What does it cost to charge an electric car?

By: Byron Mathioudakis

In 2021, sales of electric vehicles (EV) as well as plug-in hybrid electric vehicles (PHEV) in Australia soared by nearly 170 per cent in the first half of the year compared to 2020 levels.

While they're still only about 1.6 per cent of total new vehicle registrations (in similarly sized markets elsewhere their share is up to 10 times that of Australia’s) there’s no denying that EVs are becoming hot property.

If you’re thinking of making the switch from an internal combustion engine (ICE) petrol, diesel or hybrid vehicle to a fully battery-powered EV, there are many things you’ll want to know – including how much it costs to charge one.

It's important to emphasise that there isn’t a straightforward answer to this question, as there are many variables that determine what EV owners or drivers must pay as far as ‘filling up’ an EV is concerned, starting with the size of the battery.

Keep in mind that EV batteries are essentially ‘fuel tanks’ in that they store electricity. In modern battery EVs of the 2020s, they range from about 24kWh to over 100kWh. Most are in the 45kWh to 65kWh bracket.

Two things need to be remembered: firstly, the bigger the battery, the more expensive the vehicle is to buy; and secondly, it will need more electricity to charge it up. That’s simple enough.

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WA electricity prices

As of 1 July 2021, the Western Australian government regulated the cost of standard household electricity, to just over 29.3 cents per kilowatt hour (kWh).

However, with smart meters now rolling out, off-peak (9pm-7am) and peak (3pm-9pm) charges are currently at 15.1 and 54.8 cents per kWh respectively, with a shoulder rate set at 28.7 cents per kWh between 7am-3pm weekdays and 7am-9pm on weekends.

For small to medium businesses, the regulated price varies between around 28.9 and 32.6 cents per kWh, depending on usage rates. Smart meter rates are currently at 16.25 cents per kWh for off-peak and 54.1 cents per kWh during peak periods.

Adding solar panels can save thousands of dollars annually depending on the system’s size and output, and can start from around $4,000 installed for a reputable 3kW system, $5,500 for a 5kW system or upwards of $10,000 for a 10kW system. By the way, Perth beats Brisbane in terms of generating most solar power amongst the Australian capitals,  thanks to an average of 5.34 hours of sunlight per square metre, according to the Bureau of Meteorology.

The cost charging your EV at home

There are two types of charging: AC (alternating current) which is slower, and DC (direct current) which is faster.

AC is what you have at home. If you use a normal power point, you will only have access to 1.4kW to 2.4kW of power flowing through at any given time, which means in most EVs it can take between 25 and 45 hours to fully charge. This roughly equates to about 15km per hour of charge. This works well for daily ‘top-ups’ of an EV battery – just like a smartphone. It also works well for PHEVs since their batteries are a lot smaller than a pure EV and can be topped up by their internal combustion engine and regenerative braking.

Buying an at-home charger multiplies the amount of AC charge, from between 7.4kW (starting at about $1,000 to buy) to 22kW ($3,000 and up depending on quality). These reduce charging times to about 15 hours for the former and to under 10 hours for the latter. However, the AC charging capacity of an EV is variable. Some can only handle 7.4kW.

At home charging is the most common and convenient, plugging in when you get home and leaving your car to charge.

There is also fast DC charging at public charging stations, that provide from 50kW, 100kW, 150kW and even 350kW of electricity for your EV. Most vehicles are limited to 100kW, older EVs can’t take more than 50kW, but some higher-end performance/luxury models can be fully recharged in a little over half-an-hour from near-empty.

EV versus petrol for a mid-size luxury sedan

The bestselling EV in Australia in 2021 is the Tesla Model 3, accounting for over one-third of total sales in the first half of 2021 and driving EV uptake like no other in Australia.

So, as our first example let’s use the Standard Range Plus model (SR+) fitted with a 55kWh battery pack, a single motor and rear-wheel drive which costs from $59,990 (before on-road costs). Its battery size happens to be a bit bigger than a base Nissan Leaf’s (40kWh) and slightly smaller than a Hyundai Kona Electric’s extended range (64kWh).

Multiplying the price-per-kWh (in this case 29.3 cents or $0.293 per kWh) by battery size (55kWh for the Tesla) means it presently costs just $16.12 to charge a Model 3 SR+ from empty to full at home in WA. Note: these figures are all academic, as all EVs have a buffer (or a little in reserve) that stops a full 100 per cent charge as well as depletion to 0 per cent, to preserve battery life. As the Tesla battery’s chargeable amount is 52.5kWh, at 29.3 cents per kWh, the maximum you’d pay is $15.39.

