How Much Does it Cost to Charge an Electric Car (EV)?

The cost of charging an electric car (EV) varies depending on four main factors: battery size, battery type, charging method and solar power vs. grid power. The EV battery’s cost-efficiency varies by size and type. Smaller batteries can be more efficient and cost less to charge. Lithium-iron-phosphate (LFP) is the lowest-cost battery type. The charging methods available are alternative current (AC) or direct current (DC), with AC charging being cheaper than DC charging. Additionally, the use of solar power or grid power affects costs differently. Solar charging maximises an individual’s savings by avoiding grid energy costs. 

Battery size

Measurements referenced:

• Kilogram (kg) is a measure of mass. A kilogram is equivalent to 1000 grams. 
• Kilowatt (kW) is a measure of power consumed over time. A kilowatt is equivalent to 1000 watts. 
• Kilowatt-hour (kWh) is a measure of power output over an hour.
• Kilometre per hour (km/h) is a measure of distance over time used in the metric system. It’s equivalent to 1000 metres over an hour. 
• Watt-hour per kilometre (Wh/km) measures power output. Watt-hour is used to determine efficiency. 

Battery size can influence charging costs. A larger EV battery will typically have a greater capacity and range but not necessarily a greater efficiency. Greater efficiency can often mean lower charging costs. 

To illustrate this point, let’s compare two Volkswagen models. The Volkswagen ID.3 Pure Performance is a small hatchback, and the Volkswagen ID.4 1st Edition is a medium SUV. The Volkswagen ID.4 has a greater battery capacity, range, and charging rate, whereas the Volkswagen ID.3 has a shorter charge time of one hour and twelve minutes and a better efficiency rating. The Volkswagen ID.4 may be more convenient due to its greater range and capacity, meaning less frequent charging is necessary. However, the higher efficiency rating of the Volkswagen ID.3 translates to a lower cost per km.

You can calculate the cost of charging a particular EV battery by multiplying the capacity of the electric vehicle battery in kWh with the cost of electricity per kWh. Let’s assume a household’s grid electricity cost is Synergy’s A1 tariff which is $0.30 per kWh consumed. At $0.30 per kWh, the Volkswagen ID.3 would have a charge cost of $13.50, and the Volkswagen ID.4 would have a charge cost of $23.10. To calculate the cost per kilometre, you can divide the charging cost by the range of the vehicle. In this case, that would amount to 4.90 cents per kilometre for the ID.3 and 5.63 cents per kilometre for the ID.4. This demonstrates that a smaller EV battery with greater efficiency can prove more cost-effective. 

This table shows Volkswagen’s ID.4’s battery performance compared to the ID.3.

Battery type

New measurements referenced:

• Volts (V) measure electromotive force. 
• Energy density refers to the amount of energy stored in a volume of space. 
• Cycles (or charge cycles) refer to one complete charge and discharge of a battery. 
  

Most EV batteries in use today are lithium-ion batteries because of their superior efficiency, cycle life and Wh/kg energy ratings. There are three primary subcategories of lithium-ion batteries. These are lithium-iron-phosphate (LFP), nickel-manganese-cobalt (NMC) and nickel-cobalt-aluminium (NCA). NMC and NCA are similar in their features, whilst LFP batteries are comparatively distinct. The main differences are that NMC and NCA batteries are made using rarer materials and have a higher energy density. The energy density of NMC and NCA batteries is based on their nickel proportion.

Lithium-iron-phosphate (LFP) battery advantages 

LFP batteries have five main advantages compared to NMC and NCA lithium-ion batteries. These are the availability of materials, longer lifespan, ability to fully charge, affordability, and high temperature tolerance.

