Picture this: it’s a bright summer morning in Brisbane, and you’re about to head off on your weekend getaway to the Sunshine Coast. You hop into your electric car—no last-minute fuel stop required—and as you glide out of the driveway, you can’t help but smile knowing your home solar panels did all the heavy lifting overnight. In a country blessed with endless sun, powering your EV straight from the rooftop is not only possible, it’s downright smart.
By pairing a home solar system with an electric vehicle charger, Australians can tap into free, clean energy and watch their electricity bills shrink—sometimes to near zero. Whether you’re charging up for the morning school run in Melbourne or gearing up for a coastal road trip in Perth, every kilowatt you generate yourself is a dollar saved.
Can I Charge an EV with My Solar Panels?
Imagine cruising around Sydney or Melbourne knowing every kilometre you drive was powered by the Queensland sun on your roof. Thanks to today’s home solar systems and smart EV chargers, you can plug your car straight into the clean energy you generate yourself. It’s as simple as letting your rooftop panels soak up daylight, then using that free, renewable power to fill your battery—saving you money and cutting emissions, all at once.
Understanding Your Solar System’s Capacity
Before you plug in, it pays to know exactly how much juice your rooftop can deliver—and what that means for charging your EV.
- System Size (kW): This number on your inverter (e.g. 6 kW) is the maximum power your panels can make under perfect sun—think of it as your roof’s peak output.
- Peak Sun Hours: Most Aussie homes get 4–5 “full sun” hours a day (Darwin/Brisbane nearly 5 h, Melbourne/Hobart closer to 3.5 h). Multiply your system size by those hours to estimate daily energy. Example: 6 kW × 4 h = 24 kWh/day.
- Inverter Limitations: If your inverter is rated lower than your panel array (say 5 kW on a 6 kW system), your peak will be capped at 5 kW—but you’ll still harvest all the extra energy across the day.
- Orientation & Tilt: North-facing panels tilted about 20–30° yield the best year-round results in Australia. East-/west-facing roofs work, but expect 10–20% less midday output.
Timing and Smart Charging
Timing your charging right and using a smart charger can turn your rooftop sunshine into extra savings.
Daytime Charging
- Best Hours: Plug in between 10 am and 2 pm when your panels are making the most power.
- Beat the Grid: Charging after dark means using grid electricity, which costs more.
- Two-Part Top-Up: If you don’t need a full charge every day, do a long midday charge and a quick after-work boost—most of your energy still comes from the sun.
Smart Charging Systems
- Use Solar First: Chargers with “solar-first” mode only draw what your panels produce and pause when the sun dips.
- Set a Schedule: Tell your charger to start at midday—no fiddling needed.
- Balance Your Home Load: If your oven or air conditioner turns on, a smart charger will slow down to keep your main fuse happy.
- Control from Your Phone: Check charging progress, switch modes, or get alerts if clouds roll in.
Financial and Environmental Benefits
Pairing your home solar system with an EV charger doesn’t just help your wallet—it’s a win for the planet, too. Here’s how tapping into rooftop sunshine delivers real financial and environmental wins for Aussie households.
Cost Savings
- Lower Power Bills: Charging your EV with solar means you’re using energy you’ve already generated—some days you’ll even have extra to sell back to the grid.
- Big Fuel Savings: At around $2–$3 of solar power per 100 km versus $15–$20 in petrol, you’ll see the difference each time you drive.
- Upfront Discounts: Government rebates and Small-scale Technology Certificates can shave thousands off your solar system cost.
- Long-Term Wins: Solar panels last 25 + years, and EVs need less servicing than petrol cars. Many homeowners cover their solar investment in under 7 years.
Reduced Carbon Footprint
- Zero Tailpipe Emissions: Every kilometre you drive on solar is free of CO₂—no more petrol fumes in your garage.
- Cleaner Neighbourhood Grid: Extra solar power you don’t use goes back to the grid, cutting out coal- and gas burning at peak times.
- Yearly CO₂ Savings: A typical Aussie solar setup can stop 4–6 tonnes of CO₂ a year—add EV charging and you could slash another 2–3 tonnes by avoiding petrol.
