Cr Kate Wilson, chairwoman of the Dunedin City Council's infrastructure services and networks committee, raised the issue at a committee meeting recently.
Yesterday, she said there was a lack of information about the city's capacity to cope with the continuing uptake of EVs.
Dunedin already led the country in EV ownership, after a recent study identifying 500 owners of electric cars in the city.
And, with the Government now proposing financial incentives to encourage that uptake, Cr Wilson said the city needed to plan more strategically for the transition to EVs.
Parts of the city's electricity network were already known to lack capacity for growth, such as Middlemarch, but there was also not "a huge amount of information coming back from Aurora about where there is capacity", she said.
The city needed to ensure the network had capacity for more fast-charging stations, particularly for use by commercial vehicles, and that it could accommodate more people wanting to charge their vehicles at home at night.
"If 50% of our cars were EVs, and 20% of those needed fast-charging, where is that capacity to do that in the most sensible way?
"Do we have that capacity in the industrial areas? I don't know, and I think we should know that before we are saying we can do this."
The transport sector was "a huge part" of the city's carbon footprint and offered significant potential for reducing greenhouse gas emissions, to help the city meet its carbon net-zero goal by 2030.
Cr Mike Lord has already raised concerns the goal could come at a huge cost, more than $150million across one major council department and double that across the rest of the organisation.
Cr Wilson said yesterday the provision of adequate electricity infrastructure for EVs was just one example of those costs.
But the cost of becoming carbon-neutral needed to be tackled, and delays now would only add to the bill later, she said.
Good planning, on the other hand, would help minimise the costs involved, she said.
"Energy is going to cost us. I think every indicator is the cost is going to go up for energy. So the more energy we can spend getting ourselves future-proofed for that now, the better, really."
Aurora asset management and planning general manager Glenn Coates told the ODT the city's electricity network was adequate for existing demand, and work was already under way on longer-term investment plans.
That would include electric vehicle forecasting as part of wider long-term planning for the network, but expectations were that the impact of EVs on the network over the next three years would be "small", he said.
"We believe the network impact of electric vehicles is dependant on the charging behaviour of the community. For example, if people are charging their electric vehicles at night the impact on the network will be less."
The company had also partnered with ChargeNet to support the installation of new public fast-charging stations in Dunedin and Otago.
Three were now connected to Aurora's network in Dunedin, seven more elsewhere in Otago, and more were planned, he said.
DCC energy plan co-ordinator Jeremy Baker said the rise of electric vehicles was expected to "continue, if not accelerate".
That growth would place extra demands on the network, but the uptake of EVs would also present opportunities, including the rise of "vehicle-to-grid" technology, allowing vehicle batteries to be used as a source of stored electricity during peak times.