The five advantages of lithium-iron-phosphate (LFP) batteries are:

• LFP batteries are manufactured using more available materials. This makes them easier to produce and more sustainable.
• LFP batteries outlive NMC and NCA batteries. They have more cycles and degrade slower. LFP batteries can remain at 80% capacity after 3000 cycles. Most NMC and NCA batteries drop to 60% capacity after 1000 cycles.
• LFP batteries can be charged to full capacity. NMC and NCA batteries can experience damage from charging fully.
• LFP batteries are cheaper because they are made from more readily available materials. 
• LFP batteries tolerate high temperatures, making them less likely to catch fire when encountering a short circuit. They are the safest battery chemistry on the market.

LFP battery disadvantages

LFP batteries have four main disadvantages compared to NMC and NCA batteries. These are slower charging, lower suitability to high performance, lower efficiency, larger size and lower range. 

The disadvantages of LFP batteries:

• LFP batteries charge slower than NCA and NMC batteries. However, there’s no difference at temperatures lower than 10 ^oC. As temperature increases, the difference increases, with NMC and NCA batteries charging faster.
• LFP batteries' lower energy density lowers their maximum discharge power. This means electricity is transferred slower from the battery.
• LFP batteries require more space than NMC and NCA batteries. This is a result of lower energy density, needing more space to carry the same amount of energy. This means the EV needs to account for more space weight to hold the battery. Over time, LFP batteries have decreased in size.
• LFP batteries have a lower range. Their larger size and lower capacity limit the range of the EV. This results in needing to charge more frequently. 
  

NMC and NCA battery advantages

NMC and NCA batteries have six main advantages compared to LFP batteries. These are faster charging, suitability to high performance, higher efficiency, smaller size, larger range, and better low-temperature performance.

• NMC and NCA batteries charge faster than LFP batteries. This is compounded as temperature rises.
• High performance suits NMC and NCA batteries. Their higher energy density results in discharging power quicker.
• Efficiency is increased with NMC and NCA batteries. Their higher energy density makes their output of kWh greater than LFP batteries of the same capacity.
• NMC and NCA batteries require less space. Their lower energy density gives them more power for less volume.
• NMC and NCA batteries have a larger range. This is due to their higher capacity and efficiency. This means they can be charged less frequently.
• Low temperatures are resisted by NMC and NCA batteries. They can utilise the vast majority of their capacity in negative Celsius temperatures. 
  

NMC and NCA disadvantages

NMC and NCA batteries have four primary disadvantages compared to LFP batteries. These are rarer materials of higher cost, shorter longevity, and lower sustainability.

• Rare materials are needed for NMC and NCA batteries. Materials like cobalt and nickel are scarce in the earth’s crust. This leads to difficulties in sourcing them.
• NMC and NCA batteries have higher costs. This is a result of the materials used in manufacturing.
• NMC and NCA batteries degrade in less time. They have fewer cycles than LFP batteries. They begin to degrade more significantly and in less time than LFP batteries.
• Sustainability suffers in NMC and NCA batteries. They use rare materials, degrade faster and are recycled less easily than LFP batteries. This makes NMC and NCA batteries less viable as long-term battery types. 

Types of charging

New measurements referenced:

• Amperes (A) measure how much electrical charge is moving over time. 

There are two main types of charging for electric car batteries. These are alternating current (AC) and direct current (DC) charging. AC’s electric current flow changes direction periodically, whereas DC is linear and flows in a single direction. AC power is suited to travelling further than DC power. This makes it more suitable for the power grid. DC power is more effective at delivering higher voltages from the power source to the recipient. An electric car battery is only capable of accepting DC. This means AC power must be converted to DC before it reaches the battery. EVs have in-built chargers that convert AC into DC for the battery. 

Alternating current (AC) charging

Alternating current (AC) charging is slower than direct current (DC) charging. This is because of AC power sources and the necessary conversion of AC to DC power for battery storage. Firstly, AC is drawn from the grid, which delivers power at lower levels than DC power sources. This is compounded by the EV’s onboard charger needing to be lightweight. The weight limit results in lower power output capacity. Secondly, the onboard charger of the EV converts AC from the power source into DC for the battery. The charging is slowed down further by the conversion process. Losses from conversion depend on the converter’s efficiency. 

