Bi-directional charging to disrupt two industries

NISSAN and Jet Charge are counting on bi-directional charging to spark a revolution in the automotive and energy industries, with the second-generation Leaf small hatch the first series-production full-electric vehicle to support the innovative vehicle-to-grid (V2G) technology.

As reported, bi-directional charging allows Leaf owners to use their vehicle’s battery pack to help power their houses or buildings when desired, sending energy back to into the electricity grid that in turn can be used to power a house or building.

The key advantage of this set-up is the ability to charge the Leaf at off-peak electricity rates and then feed excess power back into the house or building's inverter for use during peak periods.

Alternatively, renewable energy can be captured from sources such as solar panels during the day.

Speaking to journalists this week at the Leaf national media launch in Melbourne, Nissan Motor Corporation global director of electric vehicles Nic Thomas said that if bi-directional charging is taken advantage of during peak periods, electricity companies may not need to build additional power stations to cope with growing demand.

“Just draw some of that energy out of the cars, you can do that at home, or you can do it in a building, or you can do it at grid level. All of it is possible,” he said.

“We build cars with batteries in them … so we’re reducing the resource consumption, we’re making the energy grid more efficient, we’re earning customers money, we’re making everybody happy, we’re achieving emissions targets, all in one.

“This is not fantasy. This is not something we’re dreaming of doing in the future. It’s what we’re doing now.”

Mr Thomas stressed that the new Leaf “we sell today has all of the capability it needs” for bi-directional charging, although there is one big catch: the supporting hardware is not available in Australia yet.

“You need to buy that (bi-directional) charger, which is roughly the same size as a normal AC wallbox, possibly slightly bigger, (and) a bit more expensive,” he said.

While different levels of bi-directional chargers are available globally, Leaf customers are expected to opt for the version that can draw up to 10kWh from its 40kWh lithium-ion battery, which Mr Thomas said is more than enough to power the average household that uses 6kWh on average during peak periods.

“You’ve still got all the energy you need if you need to make that emergency trip … in the evening time … and you can top up again on a very cheap overnight tariff,” he said.

“In the morning, you use 10 per cent (of the battery’s charge) for the breakfast-time power surge and then you drive off to the office and you’ve got all the energy you need stored in the car.”

Nissan Australia national manager of electrification and mobility Ben Warren said that while bi-directional charging is not actually possible in Australia at the moment, it is expected that the supporting hardware will go on sale “within 12 months”.

“It’s starting to make its way into the world in other markets,” he said. “Charging manufacturers are really commercialising it and gearing up now.

“Part of the task for us is getting some prototype units and what’s been out there in the world and testing them in local conditions for standards approval.”

Current V2G trial markets include the US, the UK and Denmark, while the Asia-Pacific region will be the next cab off the rank, with applications at both house and building levels.

Jet Charge chief executive Tim Washington added that Jet Charge will bring its own V2G hardware into Australia during the second half of this year, with a view to test and certify it before its general release, although it is not expected to be cheap.

“We’re essentially going to be running our warehouse from the Leaf,” he said. “In terms of how much it costs, I don’t have final figures, but all I’ll say is it costs less than it does to put a stationary storage battery in your house.

“If you look at some of the stationary storage products, there’s a really popular one (Tesla’s Powerwall). It’s 14kWh and it costs you about $14,000, before installation.

“That (Leaf) has 40kWh and to get the power out of that is going to cost you less than a battery you currently buy for your house.

“This is not sci-fi. It’s going to happen this year.”

Mr Washington added that “cars are going to be energy assets first, mobility assets second” thanks to the advent of bi-directional charging.

“One of the criticisms levelled at cars is what do they when they’re parked? They’re silly assets, right? But if you can utilise that car to power various things and use it as a mobile battery, then it becomes an energy asset most of the time,” he said.

“We think bi-directional charging – and this is why we’re so excited about the Leaf – will spell the end of residential stationary storage … (and) we think it will challenge our assumptions on the future of personal-owned transport.

“Right now, most of the predictions about how none of us will own cars anymore are all built on this assumption that cars are inefficient assets, but what if they were one of the most efficient assets that you have?”

Mr Washington concluded that bi-directional charging “will make EVs one of the largest generators on the grid”, capable of replacing all of the generators that currently provide power.

“When I talk to fleet managers, I say, ‘You can genuinely become a revenue centre rather than a cost centre for your business, or at the very least, you can have a net-zero cost’,” he said.

“This changes everything because you’re able to take electricity out of the car.”