Updated on May 20, 2026
Are you considering adding an electric vehicle to your home and wondering if your current solar setup can keep up?
Many people run into the same issue. They already have solar panels or plan to install them, and they either own an EV or have one on the way.
An EV can use as much electricity as the rest of your home, so you may need to rethink your solar system size.
At PSC Energy, we’ve helped hundreds of customers across NSW and beyond with solar and EV setups. Our staff even charge their vehicles for free using our own solar system. We’ve gathered all the numbers and put them into a free guide you can download at the end of this article.
Here’s what this article covers:
- How Much Energy Does an EV Use?
- How Much Does It Cost to Charge an EV?
- How to Size Your Solar System to Charge an EV
- What If You Charge Your EV at Night?
- Real Example: Charging Two EVs from Solar in Kurmond, NSW
- How Workplace Charging Can Reduce Your Home System Requirements
- Free Download: EV Charging and Solar Sizing Guide
- FAQ: How Much Solar Do You Need to Charge an EV in Australia?
By the end of this article, you’ll know how much solar you need for your EV, whether you need batteries, and what a real household setup looks like.
How Much Energy Does an EV Use?
Before working out how much solar you need for your EV, it helps to know how much energy your car uses. Let’s look at a real example.
For example, the Tesla Model S Performance has a 100kWh battery and can travel about 500km on a full charge in real-world conditions. While the brochure says 600km, most people get closer to 500km in everyday driving. That means it uses about 20kWh per 100km.
This number is your main planning tool. It can change depending on how you drive:
- Drive 50km a day? You’ll need about 10kWh.
- Drive 100km a day? You’ll need about 20kWh.
- Drive 150km a day? You’ll need about 30kWh.
Most modern EVs in Australia use between 15 and 25kWh per 100km, depending on their size, weight, and how you drive.
Using 20kWh as an average is a safe bet for planning. You can check your car’s specs or use our free guide at the end of this article for details on different models.
How Much Does It Cost to Charge an EV?
If you charge your EV from the grid at the standard electricity rate (about $0.40 per kWh in 2026), a full 100kWh charge costs around $40. That’s enough for about 500km of driving.
For comparison, a typical family car uses about 10 litres of petrol per 100km. At $2.00 per litre, driving 500km costs about $100. Even at full electricity prices, running an EV is less than half the cost.
Now consider solar:
- Solar energy from your own roof costs you nothing at the point of use.
- Charging from solar can reduce your EV running cost to near zero.
- Any energy you store in a battery and use at night also avoids retail grid rates.
How much you save depends on how well your solar production lines up with your charging times. We’ll explain this in the next two sections.
If you’re interested in learning a bit more about public charging stations, you might want to check out the following article titled, Electric Vehicle (EV) Charging Guide 2026.
How to Size Your Solar System to Charge an EV
To work out how much solar you need for home EV charging, calculate your home’s energy use and your EV’s energy needs separately, then add them together.
Step 1: Calculate your home’s daily energy use.
Most Australian homes use between 15 and 25kWh of electricity each day. An 11.5kW solar system is a common starting size for this level of use.
Step 2: Calculate your EV’s daily energy needs.
Using the 20kWh per 100km rule, figure out how much energy your car uses on a typical day.
Step 3: Add them together and size accordingly.
- A 20kW solar system in Australia makes about 78kWh per day, based on an average of 3.9 peak sun hours, which is typical for Sydney and nearby areas.
- That gives you enough to power your home and deliver 20kWh or more to your EV every day.
- If your current solar system is enough for your home but not your car, you’ll usually need to add 5 to 6kW of extra solar panels for the EV.
Here’s a quick reference:
- Home only (no EV): 6.6 to 13kW system, depending on usage.
- Home plus one EV (moderate daily driving): 16 to 20kW system.
- Home plus two EVs: 25 to 30kW system.
This setup works best if you charge your EV during the day when your solar panels are making power. If you charge at night, things change.
What If You Charge Your EV at Night?
Most people drive to work and get home after sunset. If that’s your routine, you can’t charge your EV directly from solar unless you store the energy first.
To charge your EV at night using solar, you need battery storage. Here’s how the maths works:
- If you need 20kWh to top up your EV overnight, you need at least 20kWh of battery capacity reserved for that purpose.
- If you also want your home to run on stored solar at night, you need additional capacity on top of that.
A practical solution for a household charging one EV overnight looks like this:
- Two Tesla Powerwall 3 units deliver a combined 27kWh of usable storage.
- That gives you room to charge the EV and power the home through the night.
- You avoid expensive peak grid rates, and your home runs on solar around the clock.
The main downside is cost. Two Powerwalls are a big investment, and they only make sense if using solar overnight is important to you.
For many households, charging during the day with a bigger solar system is more affordable than buying a large battery setup.
If you’re interested in learning more about EV chargers, you might want to check out this guide titled, The 10 Best Home EV Chargers in Australia.
Real Example: Charging Two EVs from Solar in Kurmond, NSW
A homeowner in Kurmond, NSW, had a 30kW solar system and two Tesla Powerwalls. His daily commute was about 25km each way, so he didn’t need to top up the car during the week. Instead, he charged both EVs on weekends.
