Future EVs may stress network capacity

“As battery technology costs continue to fall, car battery sizes increase, and customer demand for longer-range EVs grow, the current model of public charging stations cannot be assumed to be the default charging infrastructure of choice beyond early adopters,” says the report. “Vector is seeing clear trends of longer range vehicles, requiring larger capacity batteries, and customer behaviour that suggests a trend towards faster charging times and clustering of chargers in some areas on the network. These trends necessitate the need for a strategy on EV charging for New Zealand that is future-proof.” “Left unaddressed, tipping points for significant network upgrade investment can be expected to have either large cost implications for consumers or eventuate in physical constraints preventing customers from charging their EVs at home.” Consumer's views on EVs Vector found that EVs are perceived positively in New Zealand - a recent customer survey found that 60 per cent of New Zealanders would consider buying an EV, as opposed to 54 per cent in the UK. This high interest is distributed evenly throughout the country and across all demographic groups. The number of EVs on NZ roads is currently low (6,884 EVs were registered in February), but uptake is expected to increase exponentially, achieving the government target of 64 000 EVs (2 per cent of current car fleet) by 2021, or even more if the current growth rate continues. Uncertainty around EV range Currently 92 per cent of EVs in Auckland have battery capacities between 10kWh and 30kWh, which corresponds to an electric range of roughly 50 to 150 km. However, in the next couple of years, the market share of EVs with longer electric ranges is expected to grow, with new EV models having an average range of 350-500km. “Larger batteries take longer to charge and might even make over-night charging practically unfeasible unless faster charging technologies are adopted,” says the report. Vector has assessed the capability of the existing network to accommodate EVs based on different penetration rates, battery sizes, charging capacities and across different part of the day. “The analysis highlights that the connection of fast and rapid chargers will stress or surpass the network capacity even at penetrations as low as 10 per cent.” The report concludes that effective electricity network integration will be the foundation for successful EV uptake. “In order to ensure customer choice and support EV uptake in NZ, future network investment and integration risks need to be considered today while taking into account technical, regulatory, affordability and societal implications.” Click here to read the full report.