Solar panels + EV charging: the ultimate Aussie savings combo

Solar panels save money on your electricity bill. An EV saves money on fuel. Put them together and the savings compound — you are essentially driving on sunlight, and your per-kilometre cost drops close to zero.

Australia has some of the highest rooftop solar adoption in the world. Over 3.6 million homes already have panels installed. If you are one of them and you drive an EV, you are sitting on a combination that most countries cannot match.

How the maths works

A typical 6.6 kW solar system in Sydney generates about 24 kWh per day. An average EV needs about 5.5 kWh to cover 37 kilometres — roughly a typical daily commute. That means your solar system generates more than enough energy to charge your car and still power most of your home.

Without solar, home charging at 33 cents per kWh costs about $660 per year for 13,300 km of driving. With solar, that same energy comes from your roof at an effective cost of 5 to 8 cents per kWh (the opportunity cost of the feed-in tariff you would have earned by exporting it). Your annual charging cost drops to $100 to $160.

That is a saving of $500 to $560 per year on charging alone, stacked on top of the $1,300 to $2,300 you already save by driving electric instead of petrol.

Timing your charge matters

The biggest win comes from charging during the day when your panels are producing. Most EVs let you schedule charging. Set your car to charge between 10 am and 3 pm and you are using free solar energy instead of drawing from the grid at night.

If you cannot charge during the day — say you drive to work and your car is not home — the next best option is off-peak overnight charging. Many energy retailers offer time-of-use plans with off-peak rates between 15 and 22 cents per kWh, roughly half the standard rate. Your annual charging cost on off-peak sits around $300 to $400.

Feed-in tariffs and the export equation

Feed-in tariffs in Australia range from 3 to 12 cents per kWh depending on your state and retailer. Every kWh you use to charge your car instead of exporting saves you the difference between your import rate (33 cents) and your feed-in rate (say 5 cents). That is 28 cents of value per kWh kept in your home.

In practical terms: using your own solar to charge your EV is worth 5 to 6 times more than exporting that same energy to the grid. The maths strongly favours self-consumption.

Payback period for the combined setup

A 6.6 kW solar system costs $4,000 to $7,000 after rebates. A Level 2 home EV charger adds $1,000 to $2,000 installed. Total investment: $5,000 to $9,000.

Combined annual savings from solar (electricity bill reduction) plus EV charging (versus petrol) typically land between $2,800 and $4,200 per year. That puts the payback period for the entire solar + charger setup at 2 to 3 years. After that, you are effectively driving for free.

Helira's Solar Hub calculates the payback period for your specific situation — your postcode, your system size, your electricity rate, and your driving distance. The charge timing tool shows you the optimal hours to charge based on your energy plan.

Solar and EV together is not a future idea. It is a present-day financial decision that pays for itself within a few years. If you already have panels, the only question is which EV to buy. If you already have an EV, the only question is how fast you can get panels on your roof.