Some newer systems take this even further with "vehicle-to-home" (V2H) capability, where your EV can actually power your house during blackouts or peak periods. Your car becomes a giant mobile battery. The BYD Atto 3, Hyundai Ioniq 5, and Kia EV6 all support this with the right equipment.
Getting started: Your action plan
Whether you have already got solar or you are starting fresh, here is how to approach the solar + EV setup.
Assess your current solar production
Check your monitoring app. Are you exporting excess solar during the day? That export could be going into your car instead.
Calculate your EV charging needs
Estimate your daily driving and convert to kWh. For most people, this is 5-10 kWh per day.
Decide on a charging strategy
Will your car be home during solar hours? If yes, direct solar charging works great. If not, consider a battery or smart off-peak charging.
Choose an appropriate EV charger
Match the charger to your needs and budget. Basic charger with timer, or smart charger with solar diversion?
Consider system upgrades if needed
If you need more solar capacity or want to add a battery, get quotes that include EV charger installation. Bundle deals often save money.
The future is solar-powered transport
Combining solar with an EV is not just about saving money (though the savings are substantial). It is about energy independence - generating your own fuel from your own roof, insulated from both petrol price spikes and electricity rate increases.
The technology is mature, the economics work, and the installers know how to set it up properly. The only question is whether you are ready to stop paying for fuel.
If you are not sure where to start, take our rebate eligibility quiz to see what incentives you qualify for on solar, batteries, and EV chargers. Then get matched with local installers who can design a system tailored to your needs.
Passionate about making solar simple and accessible for every Australian household.