- Backing Renewables: The more you charge on your own sunpower, the more you support a greener energy future for everyone.
How Much Solar Do You Need to Charge an EV?
Imagine pulling into your driveway and plugging in your electric car, confident that your roof is ready to deliver enough sunshine to get you where you need to go. But how many solar panels does that actually take? Whether you’re commuting around Perth or heading out for a weekend in Byron Bay, knowing the right system size helps you avoid under- or over-investing. Let’s break down the simple math behind matching your daily driving needs to the perfect Aussie solar setup.
Understanding Your EV's Energy Consumption
Every EV lists its efficiency in kilowatt-hours per 100 km (kWh/100 km)—think of it like litres per 100 km for petrol cars. To work out how much solar you need, start by estimating your daily kWh demand:
Efficiency Rating
- Small city cars (e.g. Nissan Leaf): ~15 kWh/100 km
- Sedans & crossovers (e.g. Tesla Model 3): ~18–20 kWh/100 km
- Large SUVs & utes (e.g. Mustang Mach-E): ~22–25 kWh/100 km
Daily Distance
- Multiply your round-trip kilometres by the rating, then divide by 100.
- Example: 40 km × 17 kWh/100 km ÷ 100 = 6.8 kWh
Adjust for Real-World Factors
- Charging Losses (≈10%): 6.8 kWh × 1.1 ≈ 7.5 kWh
- Climate Control: +1–2 kWh if you run air conditioner in summer or heater in winter
- Highway & Hills: +10–20% if you do long motorway stints or climb the Great Dividing Range
Putting it all together, your daily kWh need is roughly:
- (Distance × Efficiency ÷ 100) × 1.1 + any climate or terrain allowance
With a single, consolidated list, you have the full picture in one place—no more jumping between sections.
Determining Solar System Size
Sizing your solar system to keep your EV charged is really just matching two numbers: how much energy your car needs each day and how much your roof can produce. Here’s a step-by-step way to work it out for most Aussie homes:
Work Out Your Daily EV Energy Need
- Find your daily kWh from your commute (e.g., 40 km × 17 kWh/100 km ÷ 100 ≈ 6.8 kWh).
- Add ~10% for charging losses (6.8 kWh × 1.1 ≈ 7.5 kWh).
Know Your Local Sun Hours
- Darwin/Brisbane: ~5 hours
- Melbourne/Hobart: ~3.5 hours
- Each 1 kW of panels gives roughly “1 kW × sun hours” in kWh/day.
Calculate Panel Size
Divide your EV need by daily yield per kW:
Example (Melbourne): 7.5 kWh ÷ 3.5 kWh ≈ 2.1 kW of panels.
Add a Safety Margin
Multiply by 1.3 to cover cloudy days and home use:
2.1 kW × 1.3 ≈ 2.7 kW—round up to a standard 3 kW system.
Check Your Roof Space
3 kW needs about 15–20 m² of north-facing roof (tilt ~25°).
East/west roofs work too but may need a few extra panels.
Match Your Inverter & Charger
- Make sure your inverter can handle the panel size (e.g., ≥3 kW).
- Confirm your EV charger’s max power fits the inverter’s output.
Think About Batteries (Optional)
- A 10 kWh battery can store extra solar so you can charge after dark or during outages.
Average Solar Irradiance in Newcastle
Newcastle’s sunshine is perfect for solar-powered EV charging. Here’s the simple breakdown:
Daily Sunshine Average:
- About 4.75 kWh per m² each day. That means each 1 kW of panels makes roughly 4.75 kWh on a clear day.
Summer vs Winter:
- Summer (Dec–Feb): Around 5.5–6.0 kWh/m²/day – a 1 kW system can make up to 6 kWh.
- Winter (Jun–Aug): Drops to 3.5–4.0 kWh/m²/day – closer to 4 kWh per kW installed.
Peak Sun Hours:
- Think of it as 4.75 “full sun” hours daily—the rule of thumb used to size panels.
Best Panel Position:
- North-facing, tilted about 20–30° gets the most sun. East or west works too but makes 10–20% less midday power.
What This Means for Your EV
- A 3 kW system in Newcastle typically produces 14–18 kWh/day—enough for a 50–60 km drive (8–12 kWh) on sunny days.