Single-phase and three-phase power

Single-phase or three-phase power influence the charging time of an EV battery. Single-phase electricity uses one power line to deliver electricity to a home, whereas three-phase electricity uses three. As a result, three-phase supplies a higher amount of power. For example, a 10A power source charges a battery at a rate of 7.2 kW using three-phase compared to 2.4 kW using single-phase. The majority of Australian homes use single-phase power. You can check how many phases your home uses by looking at your fuse box. The power is three-phase if there are three main switches or three fuse cartridges. 

There are two different levels of AC charging with varying capacities for delivering electricity to the car battery. These are level 1 and level 2. 

Level 1

Level 1 AC chargers are the slowest and cheapest way to charge your EV. The two necessary components are a power point and a portable charger. Portable chargers will come with your EV. If you have a compatible power point, you only need to plug it in for charging. Power points vary in how much current they can supply; in Australia, they typically have a current rating of 10A. However, a licensed electrician can upgrade your power point. Portable chargers packaged with an EV are typically limited to supporting 10A outputs. Buying a faster charger is possible but will cost more. There is no additional charging cost by using your EV’s included charger with a household powerpoint. However, upgrading your power point can cost between $80 and $400. A more powerful portable charger will cost between $400 and $900. 

Level 2

Level 2 AC chargers use a specialised wall-mounted charging unit. This is installed in the home and connected to a power source. Level 2 AC chargers are faster than level 1 chargers if they receive sufficient current from their power source. They can be installed at 15A or 32A, exceeding the charging speed of level 1 AC chargers. A level 2 AC charger needs to be installed by a licensed electrician. Installation costs are typically between $300 and $1500 but can be higher. The cost of the level 2 charger itself ranges between $600 and $2500, depending on its brand and features. 

Smart charging

Level 2 AC chargers installed at home can have smart charging features. Smart charging utilises real-time data from your home devices to automate charging. You configure the smart charger according to your preferences, and it optimises the charging process in three ways. These are scheduling smart solar charging and load balancing. Firstly, scheduling involves setting specific times for your charger to charge your EV. This makes charging cheaper by preferencing off-peak times with lower electricity costs. Limiting charging to off-peak times can potentially reduce charging costs by 74% compared to peak times. (If you’re using solar, you’re getting your energy for free, but a similar rule applies: you want to charge your EV during peak generation times, usually 10 am - 2 pm.) Secondly, smart chargers can communicate with your solar system. This lets them adjust their charging rate according to the available power generated. Excess energy from your solar system can be diverted to your electric car instead of the grid. Thirdly, load balancing ensures you can charge everything you need to without causing a power outage at your home. Smart charging communicates with your household circuits to adjust to the available power load and not exceed it. This maximises the output of the charger while avoiding overloading the power system. 

Direct current (DC) charging (level 3 charging)

Direct current (DC) charging (also known as level 3 charging) is available at public DC charging stations. DC charging stations take the AC current from the grid and convert it to DC.  DC charging sends an electrical current straight to the car battery since it has already converted the AC from the grid into DC. DC requires higher voltage and amperage, meaning it transfers a greater amount of electricity. They are the fastest and most expensive charging method available for electric cars. The cost of DC charging is typically between $0.30 and $0.60 per kWh. The total cost depends on the EV’s battery capacity. 

Should you charge an EV with solar power or grid power?

When charging an electric car at home, you have two choices. You can use power from the grid or solar power generated by your solar system. Both sources have potential advantages and disadvantages. 

