Tesla Owners Club Western Australia-

When people discuss driving from coast to coast in Australia they often say we’re driving the Nullarbor. Before the road was completely sealed in the mid 1970s it was at best a challenging experience, at worst a mighty test of patience for those who didn’t plan for tyre and suspension issues along the way. These days the road is fairly good, the biggest challenges are rapid temperature changes, the often relentless wind and the flies.

As a matter of reference the Nullarbor Plain is an area located between the towns of Norseman and Ceduna, these two towns are 1200kms apart by road although the true treeless part (that still has a random small tree along the way) is mostly between the West Australian border and the Nullarbor roadhouse in South Australia, for this exercise an across the Nullarbor drive is between Perth and Adelaide via the shortest route of 2724kms.

The first time I drove across the Nullarbor was in 1992, in the past 3 years we’ve driven it 3 times in an electric vehicle. It’s an interesting adventure charging from 3 phase outlets and answering questions from curious tourists, the journey is not difficult at all, it just takes planning and patience. Driving these long distance trips with charging downtime also provides plenty of opportunity to think of the possibilities of where to install DC chargers and what charging speeds would be best. The installation of equipment that reduce charging time from multiple hours down to 15-20 minutes is now essential, EV owners are no longer just the early adopters who enjoy a challenge, EVs are now being purchased by Australians that require the best possible experience from day one.

So where to place the chargers with regards to spacing? By good fortune this is fairly easy if all the locations get on board EV charging, the average distance between charge locations is 182kms with largest gap being 241kms on the Balladonia-Cocklebiddy leg a road that is reasonably flat and easy on driving range. Of the 14 most versatile charging locations only 4 are privately operated off grid sites, the remaining 10 are gazetted towns, the amount of electricity available at each site is a relevant but separate issue that you can read about here, chargers need to be placed where there are toilets, water and shelter.

There are two obvious exclusions from this list, one is the mid-sized coastal town of Ceduna, on that section of road Penong and Poochera have more useful spacing, no doubt Ceduna will get DC charging as some stage. The second location is Border Village 12kms from Eucla, despite being more active with tourists Border Village has a privately operated and at this stage very weak electricity supply compared to Eucla. I wouldn’t rule Border Village out as eventually competition will see both locations having DC chargers. You will note I have included both Mundrabilla RH and Eucla, which only has a gap of 65kms. Unfortunately this is only alternative without having a gap of at least 262kms, it’s also the section of road that has consistently strong winds.

How powerful would the Chargers need to be? From a marketing exercise 350kw would appear to be the first choice, drivers looking to switch from petrol to electric often still have the mindset that 5 minute refills are essential, in theory a 350kw charger could provide 182kms of range in 6 minutes, in reality very few drivers will need it. Personally I see 150kw chargers as being the better choice for at least a few years, 150kw would provide 182kms of range in approximately 15 minutes, to me that’s a far better use of equipment while barely adding much time to the overall trip.

To summarize: installing DC chargers across the Nullarbor is nowhere near the impossible task many believe it to be, it’s certainly a challenge but nothing like the challenge that has gone into building the roads and oil based fueling infrastructure already in place across this isolated part of Australia. Up until now it hasn’t been necessary as very few electric vehicle owners need to make the trip, but as electric transportation rapidly becomes mainstream in the same countries that build Australia’s car it’s now become a matter of urgency to change the mind sets and car buying habits of many Australians.

It often gets asked on social media forums and at electric vehicle displays why off grid EV charging is not being built. The answer is: it will be eventually, it’s not technology holding it up, nor lack of renewable energy available, it’s frequency although not in terms of electricity but in terms of traffic flow.

Many EV drivers are already charging at home from off grid electricity systems, this is cost effective because of two important points; firstly they’re sharing the power generation equipment with general household usage thus sharing the equipment cost; also they are only using around 20% of the vehicles battery per day, 50% at most, this means they can delay charging until excess electricity is available.

With home charging it really isn’t that difficult to install a suitable off grid electricity system without too much overbuild, for a commercial site on a country road it’s vastly different. The random nature of traffic flow makes sizing a suitable generation system without massively overbuilding very difficult. On an average day in 2022 a regional roadhouse may get 4 electric vehicles stop to charge, that is zero to one car some days and 10 cars on other days, add in long weekends and school holidays and the EV traffic flow could be far higher. It’s not too difficult to install enough chargers for the busiest day but having enough electricity production and storage to charge those EVs would require a generation and storage system that would spend the best part of a week completely under utilized, it’s near impossible to make a business case from that.

Here is a very rough example to show why: On the busiest day 16 EVs stop to charge over a 24 hour period, if each EV consumes an average of 45kWh including charging losses, to provide 720kWh would require a minimum of 180kw of solar panels with the smallest battery set up of approximately 600kWh, and there sits the first issue. Batteries are currently too expensive to be only partly used 5 or 6 days per week, solar is cheap but having such a large solar array that’s producing vast amounts of unused power for most of the week is a waste of resources.

• 1. Battery prices need to fall significantly: this is not as big an ask as it seems as off grid batteries don’t have to be Lithium based, off grid locations have no shortage of room, energy density is not important, the best battery is one that provides the best cost per kWh over its guaranteed lifetime in an often harsh environment.
• 2. One electricity generation system for everything: a shared off grid system is better value for money, but not only a shared system but a smart system where power consumption is carefully managed during busy time periods, water desalination and hot water systems can operate at times of low demand.
• 3. Charging cost: EV owners will openly say they have no problem paying 45 cents a kWh in country areas but make it 60 cents at peak times and 30 cents when excess power is available and charging habits will change, most Australian drivers are already accustomed to being fleeced by fuel companies on long weekends at least this way they have a chance at cheaper energy.
• 4. More electric vehicles need to be purchased in Australia: the bigger the flow of traffic in country areas the better the business case for building off grid charging facilities.

What is the short term solution?

A hybrid system of renewables and Diesel: as much as I dislike Diesel being used in passenger cars and pretend 4 wheel drives that never leave the suburbs it still has its place in country areas for another decade. Having a Diesel back up that covers the very busy days but only produces 10-15% of the overall electricity is a far better solution than the one Australia currently has. Most off grid roadhouses are powered close to 100% by fossil fuel (some have a few dozen solar panels) fueling up 99% of the vehicles that stop in with fossil fuels, a step in the right direction is better than no step at all.

The first option is to try and avoid using an extension cord, longer cords have a significant voltage drop when charging from single phase, on an overnight charge that could result in 15 to 20kms less range in the same charging time. This voltage drop also means unnecessary heat in the cable that could shorten it’s useful life. The other issue in using an extension cable is it’s highly likely to add another tripping hazard unless it’s used wisely. As much as possible avoid using a 25 metre cable to cover a less than 5 metre span.

Happy motoring.