- In winter, generate less, so aim to charge around clear midday hours or add a small battery to store extra for later.
Solar Panel Efficiency
Panel efficiency is the percentage of sunlight a solar panel turns into electricity. Higher efficiency means more power from the same roof space.
Common Efficiency Levels
- High (Monocrystalline): 18–23% – best when you have limited roof area.
- Mid (Polycrystalline): 15–18% – a bit cheaper, needs more space.
- Low (Thin-Film): 10–12% – flexible panels, but you need lots of them.
Why It Matters for Your Home
- Small Roof? High-efficiency panels squeeze more kW into less space.
- Big Roof? You can choose mid-range panels to save on upfront costs.
Everyday Factors That Affect Output
- Heat: Panels work best at 25 °C. Each degree hotter can cut output by 0.3–0.5%.
- Dirt & Shade: A dusty panel or a single shaded cell can drop your yield by up to 20%.
- Angle & Direction: North-facing panels tilted 20–30° get the most Aussie sun.
Picking the Right Panel
- Space-Constrained: Go for 20%+ efficiency panels.
- Room to Spare: 17–19% panels balance cost and performance.
- Long-Term Value: Look for panels that lose less than 0.5% efficiency each year.
Calculating the Number of Solar Panels
Find your daily kWh need
- From earlier, say you need 7.5 kWh every day (including charging losses).
Pick a panel size
- Most home panels are 370 W (0.37 kW).
Estimate what one panel makes
- Multiply 0.37 kW × your sun hours:
- e.g. in Adelaide: 0.37 kW × 4 h = 1.48 kWh per panel each day.
- Divide to get panel count
- 7.5 kWh ÷ 1.48 kWh ≈ 5 panels.
Add a safety margin
- Multiply by 1.25 (for cloudy days or extra home use):
- 5 × 1.25 = 6.25 → round up to 7 panels.
Check your roof space
- Seven panels need about 10–12 m² of north-facing roof.
System Losses and Battery Storage
Even the best solar setup has a few “leaks” before your car gets the power—and adding a battery helps you catch extras for later.
System Losses
- Inverter Conversion: Converting panel DC to home AC loses about 5–10%.
- Wiring: Long cables or loose connections cost another 1–3%.
- Charger & Battery: Your home charger and car battery add around 10% more loss—so 10 kWh from your panels might give only 9 kWh to the car.
- Dirt & Shade: Dust, leaves, or a shaded corner can cut panel output by 5–20%.
Battery Storage
- Save Extra Solar: A 10 kWh battery can store midday surplus instead of sending it to the grid.
- Charge Anytime: Use stored power to charge your EV at night or during cloudy spells.
- Backup Power: In a blackout, your battery keeps lights, fridge—and even an EV top-up—running.
- Steadier Output: Batteries smooth out dips on cloudy days so you rely less on the grid.
Timing Your EV Charging for Maximum Solar Benefit
There’s a real sweet spot for charging your EV when the Aussie sun is at its peak—usually between 10 am and 2 pm. Plugging in during these hours means you draw almost entirely on your own solar power, not the grid, so you cut your electricity costs and carbon emissions at the same time.
Understanding Solar Energy Production
Solar energy production is what makes your home solar-to-EV setup tick. Here’s the simple breakdown of how and when your panels make power in Australia:
How Panels Work
- Sunlight to Electricity: Light hits silicon cells, freeing electrons and creating a flow of DC power.
- Inverter Converts: The inverter turns that DC into the AC power your home and EV charger use.
When They Produce Most
- Midday Peak: Power is highest around solar noon—roughly 11 am to 1 pm.
- Roof Position: North-facing panels tilted about 20–30° soak up the most Aussie sun.
- Weather Impact: Clear skies = full output; clouds can cut production by 20–80%.
Seasonal Swings
- Summer: Longer days and a high sun angle give you up to 30% more energy.
- Winter: Shorter, lower-angle days mean you’ll get less—plan for smaller mid-year yields.
Sizing with Peak Sun Hours
- Peak Sun Hours: A handy rule translating all daylight into “full-sun” hours (e.g., 4.5 hours in Sydney).