The Model 3 SR+’s cost per charge plummets to just over $8.30 at household off-peak rates, or as much as $30.14 at the current maximum smart meter rate of 58.4 cents in WA.

How does this compare to a comparably powered premium ICE rival, such as a Mercedes-Benz CLA 250 4Matic? Filling the latter’s 51-litre fuel tank with the recommended 95 RON premium unleaded petrol at $1.55 per litre means it would cost $79.05 to fill.

That’s quite a contrast, and even though the Tesla offers an official 448km range on the World Harmonised Light Vehicle Testing Procedure (WLTP) compared to 761km between refills for the Mercedes, the Model 3 still comes out as being much cheaper to 'fuel’.

Of, course charging with solar panels that are already installed, can mean you can charge your EV for free utilising the energy produced on your roof.

EV versus a plug-in hybrid EV (PHEV) for a compact SUV

However, the picture changes when comparing an EV with a PHEV.

For instance, an MG ZS EV from $44,990 drive-away is nearly the same size and price as the new Mitsubishi Eclipse Cross Plug-in Hybrid from $46,490 before on-road costs.

At the 29.3 cents per kWh tariff, charging the MG’s 42.5kWh battery costs just $12.45 while the Mitsubishi’s much smaller 13.8kWh battery only costs $4.04. But the ZS EV offers a 263km WLTP range, meaning it can travel nearly five times further on a charge compared to the Eclipse Cross PHEV’s 55km electric range.

However, filling the Mitsubishi’s big 63L fuel tank will add $88 more to your costs using the recommended 91 RON unleaded petrol at $1.40 cents per litre (for a total of $92).

EV versus hybrid for a small car

The $49,990 Nissan Leaf’s 40kWh battery at the current 29.3 cents per kWh rate would cost $11.72 to charge.

The similarly sized, priced and equipped Toyota Prius i-Tech’s 43L fuel tank means it costs $60.20 to refuel using 91 RON unleaded petrol.

Here’s the interesting thing. The Leaf only has a 270km range (on the World Harmonised Light Vehicle Testing Procedure), while the Prius has a much bigger 1265km average on one tank, and it never needs to be plugged in as its tiny 1.3kWh battery is primarily recharged by the engine. So, there’s only a $5 difference in the cost between ‘refuelling’ the two, and in the EV’s favour. So, the EV is slightly cheaper.

Public chargers

The cost of using DC (direct current) public EV chargers can vary widely. They can provide on average from 150km (or more) per hour of charge at about 45 cents to 60 cents per kWh maximum, depending on the time of day, demand and other factors.

Using the vehicles from the household charging examples mentioned above, our Tesla Model 3 SR+’s 55kWh battery would cost $24.75 at the 45c tariff, the MG ZS EV’s 42.5kW battery would cost $19.13 and the Nissan Leaf’s 40kWh battery would cost $18 to replenish.

Note that these prices would be reduced substantially according to the amount of remaining charge before plugging your EV in. Additionally, some public charger suppliers offer discounts, such as the first few kWh supplied for free, shaving a few dollars off.

Either way, these still work out cheaper than their ICE counterparts.

According to Australia’s Electric Vehicle Council, there are more than 3000 public chargers nationwide, but fewer than 480 are of the fast DC variety that can add hundreds of kilometres of range in under one hour.

The RAC Electric Highway® today has publicly accessible charging stations located between Perth and Pemberton (over 610km), including fast and ultra-rapid charging stations.

According to Plugshare.com WA has a total of 33 DC chargers and just over 230 AC chargers, for a combined total of over 260 chargers to date. There is also a further network of three phase power outlets across the state.

In August 2021, the WA government announced a fast-charging station network upgrade, with “up to” 90 additional stations and back-up chargers at 45 locations earmarked to be built by 2024.

Connecting Perth and regional Western Australia, it will extend up north to Kununurra (taking in Karratha, Broome and Fitzroy Crossing), south to Esperance and east to Kalgoorlie, with average distance stated as being “around 160 kilometres” apart. These gaps will preclude some early EVs like the original Nissan Leaf (ZE0 from 2011 to 2017) and pre-2019 BMW i3 EV update, but should be fine for most others.

The rapid uptake of EVs in Australia over the past 18 months will only continue to grow, as carmakers transition from ICE to electrification to meet the necessary, increasingly stringent emissions standards proposed over the next decade. From the 2030s onwards, many countries are planning to phase out new ICE vehicle sales altogether.

What this means for Australians is that the infrastructure will continue to improve, prices will drop as competition hots up and, as technologies evolve, concerns about range, location and availability will continue to diminish.

Last updated: October 2021