Solar feed-in tariff

The solar feed-in tariff is a payment you receive for the excess energy your solar system generates. When your solar panels produce more energy than your home requires, or once your solar battery is fully charged, the excess energy is fed back into the grid. You are then paid based on how much energy your system exports. The amount paid varies by location and time of day. Different states have different tariff rates depending on the energy retailer. Off-peak hours refer to periods with lower electricity demand. On-peak hours refer to periods of the day and week with higher electricity demand. Shoulder periods refer to every other period. Charging is cheapest during off-peak and shoulder hours, and this is when the feed-in tariff is at its lowest. The lowest amount is paid through the tariff during shoulder periods. The highest amount is paid through the tariff during on-peak times (the period when overall energy use is the highest). 

When solar was first implemented in Australia, feed-in tariffs were high and provided a financial return for owners who exported their excess solar power to the grid. In 2022, the solar feed-in tariff has heavily declined (in Western Australia, it’s as low as 2.25 cents per kWh exported) and cannot cover the cost of the power pulled from the grid. This is why solar batteries have become a necessity for most Australian households. You can read more in our article What Are Feed-In Tariffs?.

Charging your EV with solar power

Advantages

Charging your electric car with solar power saves you money on your electrical bills if you have a solar + battery system. However, ensuring your solar + battery system is the right size is imperative.  If you have a solar system large enough to produce and store the energy needed to charge your EV, you won’t have to pull from the costly electrical grid. You’ll also be helping the environment! Not only will you be driving an electric car that doesn’t emit pollutants, but you won’t be charging it with energy produced by a coal or gas power station.

Disadvantages

There aren’t really any disadvantages to charging your EV with the solar power created by your solar panels. However, two disadvantages of charging your electric car with your solar battery are lacking charging efficiency and decreasing the solar battery’s longevity. Firstly, each time DC power is converted to AC power and vice versa, there’s power that’s lost in the conversion. So each time power comes in and out of your battery, a very small percentage will be lost in the transfer. However, the savings you receive from using solar power instead of grid power make up for this lost energy. Secondly, all solar batteries have a cycle life. Charging an EV with a solar battery will up the number of daily cycles a battery undertakes, resulting in reaching the end of the cycle life quicker. As solar batteries’ cycle lives continue to grow, this is less of an issue. The future of an Australian household is a self-reliant, solar-powered house and car, and the improvement in solar batteries’ cycle lives reflects this.

Charging your EV with grid power

Advantages

Charging from the grid provides greater efficiency because there is less energy ‘lost’ in the process. Batteries experience power losses when charging or discharging. When transferring power from a solar battery to an EV battery, double the battery losses occur due to two batteries being involved. Charging directly from the grid only involves the losses from the EV battery charging.

Disadvantages

The biggest disadvantage of using the grid to charge your EV is the cost. As energy costs continue to rise, many Australians are feeling the financial pinch when their electricity bills arrive. Charging your EV with grid power is going to drive your bills up. Trying to charge your car in off-peak times will help, but in comparison to free solar power, it’s an expensive endeavour. Additionally, many people purchase electric cars in order to live more environmentally friendly. While this is undoubtedly what we all need to do, by charging an EV with grid power, you’re using gas and coal power stations that severely harm our planet. Why swap one fossil fuel for another when there’s a cleaner alternative?

Are there electric cars (EVs) with solar panel roofs?

There are electric car (EV) models on the market with solar panel roofs. These can be a feature or an option. The aim of a car with a solar panel roof is to allow the vehicle to charge while driving or parked in sunlight. 

The four advantages of electric cars (EVs) with solar panel roofs:

• Range is increased for the EV. The supplied energy throughout the day offsets the energy spent.
• EV batteries can be charged with sunlight. They don’t require a grid or solar system connection.
• Cost is mitigated over time. Sunlight is freely available and maximises accumulative savings.
• Protection is given to the battery. Batteries can be damaged if their charge level drops too low from underuse. Solar charging keeps the battery’s charge level high.