- Daily Yield: System size (kW) × peak sun hours ≈ kWh you can expect each day.
Real-World Factors
- Heat Loss: Panels run best at 25 °C—expect about 0.3–0.5% efficiency drop per °C above that.
- Keep Them Clean: Dust, pollen, or bird droppings can shave off up to 15% of your output. A quick rinse every few months keeps production up.
Assessing Your Solar System Capacity
Before setting up a charging schedule, evaluate your solar system's capacity. Consider the size of your solar array and the average daily electricity generation. This assessment will help you determine how much of your EV's battery can be charged solely with solar energy and whether any adjustments, such as expanding your solar system or altering your EV's charging times, are necessary.
Scheduling Daytime Charging
Planning your EV charging to line up with midday sun makes sure most of your battery top-up comes straight from your panels. Here’s how to lock in those sunshine hours:
Set a Charging Timer
- Schedule your charger to run from 11 am to 2 pm—that’s when panels make the most power.
- Lock out evening or overnight charging so you don’t accidentally pull from the grid.
Watch Your Electricity Rates
- If your plan has midday off-peak prices, charge them to save even more.
- Avoid late-afternoon and evening peaks when rates jump up.
Use the Weather
- On cloudy days, aim for the brightest hour (often 12 pm–1 pm).
- Some smart chargers adjust automatically using weather forecasts.
Split Your Sessions
- Do a big charge at midday and a small top-up after work—most energy still comes from your panels.
Check & Tweak
- Look at your charger’s app: if you see grid power being used, shift the start or end time by 15–30 minutes.
Monitoring and Adjusting Your Charging Strategy
Keeping an eye on how and when you charge lets you squeeze every drop of sunshine into your EV and keeps grid use to a minimum. Here’s how to monitor your setup and tweak it for top efficiency:
Check Your Charger App
- See live data to spot any grid draw—if you notice it, make a note of when it happens.
- Most apps break down how many kWh came from solar vs. the grid.
Watch Your Solar Output
- Look at your inverter’s daily report to see how much power your panels made.
- If you spot cloudy or shaded days, plan fewer or shorter charges then.
Tweak Your Charge Times
- If you still see grid power at 2 pm, end charging at 1:30 pm instead.
- If panels peak at 11 am, start charging closer to 10:45 am.
Use Alerts & Automation
- Turn on notifications so you’re warned if mains power kicks in.
- Some chargers can pause automatically when solar output falls below a set level.
Review Your Savings
- Each month, compare kWh charged on solar vs. grid.
- Convert that into dollars and CO₂ saved to see your progress
Adjust for Seasons
- Shift your charging window by 30–60 minutes to match summer’s or winter’s sun peak.
- Remember to update timers when daylight saving starts or ends.
Using Smart EV Chargers to Optimise Solar Use
Smart EV chargers act like traffic controllers for your home energy, sending sunlight straight into your car battery and keeping grid power at bay. With the right charger in sunny Adelaide or overcast Hobart, you can automatically match your charging to peak solar output—so you’re tapping into free, clean energy every time you plug in.
Understanding Smart EV Chargers
Smart EV chargers are your home’s energy brain—automatically steering solar power into your car and keeping costly grid juice at arm’s length. Here’s how they work and what makes them a game-changer for Aussie homes:
Solar-First Charging
- Use your rooftop solar power first and only dips into the grid if panels can’t keep up.
- Automatically pauses when clouds roll in, then resumes when the sun’s back.
Easy Scheduling
- Pick a time slot (e.g., 10 am–2 pm) and the charger handles the rest—no daily fiddling.
- Some even shift charging to match cheaper off-peak rates.
Home Load Balancing
- Keep an eye on everything else you’re running (oven, air-con) and slows or pauses charging so you don’t trip breakers or hit peak tariffs.
App Control & Insights
- See in real time how much energy came from solar versus the grid.
- Start, stop, or tweak charging from your phone—anywhere, anytime.
Ready for Tomorrow
- Supports Vehicle-to-Home (V2H) and Vehicle-to-Grid (V2G), letting your car feed power back to your house or earn credits on the grid.
- Gets smarter over time with firmware updates—new features arrive automatically.
