By: Byron Mathioudakis

Just how much cheaper is it to ‘fuel’ an electric car and how do you work it out?

The Australian automotive landscape is changing… and fast.

In 2021, sales of electric vehicles (EV) as well as plug-in hybrid electric vehicles (PHEV) were at about 1.6 per cent of total new vehicle registrations. An all-time high back then, that was nearly twice as many as the year before, though a fraction of other similarly sized markets.

Just two years later in 2023, that number increased five-fold, to an 8.1 per cent share. You can double that figure to over 16 per cent if you include regular, non-plug-in hybrids like the Toyota RAV4.

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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 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 energy. Nowadays, in modern battery EVs, they range from about 40kWh to over 110kWh. Most are in the 60kWh to 90kWh 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 – and time – to charge it up.

WA electricity prices

From July 1, 2024, the Western Australian government’s standard, A2 Residential (household) tariff has been set at 31.5823 cents per kilowatt hour (kWh) plus a 113.22c per day supply charge. This is at any time of the day or night and regardless of location.

Energy retailers Horizon and Western Power’s Synergy have a standard 30.81c rate combined with a 110.46c daily charge. As of publishing, the varying smart meter rates are set at (a rounded-up) 53c/kWh (peak), 23.5c (shoulder) and 8.5c/kWh (off-peak).

Solar panels on residential roof

Synergy’s ‘EV Add-On’ tariff jumps 3c/day to 126.075c/day, along with its overnight electricity charge rate, rising about half a cent to 18.9113c/kWh.

From July 1, for small to medium businesses, the regulated price varies between around 30.83 and 36.33 cents per kWh, depending on usage rates. Smart meter rates are currently at 16.21c/ kWh for off-peak and 54c/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 available solar energy 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 of 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 your home power points, and it’s recommended for maximum EV battery health, as regular DC fast charging slightly decreases your vehicle’s traction battery life.

But 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 for most EVs it can take between 25 and 45 hours to fully charge. This roughly equates to about 15km per hour of charge. It works well for daily ‘top-ups’ of an EV battery, but it’s better suited to PHEVs since their batteries are a lot smaller than those of a pure EV.

Electric car charging in home garage

Note, too, that the AC charging capacity of an EV is variable. Some can only handle 7.4kW though many are increasing to 11kW and even 22kW.

Buying an at-home charger multiplies the amount of AC charge, from between 7.4kW (starting from about $1,500 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.

To reiterate, AC home (or workplace) charging is the most common and convenient, as well as safest for your EV’s battery, and you can plug it in while your car isn’t needed overnight or during your workday. Keep in mind, too, that with solar panels installed, you can charge your EV for free utilising the energy produced on your roof – if you’re at home.

DC fast charging is primarily available at public charging stations, and provides energy at rates ranging from 50kW, 100kW, 150kW and up to 350kW for your EV. Most are limited to 100kW, and 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.

Mid-size SUVs: EV versus petrol

The bestselling EV in Australia by some margin is the Tesla Model Y midsized SUV, accounting for 33 per cent of total EV sales in 2023, followed by the closely-related Tesla Model 3 sedan at 20 per cent.

Prices for some EVs have been dropping as competition increases, and prices are set to fall even more over time.

As our first example, let’s use the Model Y Standard Range Rear-Wheel Drive grade with a circa-60kWh battery (Tesla does not disclose exact specifications) from about $60,000.

Using the WA Government’s 31.5823 cents per kilowatt hour (kWh) standard and then rounding up to work out the price-per-kWh (in this case $0.32 per kWh multiplied by the 60kWh battery size) means that it presently costs $19.20 plus $1.14 supply charge to top-up a Model Y RWD from empty to full at a residential address in WA. That’s $20.34.

Allowing for the fact that all EV batteries have built-in protections that prevent their batteries being fully depleted and fully charged, the Tesla battery’s chargeable amount is about 57.5kWh, at 31.6 cents per kWh, the maximum you’d pay is $18.17/$19.31 with Supply Charge.

Tesla Model 3 electric car

If you have a suitable meter and are otherwise eligible for the EV Add-On Overnight Tariff rate of 18.9c/kWh ($0.19), it’d mean the Model Y’s cost per charge falls to $12.61 (including additional supply charge tariff), or even further, to just $6.24, if eligible for the lowest off-peak rate. Conversely, at the high-peak rate, it’s still under $33.

So, at around $20, how does this compare to a comparably sized and priced ICE rival, such as the popular Mazda CX-60 G40e Evolve? Filling the latter’s 58-litre fuel tank (allowing a five-litre buffer) with 53 litres of the recommended 91 RON unleaded petrol at $1.85 per litre means it would cost $99.05 to fill.

Get on the highway though, and things change a little. To go 100km, the Mazda will need six litres of petrol at $1.85/L, translating to $11.10.