The six disadvantages of electric cars (EVs) with solar panel roofs:

1. Solar panels increase costs. An EV with solar panels will be more expensive upfront due to solar panel manufacturing costs.
2. Roof space is required for solar panels. This makes them a less viable option for smaller vehicles. However, some new models are utilising solar panels more effectively on EVs. 
3. Batteries can deteriorate at higher rates. Parking in the sun to charge your electric car heats up the battery. This can lead to damage over time.
4. Solar panels are laid flat on the roof. This isn’t the most effective angle for utilising solar power. It will decrease the solar panels' output.
5. Maintenance requirements increase for solar panels. Solar panels must remain clean for effective functioning. Solar panels on an EV are more susceptible to dirt than roof solar panels and require regular cleaning.
6. Solar panels depend on sunlight. So if your car is parked indoors, it’s night-time or overcast, the EV’s solar panels won’t be able to charge the vehicle.
   

Can you charge an electric car (EV) with portable solar panels?

You can charge an EV with mobile solar panels. This requires a solar generator and portable solar panels. However, this method is inefficient compared to charging from a solar system, solar battery or charging station. It requires a large number of solar panels for sufficient power generation. Additionally, solar panels decay over time. This means their charging capacity decreases during charging. They can be useful for emergencies but are not viable for regular EV charging. 

The number of portable solar panels necessary to charge your EV depends on two main factors. These are the size of the electric car battery and the type of solar panels you are using. Firstly, larger car batteries have greater capacities. This means more charging is required to fill them up. Secondly, different types of solar panels have different specifications. Panels with a higher power capacity generate power more effectively. This means you can use less of them compared to panels with lower power capacities. 

Could an electric car (EV) battery power a home?

An electric car battery can potentially charge a home. Most EVs use a monodirectional charger, which charges in one direction. Bidirectional chargers allow charging to occur in two directions. EVs with CHAdeMO charge ports are compatible with bidirectional chargers. An electric car using a bidirectional charger can power a home.  

While it is possible to power your home with an EV battery, in the current technological space, it’s not recommended because of the cost, EV availability and finite storage space. Firstly, electric vehicles are significantly more expensive than solar batteries. Buying an EV for the purpose of home charging is not cost-efficient. Secondly, your EV will not be constantly available to store power. You will be using it for transport, limiting its time at home. Thirdly, it may not have power available. The capacity of some new EV batteries may be sufficient for charging a home; however, driving uses battery power, leaving less available. This being said, look out for EV batteries being used as a supplementary power source in the coming years.

EV incentives 

Across Australia, there are government incentives for buying an electric vehicle. Western Australia has a rebate of $3500 for electric vehicles costing less than $70,000. This only applies to the first 10,000 people to purchase an electric vehicle after May 10th, 2022. 

Petrol vs EV charging comparison

Petrol is more expensive than all existing EV charging methods. MG ZS small SUVs have petrol and EV variants, making them suitable for comparing charging and petrol costs over 100 km.  Assuming petrol costs are approximately $2.00 per litre, it would cost you $17 per 100 km. Fast charging an electric vehicle would cost $6.12 per 100 km. Grid charging from home would cost you $3.06 per 100 km. Charging with solar from home would cost $0.46 per 100 km. Charging your vehicle with your residential solar system can therefore save you approximately $16.54 per 100 km. It is worth noting that EVs can not travel as far as traditional vehicles, requiring more frequent charging.

Power your EV with a solar + battery system

By powering your EV with a solar + battery system, you can not only maximise your fuel and electricity savings but also help the environment. Here at Plico, we want everyone to be able to adopt solar, which is why we’ve created a new payment model with no big upfront costs and one low weekly fee. Additionally, Plico members receive 10 years of ongoing support.

Plico member Josh uses his solar + battery system to power both his home and his electric car.

Interested in a solar + battery system? You can shop Plico’s solar + battery systems, or check out Plico’s new battery-only offerings. Alternatively, have a chat with a switched-on Plico team member on 1300 175 426 to discuss your individual needs, or fill out the form below and we'll get back to you.

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