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Maximising Solar Utilisation
Before you dive into smart charging, it helps to know exactly how much solar power you have to play with—and what happens when you’ve got extra. Here’s how to assess your system’s capacity:
Solar Prioritisation
- Know Your Peak Output: Watch your inverter’s midday number—if it hits 5 kW at 1 pm, that’s the most your charger can use without tapping the grid.
- Enable Solar-First Mode: In your charger’s app, turn on “solar-first” so it only pulls what your panels make and stops when clouds roll in.
- Match Rates to Production: If your panels make 3 kW and your charger wants 7 kW, you’ll automatically draw the extra 4 kW from the grid—so stay within your sun-powered limit.
Surplus Solar Energy Use
- Store Extras: Send any unused solar into a home battery for evening EV charging or backup power.
- Power Your Home: Use surplus to run appliances (dishwasher, fridge, air-con) before exporting to the grid.
- Adjust Charging Speed: If you have more solar than your car needs (e.g., panels at 6 kW, charger at 3 kW), bump up the charger’s power setting to soak up the extra.
- Check Feed-In Value: If you don’t have a battery, compare your feed-in tariff to your daytime electricity cost—sometimes it’s worth shifting laundry or pool pumps into peak sun hours to use that free power.
Future-Proofing with Smart EV Chargers
Smart EV chargers aren’t just for today—they’re built to stay useful as technology and your needs change. Here’s why picking a future-ready charger makes sense:
Automatic Updates
- Gets new features and security fixes over the air—no hardware swap needed.
Easy to Expand
- Add another charger or boost power output when you get a faster EV or a second car.
Bidirectional Ready
- Lets your car send power back to your home (V2H) or the grid (V2G) when rates are high or during outages.
Works with Standards
- Uses open protocols (like OCPP) so it’ll play nice with new EVs, home-energy apps, and smart grids.
Cloud Monitoring
- View past charging data, cost savings, and energy reports from your phone or computer.
Future Integrations
- Ready to connect with new services—like real-time tariff programmes, weather-based charging, or grid-support markets.
Should You Add a Battery to Charge Your EV at Night?
Imagine pulling into your garage after a sun-soaked day, only to plug in your EV after the sun has set. Without a battery, you’ll tap the grid at night—when power prices and emissions can spike. But by adding a home battery, you can store daylight hours’ solar energy and use it to top up your car under the stars. Whether you’re in sunny Darwin or cooler Launceston, a battery can turn your rooftop into a round-the-clock charging station that saves you money and keeps your driving green.
The Role of Battery Storage
Battery storage acts like a daylight “fuel tank” for your home, holding onto extra solar energy so you can charge your EV long after the sun goes down. In Australia’s varying climate—from the tropical highs of Cairns to the cool evenings in Hobart—a battery ensures your rooftop panels keep working for you 24/7. Instead of switching to grid power at night (when prices and emissions often rise), you simply drain your stored sunshine, saving on bills and reducing your carbon footprint—all while keeping your EV ready to roll.
Benefits of Adding a Battery
1. Energy Independence and Reliability
- A battery storage system enhances your energy independence by reducing reliance on the grid. This is particularly beneficial during peak demand periods or grid outages.
- With a battery, you ensure a consistent power supply for charging your EV, regardless of solar production or grid availability.
2. Cost Savings
- By storing excess solar energy, you can significantly reduce or even eliminate the need to draw power from the grid during peak evening hours, when electricity rates are typically higher.
- Utilising stored solar energy for EV charging at night can lead to substantial savings on your overall energy bills.
3. Maximised Solar Utilisation
- Batteries allow you to maximise the use of your solar energy system by capturing and storing surplus energy that would otherwise be fed back into the grid, often at a lower feed-in tariff.
- This stored energy can then be used to charge your EV, improving the overall efficiency and return on investment of your solar installation.
Will EV Charging Increase My Power Bill?
Plugging in your EV certainly adds to your home’s electricity use—but with a bit of savvy timing and knowhow, you’ll barely notice the extra cost.
