Queensland network plan to look at EV rooftop solar charging problem

The problem of not being able to use rooftop solar to supply an electric vehicle (EV) fast charger in Queensland is not part of the latest Network Electric Vehicles Tactical Plan, but it may kick the issue forward.

The latest network EV plan by state-owned Energex and Ergon outlines 13 tactics to engage with EV owners, get better visibility over charging infrastructure, and figure out the knotty problem of connection issues.

Tactics 6 and 9, which delve into understanding customer charging needs and look at how to evolve charging infrastructure, will coordinate changes needed to give EV owners access to their rooftop solar.

The technical detail, however, comes under the purview of the Queensland Electricity Connection Manual, due out for public consultation soon, says Energy Queensland principal adviser for strategy and innovation Dean Comber.

The network plan wants to encourage Queenslanders to engage with smart meters and chargers in order to share data with the networks and energy companies — so they know where major power draws may be coming from — and to encourage EV owners to charge at off-peak periods.

But as reported by RenewEconomy, the technical restriction on home fast chargers means Queenslanders are likely to be opting out of smart chargers and meters in order to access their rooftop solar for their EVs using a ‘dumb’ 20 amp, 4.6 kW wall chargers.

The plan commits to working on EV connection standards, which includes developing dynamic operating envelope technical standards for solar-charged EVs and working with other entities to create some consistency in EV charging rules.

And it plans to research how to integrate metering, solar PV, batteries, home energy management systems, and those dynamic operating envelope signals to encourage EV owners out of charging during peak periods rather than using technical restrictions to prevent them.

Furthermore, the network plan is calling for research into how to manage vehicle-to-grid charging, ahead of an expected surge of vehicles entering Australia with that capability.

"As at April 2023, around 5 per cent of EVs in Queensland had V2G capability, with the percentage declining from a peak of 13 per cent in early 2021," the report said.

"With few of the promoted EV releases in 2023 having V2G capability, we expect that market share to fall further, before rising, potentially dramatically, as more EV manufacturers offer V2G capability."

Already Queensland is dealing with demand from a range of sectors, as the number of electric motorcycles, plug-in hybrid and battery passenger cars and trucks, and electric buses rose from 3900 in June 2020 to 23,000 in April 2023 — and that number is only being constrained by a lack of supply in passenger cars.

Furthermore, Ergon's and Energex's own EV SmartCharge Queensland Insights report showed more than three quarters of 197 EV owners surveyed had rooftop solar and 19 per cent also had a battery.

There is currently no legalisation forcing EV owners to apply to have a charger at home or tell their network, creating a risk of invisible load suddenly appearing in the event of "a distribution transformer fails or quality of supply issues arise due to EV charging".

The network plan is continuing to develop an EV charging detection model that uses smart metre data to locate properties where EV chargers are likely to be used

"The first output revealed thousands of residential locations where the model is confident that EV charging has taken place recently," the report said.

"This will allow us to identify EV clusters on individual transformers and analyse transformer data to detect early EV charging impacts on the grid."

Rachel Williamson is a science and business journalist, who focuses on climate change-related health and environmental issues.