NRMA totally rebuilds “world-first” off-grid EV fast charger, and it appears to be working fine

Motoring group NRMA has totally rebuilt the landmark off-grid EV fast charger in the Northern Territory, and it appears to be working fine, in contrast to the troubled original version that eventually had to be scrapped.

The fast-charger at Erldunda, on the Stuart Highway between Alice Springs and the South Australian border, was branded a world first when it opened in October, 2023, and a trailblazing part of its National EV charging network, partly funded by the federal government.

But the facility was plagued with problems – delivering slow charging, if it worked at all, and was the source frustration for EV drivers intrepid enough to get there. (They often had to wait and “trickle” charge with the wall mounted chargers at the neighbouring petrol station).

Rob Dean documented some of the issues from a driver’s point of view here. See: A tale of two remote off-grid EV fast chargers: The wondering and the woeful

The Erldunda site has now been relaunched, and all the equipment has been changed. It even has a new 26 kW solar array mounted on the canopy (well one panel had to salvaged from the previous mounting because of a damaged module in transit), as well as 200 kWh of battery storage, and a new control system.

Front and centre – and most visible to the customers – are two new 80 kW DC fast chargers provided by Sinexcel, replacing the previous chargers supplied by Tritium.

Comments by users on Plug Share indicate that most – although not all – customers have used the facility with no problem since the reopening, and at or close to the advertised speed, although they do now have to pay 99c/kWh to charge. The previous version was free.

“In the five weeks since re-opening, the charger has provided repeated high speed charging sessions with the vast majority of energy coming from BESS (the battery),” an NRMA spokesperson told The Driven in an emailed statement.

“The system now correctly responds when there is low power available due to high use across plugs or low solar availability.” If the battery is exhausted, then there is a diesel back up generator, but only if necessary.

Andrew Simpson, the former head of engineering at NRMA who worked on the original project, has written an interesting post on LinkedIn about the experience and learnings with the first generation technology.

“There were significant political and commercial imperatives to deliver this first standalone prototype very quickly, and our acquisition, engineering, deployment and operations teams had to embrace a tough challenge,” he writes.

“There were no precedents in the global public domain for such a system, and so we did what desktop research we could prior to passing “GO!”, but from tender to touchdown was a period only measured in a few short months, and just in time for a showcase in partnership with the 2023 Bridgestone World Solar Challenge.”

Simpson writes that at peak periods the installation did manage to deliver 2 x 35kW charging operation, although reverting to 1 x 35kW charging on diesel backup only.

“There were also a bunch of other operational and maintenance challenges that I won’t go into any further here, apart from saying our industry can only benefit from a continuing focus on more remote public charging locations with bespoke power supplies that are far more challenging to operate and support.”

Of all the equipment, Simpson said the solar canopy was the only part that worked as planned, although it is not clear why it was replaced in the new version.

Simpson noted the “undue sensitivity” to power quality of the fast charging equipment, the unexpected challenges in battery integration and output performance that limited the system’s operating envelope and stability, especially when transitioning to the genset that unexpectedly became so entangled given other constraints, and the challenge of poor comms.

“It was always clear our initial timeline didn’t allow much time for validation, but with hindsight we unexpectedly carried more risks into the field than had been anticipated, and no amount of prior testing in the lab or factory could have revealed all,” he writes.

“We of course found all of this out the hard way in the field notwithstanding the significant political and commercial imperatives to give it a try. I am pleased that more time has since been taken with the 2nd and 3rd standalone units, but the broader management of expectations could have been different at the time.”

Still, he says the experience will serve the industry well.

“At the time we never tried to claim it was optimal… it was the first of many such systems expected under this program and others, so I look forward to seeing other investors taking their own risks to do it better too.

“As the Government is presently reviewing its national Minimum Operating Standards for Government-supported Public Electric Vehicle Charging Infrastructure, it’s an ideal time for our industry to be having an open conversation about how to provide equitable access to adequate public charging coverage, capacity, uptime and pricing in such challenging locations.”