New report reveals mass shift to electric cars could cause ‘capacity issues’

A new energy report has revealed a mass shift to electric cars could “present an issue” for the nation’s power grid if not managed correctly with concerns hot spots will occur from places such as public carparks, highway chargers.

• Around the world in 3 years in an electric car
• Labor’s emission standards a ‘carbon tax on cars’

As few as 100 electric cars charging in a suburban street could overload the local street transformer, an Australian report into the power demands of such cars reveals.

A Shorten Government plans to massively increase the number of electric cars in Australia, but the new energy report shows the nation’s power grid will struggle to cope.

“If they are not managed correctly, hot spots could present an issue for utilities,” the report from Evenergi, a start up company promoting electric cars, says.

Bill Shorten during the launch of Labor's Climate Change Action Plan. Picture Kym Smith

MORE NEWS

Cake, birthday invites banned at Sydney public schools

Silverwater jail inmate charged with murder of cellmate

‘Heartless’ Liberal voters targeted in bid to oust Abbott

Report author Dan Hilson said if there was a density of plug in electric cars within a small geographic location then “residential charging will become an issue”.

The Managing the Impacts of Renewably Powered Electric Vehicles on Electricity Distribution Networks report calculated how much impact the charging would have on the power grid.

“Clustering of a relatively limited number of high power chargers that have high utilisation can result in a hotspot,” it found.

“In the time horizon of 2020 to 2025 considered in this report, there is potential for capacity issues in the network.

“In Evenergi’s view, the greatest risk for hot spots will occur from public carparks, highway chargers, pool vehicles, bus fleets and clusters of multiple use cases in a localised area.”

The modelling shows that a street transformer of a typical size of 50-250 kVA, would “exceed capacity” if 100 plug in electric cars using a 7.4 kW charger were going at the same time.

Even just 10 cars could lead to 30 to 150 per cent of the capacity of the transformer.

The Actewagl Electric Car Charging Station in Canberra. Picture: Mick Tsikas

And if a 1000 were charging, the load could exceed the capacity of the local feeder.

Even a load drain of just 10 per cent from electric cars on the grid could “could result in plug in electric vehicle charging hotspot and a capacity constraints”.

In the US, problems have arisen with supplying enough power. A study commissioned by the Sacramento Municipal Utility District estimated 17 per cent of the energy utility’s transformers may need to be replaced due to electric car related impacts by 2030, at a cost of $10,411 per transformer.

Another study in the UK found that thirty two per cent of low voltage feeders will need intervention when 40 to 70 per cent of customers have an electric car and charge at home with a 3.5kW charger.

“Without proper management, load from as little as 10 per cent from plug in electric vehicles (PEV) charging on a given grid asset could result in PEV charging hotspot and a capacity constraints,” the Evenergi report says.

Mr Hilson also points out that street charging and rapid charging “will need to become widespread” to encourage people who do not have off-street parking at home to buy the cars.

Today, in a statement, Mr Hilson defended the “positive potential” of a mass shift to electric cars.

“By encouraging EV charging at times when there is surplus energy and limiting the amount of charging during times of peak demand we can potentially create a more efficient, balanced, and flexible grid,” he said.

“Evening out demand would unlock more value from existing power network assets. If managed correctly, this would ultimately lower costs for consumers.

“EVs do require significant power, but it’s important to recognise that people travel around 16 kilometres on their average commute. That means they would need to charge for just over an hour with a 7kW home charger. That charge could easily and conveniently be scheduled for an off-peak time in the middle of the night.

“The main problem power networks face at the moment are the huge peaks in demand, most notably by air conditioners on very hot days. EVs do not create the same challenge, and may actually help power networks get more value from their assets.

“Furthermore, the mass uptake of EVs could also provide power networks with a giant collective battery, because EV batteries plugged into the network can be drawn upon during times of peak demand. This technology already exists and there are mechanisms through which consumers can be compensated for assisting the network.”

Originally published as New report reveals mass shift to electric cars could cause ‘capacity issues’