Understanding Energy Consumption
- Most Aussie EVs guzzle about 15–20 kWh to cover 100 km. So if your daily run is around 50 km, you’re looking at roughly 8–10 kWh each time you plug in. At an average rate of 30 ¢ per kWh, that works out to about three bucks per top-up (give or take the 10 % your charger and battery lose along the way).
Timing Is Everything
- Shift your charging to off-peak or midday solar hours, and you’ll save up to 30 % on every session. For example, overnight off-peak rates can be as low as 20 ¢, whereas evening peaks might jump to 40 ¢. Or better yet, if you zap your car between 10 am and 2 pm on sunny days, you’re effectively paying zero for those kilowatt-hours.
Your Driving Style Matters
- A gentle city commute with lots of stop-start traffic and regen braking can actually boost your range and lower your kWh/km. On the flip side, blasting along the highway at 110 km/h or towing a trailer up the Great Dividing Range can hike your energy use by 10–20 %. And don’t forget: full-blast air-con in Darwin’s summer or the heater in Hobart’s winter adds another 1–3 kWh per charge.
Benefits of Pairing Solar with EV Charging
Pairing solar energy with EV charging offers numerous advantages, making it an attractive proposition for homeowners looking to reduce their carbon footprint and electricity expenses.
1. Cost Savings
- Reduced Electricity Costs: By using solar energy to charge your EV, you can significantly reduce or even eliminate the cost of electricity from the grid for charging.
- Government Incentives: Various incentives, such as Small-scale Technology Certificates (STCs), can reduce the upfront cost of solar installation, enhancing the financial benefits.
2. Environmental Impact
- Sustainable Energy Source: Solar power is a clean, renewable energy source that significantly reduces greenhouse gas emissions compared to fossil fuels.
- Energy Independence: By generating your own electricity, you decrease reliance on grid power, contributing to a more sustainable energy ecosystem.
3. Increased Property Value
- Attractive to Buyers: Homes equipped with solar panels and EV charging infrastructure are becoming increasingly attractive to environmentally conscious buyers and can potentially increase property value.
- Future-Proofing: As EVs become more prevalent, having a home equipped for solar-powered EV charging positions you ahead of the curve.
4. Energy Efficiency and Management
- Smart Energy Solutions: Integrating solar with smart energy management systems allows for optimised energy use, ensuring that your solar power is used efficiently for home and vehicle needs.
- Battery Storage Options: Pairing solar with battery storage can further enhance efficiency, allowing you to store excess solar energy for use during non-sunny periods or peak demand times.
What to Consider Before You Install
Before proceeding with the installation of a solar-powered EV charging system, several key factors need careful consideration to ensure a seamless and beneficial transition.
1. System Size and Capacity
- Energy Needs Assessment: Evaluate your household's energy consumption and your EV's charging requirements to determine the appropriate size of the solar system.
- Future-Proofing: Consider potential future energy needs, such as additional EVs or increased household consumption, when selecting system capacity.
2. Installation Costs and Financing
- Budgeting and Planning: The initial cost of solar panel installation can be substantial, but various financing options, such as solar loans or leasing, can make it more manageable.
- Return on Investment: Calculate the potential savings on energy bills and available incentives to understand the return on your investment.
3. Regulations and Permits
- Local Requirements: Familiarise yourself with local regulations and requirements for solar installations in Newcastle to ensure compliance.
- Grid Connection: Ensure that your solar installation meets the standards for connecting to the grid, including any necessary permits and approvals.
4. Choosing the Right Equipment
- Quality and Warranty: Select high-quality solar panels and EV chargers with robust warranties to ensure durability and performance.
- Compatibility: Ensure that the solar system and charger are compatible with your EV and any existing energy management systems.
5. Professional Installation and Support
- Expert Installers: Engage professional installers with a solid track record and expertise in solar and EV integration.
- Ongoing Maintenance: Consider ongoing maintenance and support to keep your system operating efficiently and effectively over the long term.
Ready to turn your roof into your own green fuelling station? Chat with our trusted solar installer about a quick site survey to see how many panels your home can handle, and ask for a smart EV charger demo that prioritises your sunshine first. Before you know it, you’ll be cruising on homemade power, slashing your bills and your carbon footprint—one sun-fuelled kilometre at a time.
