EV charging looks straightforward until your bill tells a different story. This article breaks down why EV charging costs more than many EV owners expect, and how solar power can reduce charging costs when your solar system, electricity rates, and charging patterns are working together.
We will compare home charging versus public charging stations, then explain how solar panels reduce the cost to charge an electric vehicle. From there, we will cover solar system size and charge timing, whether a home battery and battery storage make sense or if solar plus smart charging is the better move, and the real-world limits that matter for EV Charging at home, including single phase versus 3 phase, and the key detail most people miss: the electric car’s onboard AC charger determines whether three-phase charging changes your charging rate at all.
Why Is Charging my EV So Expensive?
Charging your EV gets expensive when you are buying a lot of kilowatt-hours from the grid at prices you are not actively controlling. An electric vehicle turns electricity into fuel, so once EV Charging becomes routine, your household energy consumption rises sharply and your bill starts tracking your charging patterns. The biggest cost driver is timing: plug in after work and charge immediately, and you often land in higher Time-of-use rates rather than off-peak tariffs. At that point, you are paying premium electricity rates for a large, repeatable load.
The second driver is charging power and duration. A Level 1 EV charger is slower, which can look “cheaper,” but it extends the window you are pulling from the electricity grid, increasing the chance you drift into expensive pricing periods. A Level 2 EV charging station is faster, but it draws more kilowatts at once. If that higher draw happens during peak pricing, charging costs stack up quickly. In simple terms: EV chargers do not hunt for cheap energy—unless you schedule home charging or use energy management systems, you are letting the tariff decide what you pay.
This is where the per-kWh comparison matters. Typical home usage rates in Australia are often roughly 24c–43c per kilowatt-hour, depending on plan and network. Public charging station pricing is a different market: NSW’s guidance notes public fast charging commonly sits around 40c–80c per kWh. That gap is why “I’ll just use public charging stations” can become expensive fast—especially with DC fast chargers, where you are paying for speed and convenience, and sometimes idle fees if you stay connected after charging finishes.
Finally, there are unavoidable losses. Charging efficiency is not 100%: some energy is lost through charging cables, the charger hardware, and inside the electric car as AC electricity is converted to DC electricity for the battery. Those losses are not the main culprit, but they do increase the total kilowatt-hours you buy over time. Put it together and the pattern is consistent: EV ownership feels expensive when the grid is your primary fuel source, charging starts the moment you get home, and there is no deliberate strategy to control when you draw power.
How Solar Cuts EV Charging Costs
Solar cuts EV charging costs by reducing how many kilowatt-hours you have to buy from the grid. When your solar panels are producing solar power, your home can use that solar energy first. If your electric vehicle is charging at the same time, those kilowatt-hours come from your solar PV system instead of the electricity grid, which directly lowers electricity costs and charging costs through your electricity retailer. This is the simplest form of solar EV charging: shifting home charging away from grid supply and into on-site renewable energy generation.
The practical lever is control. EV chargers are a controllable load, and that is why a solar system can change the running cost of EV ownership more than most appliances. With a Level 2 EV charging station, you can schedule charging to sit inside solar production windows or use solar-following capability where the charger adjusts charging power to match available solar export. In other words, instead of exporting solar energy back to the grid for a lower feed-in tariff, you use that renewable generation to charge your Battery Electric Vehicle. That increases self-consumption, reduces reliance on utility rates, and can improve the return on investment of solar capacity, particularly in Australia where feed-in tariff values are often materially lower than retail electricity rates.
Solar can also reduce the need for public charging stations and DC fast chargers for day-to-day driving. If a meaningful portion of your weekly energy consumption for charging EVs is covered by solar charging at home, you are less exposed to charging networks’ pricing and idle fees. Over time, that is where the compounding savings sit: fewer paid kilowatt-hours from the grid, fewer expensive top-ups at a public charging station, and a home charging pattern that is built around solar photovoltaic output rather than convenience charging at retail rates.
Solar System Size and Charge Timing: What Actually Works for EV Owners
For EV owners, solar system size matters less than people think if the charge timing is wrong. You can install a large solar PV system, but if most charging happens after dark, you will still be buying the bulk of your kilowatt-hours from the grid at electricity rates set by your electricity retailer. The cheapest EV Charging is not created by panel count alone; it is created when solar capacity and charging patterns overlap.