Here’s exactly how he managed it:
- He set the EV charger to start at 8:00am and run through the day.
- He reduced the charge rate to 10kW so the solar could simultaneously run the house and fill the Powerwalls.
- He avoided drawing from the grid and kept battery cycling low to extend battery life.
- He added about 60kWh to the car in a single day.
When a second EV joined the household, the routine changed. They charged one car on Saturday and the other on Sunday. They managed both solar production and battery storage carefully over the weekend.
This example shows a few key things for homes with more than one EV:
- Two EVs don’t just double your energy needs. They also require more flexibility in your charging schedule.
- A 25-30kW solar system is typically the minimum for a two-EV home that wants to charge primarily from solar.
- Multiple batteries provide a buffer to manage overnight charging and avoid grid dependence.
- Weekend charging routines can reduce the pressure on daily solar production.
The Kurmond setup worked because the homeowner had enough solar for both cars, a large battery for overnight charging, and a flexible schedule to spread charging over two days.
How Workplace Charging Can Reduce Your Home System Requirements
If you can charge your EV at work during the day, you’ll need less solar and battery storage at home. It’s a good idea to factor this into your planning.
Some employers are already installing EV charging for staff:
- Westmead Children’s Hospital has installed 75 EV chargers for staff to use during work hours.
- PSC Energy allows staff to charge their EVs for free using the company’s solar-powered system.
Charging 10 to 20kWh at work each day can really change what you need at home. If your workplace covers most of your weekday driving, you might be able to:
- Use a smaller solar system at home (closer to 13-16kW rather than 20kW).
- Reduce or eliminate battery storage, since you’re topping up during the day at work.
- Lower your overall energy costs further, since workplace solar charging is often free.
This option isn’t available to everyone. But if you do have access to workplace charging, make sure to include it in your planning before sizing your home system. It could save you a lot of money up front.
If you’re wondering if you EV supports bidirectional charging, you might want to check out the following article titled, What EVs Support Bidirectional Charging in Australia?
Free Download: EV Charging and Solar Sizing Guide
To make things easier, PSC Energy has put together a free PDF guide. We created it after helping dozens of customers with these sizing calculations.
The guide includes:
- How much solar and battery storage you’ll need based on your specific driving habits.
- The top 20 EV models currently available in Australia.
- Real-world range figures for each model (not brochure estimates).
- How much energy each car needs per charge, and how long it takes to charge.
Wrapping Up: Don’t Get Left on Empty
Pairing an EV with solar is one of the best energy choices you can make as an Australian homeowner. But it only works well if your system is set up correctly.
PSC Energy has helped hundreds of households get their solar and EV charging systems sized just right. We base our quotes on your real usage, roof, and driving habits, not a one-size-fits-all package.
If you want to get your numbers right, reach out to our team or download the free EV charging and solar sizing guide.
If you’re interested in learning a bit more about charging your EV from solar, you might want to check out the following article titled, Considerations for Charging Your Electric Vehicles with Solar.
FAQ: How Much Solar Do You Need to Charge an EV in Australia?
How much solar do I need to charge an EV at home in Australia?
Most households charging one EV during the day need between 16 and 20kW of solar. This covers average home usage (around 15-25kWh per day) plus the EV’s daily energy needs. If you already have a system sized for the home, expect to add 5-6kW to account for the car.
How many kWh does an EV use per 100km?
Most modern EVs use between 15 and 25kWh per 100km in real-world conditions. A useful planning figure is 20kWh per 100km. Multiply that by your daily driving distance to get your daily energy requirement.
Can I charge my EV with solar panels during the day?
Yes. Daytime charging is the most efficient way to use solar for your EV. Your solar system generates power when the sun is up, and your EV charger uses that power directly. No battery storage required for day charging.
Do I need a battery to charge my EV with solar power?
Not if you charge during the day. But if you charge at night or want your home to run on solar after dark, you’ll need battery storage. Plan for at least 20kWh of battery capacity for the EV alone, plus extra capacity for the home.
How much does it cost to charge an EV from solar vs the grid?
At grid rates of around $0.40 per kWh, a full 100kWh charge costs about $40. Charging from solar reduces that cost to near zero, since you’re using energy your system generates rather than buying it from the retailer.
What size solar system do I need for two EVs?
A two-EV household that wants to charge primarily from solar typically needs a 25-30kW system. You’ll also benefit from multiple batteries if either car charges at night. Weekend charging routines can help you manage a smaller system more efficiently.
Can I add an EV to my existing solar system, or do I need a new one?
You can add to an existing system in most cases. If your current system is 11 to 13kW, adding 5 to 6kW of extra panels is usually enough to cover a single EV. A full redesign is only necessary if your roof space or inverter capacity can’t accommodate the additional panels.
How does workplace EV charging affect the amount of solar I need at home?
Significantly. If you charge 10 to 20kWh at work each weekday, you reduce the load on your home system by that amount. Some households with access to free workplace solar charging can get by with a 13-16kW home system and little or no battery storage.
