Can the grid cope with electric cars?

Over a decade ago, an advanced powertrain specialist working for Toyota told carsales that the rise of the electric vehicle would unleash an Armageddon of sorts.

Bill Reinert predicted that neighbourhood brown-outs would occur with increasing frequency as more EVs were charged at the same time. Owners would arrive home at 6pm and immediately plug the car into the domestic power supply, en masse.

Plugging hundreds – or thousands – of EVs into the grid at the same time would require a lot of power in localised areas. Presumably Reinert was expecting fast-charging EVs at home to be the norm, as indeed it may well be one day.

For a start, we’re reluctant to buy EVs in the sort of numbers that would result in early-evening brown-outs.

In reality, this hypothetical scenario looks to be a long way off in Australia – if it ever eventuates.

That’s not to say the Australian government isn’t aware of the potential consequences, recently providing $1.6 million in funding towards a trial through the Australian Renewable Energy Agency (ARENA) where 176 homes in Victoria, Tasmania and the ACT will monitor the real-time impact of EV charging habits.

According to the federal minister for energy and emissions reduction, Angus Taylor, “an unmanaged uptake of EVs could have negative impacts on the electricity grid if a large number of vehicles are charged at home during peak periods”.

“This trial will give us a greater understanding of how to integrate future fuel technologies in Australia without compromising our energy grid,” he said.

In a 2020 parliamentary report on electric vehicles, it was noted by Infrastructure Australia that EVs will have “negligible impacts on grid consumption” over the next five years even if sales of battery-powered cars continue to trend upwards at the current rate.

However, Energy Networks Australia (ENA) – the peak national body representing gas and electricity suppliers – claimed that “Australia’s distribution networks were not designed for any significant uptake of electric vehicles and the consequential demand for charging”, suggesting a co-ordinated approach to EV charging habits was necessary in order to maintain a stable network and keeping costs down.

It indicated that incentives encouraging EV owners to charge only during off-peak periods would ensure the electricity grid could be adequately managed with the existing infrastructure.

The Australia Institute added in its submission to the report: “Co-ordinated charging would prevent [EV] charging from increasing the size of afternoon and evening peaks” and would “shift the charging periods overnight to ‘fill’ the demand ‘valley’, when electricity is cheaper”.

The Australian Energy Market Operator (AEMO) has already noted that the market for power from the grid has been ‘flattening’ in recent years due to the uptake of rooftop solar (photovoltaic) panels for over two million households around the nation.

The cost of sustainable power generation on an industrial scale is declining rapidly and is already cheaper than building new coal-fired power stations in Australia, let alone nuclear power plants.

But the problem is not sourcing the power; it’s distributing the power and balancing the load between peak and off-peak periods.

AEMO boss Audrey Zibelman has stated on record that the growth in rooftop solar power generation is equivalent to a new coal-fired power station entering operation each year – and the grid as it stands can’t handle the extra output.

Electric cars won’t necessarily worsen the situation, however. If the car remains parked in the garage on weekdays, it can be recharged from solar power to keep the home powered up during the evening. This could be through Vehicle-to-Grid (V2G) technology.

In the parliamentary report, Infrastructure Australia stated: “With the right frameworks in place, electric vehicles will be useful grid assets whose benefits will increase the more electric vehicles are adopted.

“EVs used in a smart network could be used as a short-term storage of excess, off-peak electricity generated from renewable sources that could flexibly be dispatched [to] counteract peak demand. They could also be used for local, residential consumption.”

Adding to that, TransGrid suggested that by 2040 Australia’s EV fleet could provide up to 350GWh of electricity storage – equivalent to the power provided by the proposed Snowy Hydro 2.0 project and enough to power approximately 500,000 homes during peak power periods.

Whatever happens, electric cars will become more prevalent in the future and how, when and where they are charged will have some impact on the electricity network.

But, if EV owners play their part, it’s not the Carmageddon that Reinert might have predicted.