Start with the only numbers that matter day to day: how many kilowatt-hours your electric vehicle needs and how many kilowatt-hours your solar system can reliably deliver during the hours the car is actually home. Most Battery Electric Vehicle drivers do not need “a full recharge” every night; they need a predictable top-up. The aim is to cover that top-up with solar energy as often as possible. That is why a Level 2 EV charging station paired with scheduling is usually the baseline upgrade for Home EV charging on solar. You set home charging to begin when solar power is high, then taper it or stop it when household load rises, instead of charging from the grid the moment you park.
Practically, there are three working charge timing strategies. The first is daytime charging when you are home: the car absorbs solar charging directly and reduces solar export credits. The second is partial daytime charging: even two or three hours of solar EV charging can offset a large portion of weekly energy consumption, while the remainder is pushed into off-peak tariffs after 10pm. The third is solar-following capability, where EV chargers adjust kilowatt draw in real time based on surplus solar photovoltaic output. This usually relies on a current transformer meter and energy management systems, and it matters because it prevents the charger from pulling from the electricity grid when clouds move through or household loads spike.
This is also where system architecture and hardware can make or break results. Microinverters versus a string solar inverter does not change the basic economics, but it can change monitoring data and how precisely you can track solar export credits versus grid imports. With the right metering in place, typically a site energy meter with CT clamps, platforms like Fronius Solar.web with a Fronius Smart Meter, Solis monitoring with a consumption meter and CTs, Sungrow iSolarCloud with an energy meter, or the Tesla Powerwall app can show the power flows that matter: solar production, household consumption, and grid import and export. The goal is simple: size the solar system to produce enough daytime solar energy, and set the charging schedule so the electric car consumes it instead of exporting it or buying it back later.
Do You Need a Home Battery for an EV (Or Just Solar + Smart Charging)?
If you own an electric vehicle and you are charging from the grid, the biggest lever to cut charging costs is usually a solar system first. Solar panels reduce EV Charging costs by replacing paid kilowatt-hours from your electricity retailer with solar power generated on your roof. Because home charging is a large, repeatable load, EV owners can often use more of their solar energy than a typical household, especially with a Level 2 EV charging station and a simple charging schedule that pushes home charging into daylight.
A home battery is the next layer, not the foundation. Battery storage extends the value of your solar system by storing solar energy and using it later, which reduces evening grid import and exposure to higher Time-of-use rates. For many EV owners, the best outcome is the combination: solar charging during the day, the house running on stored solar after sunset, and the electric car charging on off-peak tariffs overnight. Battery systems like Tesla Powerwall and Tesla Powerwall 2 are common for this because they integrate cleanly with solar and provide clear monitoring of import, export, and consumption, but the principle is the same across battery technology.
If you are choosing where to spend first, solar plus smart charging is the core move. Scheduling, solar-following capability, and a current transformer meter can increase self-consumption and reduce solar export credits lost to a low feed-in tariff. Then a home battery makes sense when you want more control over evening electricity costs, higher self-consumption, and a more complete solar-battery setup.
Single-Phase vs Three-Phase: What Your House and Your EV Can Really Charge At
Single phase versus 3 phase affects EV Charging by setting your maximum home charging rate and how the load is supplied. Think of it like water flow: single phase is one pipe feeding the charger, while 3 phase is more capacity available to feed it, so a 3 phase property can support higher Level 2 charging rates and spreads the load across phases, while single phase is more limited because all charging power comes from one phase.
The critical point is the car: the electric vehicle’s onboard AC charger determines whether three-phase makes any difference. Some EVs only accept single phase AC charging even on a 3 phase house, so they still charge at single phase rates. To know what you can really charge at, you match the property supply, the EV charging station, and the car’s onboard charger.
Single phase versus three-phase mainly affects cost indirectly through charging speed and timing. If you can charge faster on three-phase, you can fit more of your charging into cheaper off-peak tariffs or into daytime solar charging windows, which reduces what you pay per kilowatt-hour. If your EV only accepts single phase AC charging, three-phase does not lower charging costs on its own, because you are still buying the same kilowatt-hours from the grid, just more slowly. The real cost difference comes from whether your setup lets you shift charging away from expensive time-of-use rates and toward solar power or off-peak periods.
If you’re paying more than expected to charge your EV, a correctly sized solar system is one of the most direct ways to reduce ongoing charging costs. Solar Water Wind designs and installs EV-ready solar so more of your charging is supplied by solar power instead of the grid, with the inverter, metering, and charger setup needed to produce a clear reduction on your bill.
