Don’t blame EVs for power cuts

EV charging is not the cause of power cuts like those affecting the North Island this week, attributed by Transpower to insufficient power generation to meet demand.

Social media is awash with comments around the cuts, several blaming EV charging while one suggests no responsible EV owner would charge their car at peak hours on winter evenings apart from exceptional circumstances, instead taking advantage of cheaper late-night rates.

Others say the cuts are fuelling anti-EV sentiment.

Drive Electric chair Mark Gilbert says the power cuts are to do with the cold as people return home from work and turn on heaters and cookers.

Gilbert believes EVs’ vehicle-to-grid (V2G) capabilities and moves to solar power and battery energy storage may help alleviate such situations in the future – “but not this year or probably even the next”.

In the Waikato, WEL Networks posted on August 9: “Due to insufficient generation to meet New Zealand’s load demands, we’ve been instructed by Transpower (the national grid operator) to reduce the amount of load on our network with immediate effect.

“As a result of this there will be rolling power outages across the region. It is unclear how long these outages will be required for, however it is expected that this will not impact individual customers for more than a four hour period.”

TransNet NZ e-mobility division manager Glenn Inkster says it’s understandable people relate power cuts to the added electrical load of charging EVs, “but there are some other considerations”.  

The battery sizes in modern EVs store significant amounts of energy compared to what a home will use which gives a large ‘window’ for charging, he explains. 

“Set up correctly, EV charging should add no extra load to a maximum demand period like what we had on Monday night.

“In time, the EVs become a destination for excess renewable generation, effectively enabling more renewable energy to be available when needed for the national grid.”

Then an EV’s battery capacity will become a valuable asset for the likes of Transpower to utilise when required, Inkster says. 

“A small amount of power from an EV battery is a large amount for homes.

“One thing it (the power supply issue) does highlight is the importance of developing a smart charging network that can be controlled.”

Asked for a comparison between heater use and EV charging, Inkster says a standard 2kW home heater will draw 10 amps while the best EV charging is variable from 6amps to 32amps which should happen outside of peak demand times.   

The New Zealand Electricity Authority is reviewing the power cut event.