Powering Our EV with the Sun: What We Learned (and What You Should Know)

18 June

When we first got rooftop solar, we thought we were doing our bit for the planet—and shaving a bit off the power bill. But it wasn’t until we added an electric vehicle (EV) into the mix that the full potential of our solar power really hit home.

Turns out, EV charging using solar energy isn’t just a clean choice—it’s a smart financial move too. Here’s what we learned from real-life experience, and what other homeowners should know if they’re thinking about charging their EV with solar.

Charging an EV with Solar Power: Why It’s a Game Changer

Using your home’s excess solar energy to charge your EV is one of the cheapest and cleanest ways to “fill up.” Instead of sending unused solar power back to the grid for a measly feed-in tariff (often under 10c/kWh), we used that energy ourselves.

Here’s what that meant in real terms:

Solar charging at home = ~5c/kWh
Grid electricity = ~36c/kWh
Public fast chargers = ~53c/kWh
Petrol = ~ $2.00/L equivalent

Even with public charging occasionally in the mix, solar EV charging cut our refuelling costs dramatically—and it only got better over time.

A Small Solar System Still Made a Big Impact

We don’t have a huge roof. In 2022, we installed a 3.5kW rooftop solar system on our semi-detached Sydney home—just 9 panels paired with a Sungrow inverter. On sunny days it generated up to 25kWh, more than enough to cover basic household use.

Here’s the thing: before the EV, we were exporting 75% of that energy to the grid. Working from home still didn’t shift the dial—our daytime energy use was low. So our savings? About $34 a month. At that rate, it would’ve taken 14 years to pay off the system.

Enter the EV—And a Whole New Energy Equation

When we bought our EV in 2023, everything changed. We installed an EV charger and connected it to the ChargeHQ app, which cleverly syncs your charging rate with your solar output. No guesswork, no unnecessary grid draw—just clean energy direct from the sun.

In the first 8 months, only 26% of our charging came from solar. Like many EV newbies, we experimented with public charging (and enjoyed the sneaky free parking perks). But we quickly realised those “free spots” came at a steep cost: public charging was up to 10x more expensive than charging from our own solar.

So we shifted gears. In 2024:

Solar charging jumped to 57%
Public charging dropped to 23%
Grid charging filled in the rest

As a result, we used double the solar energy we were before, and effectively doubled our solar savings. The system that once looked like a slow return suddenly halved its payback period.

By 2025, We Were Running on Sun

We made a conscious effort to plug in any time we were home. That small behavioural shift made a huge difference. By mid-2025:

Over 80% of our EV charging was solar-powered
Less than 10% came from the grid
We were using more solar energy than we exported

With energy prices rising and feed-in tariffs falling, self-consuming our solar power—especially for EV charging—is the key to real savings. And with tools like ChargeHQ or a smart EV charger, it’s easier than ever to automate the process.

What Every Solar + EV Household Should Know

You don’t need a massive solar system. Even a 3.5kW setup can unlock meaningful savings when paired with smart charging and the right behaviours.
Consider a home battery system. While we haven’t added one yet, a solar battery or battery backup could further improve solar self-consumption and offer protection during grid outages.
Most solar quotes don’t factor in EV savings. If you’re planning on getting an EV (or already have one), the real value of your solar system is probably being underestimated.
Smart charging is essential. Whether it’s an app or a smart EV charger, being able to match your charging to solar output is what maximises your clean energy use.
It’s a powerful step toward sustainable living. Charging your EV with solar not only slashes costs—it significantly cuts emissions and makes your clean energy journey go further.

Pairing rooftop solar with an EV is more than just a good idea—it’s a smart, sustainable move that delivers real financial rewards. Whether you’re already solar-powered or just starting to explore clean energy solutions, make sure your EV (now or in the future) is part of the picture. Because when the sun powers your home and your wheels, that’s when solar energy really shines.