The Tesla will need 18.5kWh/100km (according to EV Database), and if you use public fast-charging stations along the way at 60 cents per kWh, the cost (somewhat coincidentally) turns out to be the same at $11.10 per 100km.

Also, you won’t be worrying about charging (and waiting to charge) on a long trip in the Mazda, but it will be more expensive to run in urban areas than the Tesla.

Small SUVs: EVs versus a plug-in hybrid EVs (PHEV)

Does a different picture emerge when comparing an EV with a PHEV?

Let’s look at two popular examples – the Hyundai Kona Electric Standard Range EV from $54,000 and the similarly-sized Mitsubishi Eclipse Cross Aspire AWD PHEV from $51,740, and both before on-road costs.

At the 31.6 cents per kWh tariff plus supply charge and applying a 2.5kWh charging buffer as per the Tesla above, charging the Kona’s 48.6kWh battery costs nearly $14.57, while the Mitsubishi’s much smaller 13.8kWh battery only costs about $5.02 if we factor in a smaller buffer of 1.5kWh to base the charging cost on 12.3kWh.

But the Kona Electric offers a 370km WLTP range, meaning it can travel nearly seven times further on a charge compared to the Eclipse Cross PHEV’s 55km electric-only range.

A blue Mitsubishi Eclipse Cross PHEV

However, PHEVs are all about quelling range anxiety compared to EVs thanks to their internal combustion engine. This means that filling the Mitsubishi’s 45L fuel tank will add $74 (factoring in a 5L buffer taking it to 40L) more to your costs using the recommended 91 RON unleaded petrol at $1.85 per litre – for a combined total of $79.02. The laboratory test is favourably suited to PHEV vehicles and can often generate results that are optimistic compared to the real-world driving experience, depending on how the vehicle is used.

Regular charging will significantly extend your time between petrol fill-ups in the PHEV, but if charging at home, it’s likely the Kona will be cheaper. Though the Kona won’t alleviate range anxiety as well as the Eclipse Cross PHEV, if you’re so inclined.

Small cars: EV versus hybrid

The evergreen Toyota Corolla SX hybrid is nearly the same price as the entry-level MG 4 Excite 51 at $40,000.

At the 31.6 cents per kWh tariff plus supply charge, it would cost around $16.46 to charge the MG 4’s 51kWh battery (including a 2.5kWh charging buffer), against nearly $70.30 to put 38 litres into the Corolla hybrid’s 43L fuel tank using 91 RON unleaded petrol at $1.85.

While the MG 4 offers a 350km WLTP range, the Corolla hybrid can go up to 1075km between refills, and it never needs to be plugged in as its tiny 1.3kWh battery is primarily recharged by the engine. To match that distance in the EV, you’ll need to charge it 3.1 times but even that still comes in much cheaper, at under $55.

An orange MG4 EV

Again, the numbers will vary on the highway. Like the Tesla mentioned here, the MG4 51KWh is quoted by EV Database as needing 18.5kWh to go 100km. If public chargers are used on a longer highway trip at 60c per kWh, it’ll cost $11.10. The Corolla needs 4.3L per 100km on the highway, which at $1.85 per litre, will cost $7.95.

However, the costs of using DC (direct current) public EV chargers do vary and RAC members have access to a 20 per cent discount on public charging along the RAC Electric Highway®.

Public chargers

Public chargers can provide on average from 150km (or more) per hour of charge, from about 45 cents to 70 cents per kWh maximum up to about 150kW, depending on the time of day, demand and other factors. Ultra-powerful chargers (from 150kW to 300kW) can cost up to 90 cents or more per kWh.

Using the vehicles from the household charging examples mentioned above, at a DC charger with a 60 cents per kWh tariff, our Tesla Model Y’s 60kWh battery would cost $36, the Hyundai Kona Electric Standard Range’s 48.6kW battery would cost $29.16 and the MG 4 Excite’s 51kWh battery would cost $30.60 to replenish (where the full battery capacity is used).

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

These often help make EVs work out cheaper than their ICE counterparts.

Currently, there are around 4000 public chargers nationwide, but fewer than 1000 are of the fast DC variety that can add hundreds of kilometres of range in under one hour.

According to the Electric Vehicle Council of Australia, out of 79 in WA, 39 were of the ultra-fast variety by the end of 2023.

The RAC Electric Highway® today has publicly accessible charging stations located between Monkey Mia and Esperance (via Perth and Pemberton) totalling over 2160km, including fast and ultra-rapid charging stations.

EV charger at RAC Head Office

In early 2024, the WA government announced a fast-charging station network upgrade to create Australia’s longest EV charging network. Dubbed the WA EV Network, and connecting Perth to regional WA, it will include “…98 EV charging stations across 49 locations, from Eucla at the South Australian border to Kununurra in the far north of Western Australia.”

The rapid uptake of EVs in Australia over the past four years 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.

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