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Off-peak vehicle charging is the way to go, not only because it saves EV drivers money, but also to make sure New Zealand’s electricity supply can cope with ever-increasing demand.
That was the message from Vector at a Rodney Local Board workshop last week during an update on regional infrastructure and supply.
Communications manager Matt Britton said that while there was no problem at the moment, the increase in EVs was something Vector needed to keep a close eye on, as the power used to charge two vehicles was around the same used by an average house.
“Not only is it more demand, but it’s at the wrong time,” he said. “If you’re out during the day and you come home in the evening and turn on the heating, start cooking dinner and plug in your EV, then that’s just adding to peak demand.”
He said Vector was monitoring the growth of EV use and its impact on the power network across Auckland and beyond, using EV tracker equipment to analyse where charging was taking place and to help it avoid “clustering impacts”.
Members heard that uptake varied dramatically by suburb and according to socio-economic levels – as an example, although both have similar population levels, Remuera had 1187 EVs and Otara just 45.
Vector wants to use technology to shift the system load around by staggering charging times.
“So if 100 people plugged in their cars at six o’clock, only one of them would actually start charging then, they would just be staggered over time,” he said.
The government’s Energy Efficiency & Conservation Authority agreed that managing demand for charging was key to ensuring the electricity network could cope, using off-peak charging at home or dynamically managed public chargers that could adjust power to distribute electricity more evenly.
Vector operations and engineering manager Marko Simunac added that if drivers charged their vehicles outside peak hours, say at 9pm instead of 7pm, it would also be cheaper for them, as well as taking load off.
Vector has already achieved something similar with Auckland Transport (AT) and its burgeoning electric bus fleet.
AT has doubled the number of its zero emission electric buses to 180 in the past year and has been working with Vector to make sure the considerable charging load for them – and the cost – is spread.
“We’ve worked with AT over the past couple of years to provide infrastructure for its electric buses and we’ve worked out a contract backed up by technology so they get cheaper rates to charge in off-peak,” Britton said.
“So they’re incentivised and enabled through technology to make sure the buses are charged when they need to be, but at off-peak times. That works out for us and for them.”
Board member Guy Wishart said it should be more of a two-way street for car drivers, by using EVs as mobile battery storage to power homes, something that can now be done with many EV batteries.
“It would make enormous sense for Rodney – you could go off-site, get powered up, come back and power your whole home with this massive battery you’re carting around in a car,” he said.
Community engagement manager Teina, Teariki Mana said that had already been trialled in Piha, but it wasn’t feasible because of the distance from other charging points.
“So during any outages, you had to drive your vehicle out to charge at a different point, and it wasn’t sustainable,” she said. “But there was lots of learning in terms of what can happen.”
