Off-grid EV fast charging stations start to take shape in outback Australia

Good progress is being made on the provision of DC charging networks in more remote parts of Australia away from the main grids.

The lack of major settlements on main routes, sparse population and long distances all present major challenges which are less common in the more populous eastern states.  Some innovative solutions have been found, such as the now well-known biofuelled charger at Caiguna that can run on chip oil, but more mainstream solutions are needed for the rest of the country.

The challenges in providing fast-charging facilities in off-grid areas are many – apart from the distance travelled to deliver and maintain the equipment, there is also the question about how to power the facilities and ensure reliability.

Horizon Power, which is responsible for the power supply outside of Western Australia’s main grid, known as the South-West Interconnected System, is currently preparing the design for its stand alone off-grid solutions which it plans to introduce at fourteen sites across the vast state.

I was fortunate to speak to Horizon project manager Dan Healy who told The Driven the first of the units are at the factory testing stage, with two units fully built and another seven currently in production. The units will be skid mounted kiosks with modular, scalable Tritium RTM 50 chargers and two CCS2 chargers with 6 metre cables.

Output will again be split 50:50 with both ports in use. Power comes from a 50-60kW ground mounted solar array feeding a 70-100kWh battery, with a 60KVA diesel generator as backup, able to provide 100% load during periods of low PV output.

The off grid system is sized to provide two EV charges, each of around 34kWh, or enough to travel 200km, before needing recharging from the solar PV or generator.

Some clever engineering has gone into load management to ensure that the charger ramps up at a slower rate to match the generator’s output and prevent tripping. This may be noticeable as a rise in charging speed over the first four minutes.

The off-grid units will be remotely monitored with a set maintenance regime, and all units will be serviced by local contractors across five regions. They will be on the Chargefox network and will be set to a free charging mode in the event of any communications failure.

Horizon Power’s remote network is on track to be completed by February 2024, apart from four sites near the WA/SA border which were additions to the original plan, but should still be completed by mid to late 2024.

The NRMA motoring organisations has also announced a trial of three types of first generation stand alone off-grid charging stations as part of its National Electric Highway project that is jointly funded by the Federal government.

More details will be available after commissioning, but the units will be containerised with solar, battery, diesel backup, Tritium chargers and up to four charging berths, each capable of delivering around 75kW, based on illustrations and prior information.

The CEO of NRMA Energy, Carly Irving-Dolan, says the program is designed to help fill the gaps in national charging infrastructure where there might be low use sites with little commercial interest. She says any duplication of chargers introduced redundancy in the event of failure of any network, plus future proofing for higher demand.

There could be some duplication as there are a limited number of suitable remote sites in WA, many of which are listed for chargers by both NRMA and Horizon Power.

This may introduce some constraints at sites with limited connection and capacity, but is still a tremendous boost to WA’s charging networks. Off-grid chargers avoid these constraints but at significantly higher cost.

Irving-Dolan says the NRMA also has some capacity to self fund additional chargers in gaps identified by states, and that the national network should be largely complete in 18-24 months.

Much of the complexity relates to difficulties with grid capacity as well as negotiations with site hosts and land owners. There is some history in WA that occasionally site owners have required a fair bit of convincing about the potential financial benefits of hosting a charger!

Further afield on the South Australian part of the main road route to WA (Eyre Highway), fast DC chargers will be installed by NRMA as part of the National network, complemented by RAA DC chargers as far west as Ceduna.

Some may criticise the amount of duplication, but Irving-Dolan makes the point that by 2030 Australia will require 20-30,000 public DC chargers, based on a ratio of one per 100 cars – and the latest EV Council report identifies only 967 such chargers, with a current ratio of around 1:180 cars.

Bloomberg Green reports that Australia has crossed the key 5 per cent EV sales threshold (it is at more than 7 per cent so far in 2023) and that EVs will be 25 per cent of all new car sales within four years. Without forward planning like this we are likely to see queues, just like those that currently form at the diesel pumps at remote roadhouses.