EV batteries are fit to run a home or even power the grid – but some car brands say 'no'

Australia Broadcast Center

11 hours ago

Richard Chapman likes to joke that his claim to fame was being treated to a cup of tea by James May, one of the trio of presenters on the hit former British motoring show Top Gear.
It's a sign of his tastes.
The English expat, who now calls the historic port city of Fremantle in Western Australia home, is a car nut — a self-described "petrol head".
"I've absolutely adored cars ever since I knew what a car was," Chapman says.
While that love has always extended to muscle cars, Chapman does not discriminate.
These days, it equally applies to electric vehicles, or EVs.
Richard Chapman knows the future of cars is electric. ( ABC News: Daniel Mercer )
"They're just incredible cars," he explains.
"And for me, being a petrol head ever since I was a child, I never thought I'd quite embrace the EV thing so fully."
Soaking up all the solar
But embrace it he has.
In fact, the rail signals and communications engineer has three EVs.
Chapman uses power from the solar panels on his roof to charge the cars in the middle of the day.
What his solar panels can't charge, he does with dirt-cheap electricity he buys from the grid during daylight hours.
"We get ultra cheap power from 9am to 3pm because there's so much excess solar on the grid," he says.
"So what we do is we just go hard from nine to three every day.
"Whichever one of the three cars needs a charge, I'll just pull that in the garage and then that'll give a bit of a blast."
Ideally, Chapman would like to take some of the energy stored in his cars' batteries to power his home in the evening, when his solar panels have stopped producing for the day and buying from the grid costs a relative fortune.
Compared with most people, he's lucky — he has a couple of batteries mounted to the wall of his garage to store excess power for the evening periods.
But he says that's not always enough.
"When it's in the depths of winter and it's when the peak of summer, either we're using the heating or we're using the cooling overnight, that's when we run out of power in the (batteries)," he notes.
"What I would really like to do is … draw off of the electric vehicles that have got hundreds of kilowatt hours sitting there."
Massive battery on wheels
Indeed, the batteries in most EVs are enormous compared with the size of the average household system.
Whereas a typical household battery has a capacity of 10 kilowatt hours, many popular EVs have batteries that can hold up to 50kWh, 60kWh, or even 70kWh.
It is enough energy, Chapman notes, to run an average household for days at a time.
There's just one problem.
His car is a Tesla, and it's not designed to pull power back out from the battery. There are many EVs for sale that can feed power out, but currently, the only Tesla that has the hardware to do this is the Cybertruck.
There are ways to use third-party equipment to get around this on a Tesla, but Chapman says doing this would void the warranty of a car worth more than $100,000.
Tesla currently does not support bidirectional charging. ( ABC News: Daniel Mercer )
"Tesla are very reluctant to have you do that, at least on the cars that they currently sell in Australia," he says.
At issue is a little-known technology that some say has big potential — so big, in fact, they believe it could help cut Australia's dependence on fossil fuels.
It's called a few different names, including bidirectional charging, two-way charging, vehicle-to-grid and many others.
Being able to tap into EV battery storage could fundamentally change — and benefit — the electricity system. ( ABC News: Alex Lim )
Ultimately, it boils down to a simple proposition — not only charging EVs so they can be driven around, but discharging them, too.
Ross De Rango used to run energy and infrastructure at the Electric Vehicle Council, an industry body, and now works as a consultant in the sector.
De Rango says there's a "big golden pot at the end of the rainbow" if Australia can make bidirectional charging work.
"If we have a couple of million cars that are able to export to the grid at peak time … the amount of power that that makes available … will mean that we can do things like close down coal-fired power stations," De Rango says.
According to De Rango, the different names ascribed to bidirectional charging reflect the fact it's not a single technology or application, but many.
He says the uses range from relatively low value and easy to much more technically difficult but valuable.
In its most basic form, he says it amounts to using an EV battery to power appliances and devices — what's known as vehicle-to-load.
Vehicle-to-load (V2L)
"It's simply using your car to run things like power tools from a power outlet in the car," he explains.
This technology, he says, is already broadly available in Australia, and all that's needed is a common extension cord and V2L adaptor fitted to the external charge port if the car does not have a built-in outlet.
Vehicle-to-home (V2H)
At a higher level, De Rango says EVs have the potential — and the energy — to help run a household through what's known vehicle-to-home.
It means using the battery in the car like a household battery. While the car is plugged in, it can either be charged — or charging the house.
For one, the EV needs to be designed to pull power back out from the battery.
"Lots of electric vehicles in the market have that today," he says.
"If what you want to do is run your home from the car without exporting to the grid, then obviously you need that electricity supply to be sized appropriately and the car-maker needs to be happy for you to do that."
Bidirectional chargers convert the DC power electric cars run on to AC power used in power outlets, but they don't come cheap, costing several thousand dollars.
Using EVs to power homes is still a fledgling technology, De Rango notes, and faces a range of requirements that are imposed on the householder.
But he says there is evidence some people are already using it, including during blackouts.
Vehicle-to-grid (V2G)
Finally, De Rango says there's the biggest potential application of all — so-called vehicle-to-grid technology.
As the name suggests, it would involve motorists providing the energy from their cars' batteries to the grid at times when it was needed most — typically during the evening peak.
A mix of hardware, software, and regulatory permissions is required to turn the energy from a car battery that's already hooked up to the home into the grid when required.
De Rango notes there are about 15 million cars on Australia's roads at the moment.
Although only a fraction of these are currently electric, he says this is bound to change markedly in the years ahead.
Eventually, he says, there will be millions of them.
If they all discharged into the grid at times when renewable sources wind down and gas and coal fill the gap, such as the evening, they could drastically reduce Australia's need for these fuels.
Being able to tap into that combined energy storage could fundamentally change — and benefit — the electricity system, De Rango says.
"It's going to be a huge step towards enabling us to no longer be burning things in order to produce electricity," he says.
Crucially, De Rango argues that motorists will need to be properly rewarded before they agree to use their car's battery to help prop up the grid.
Removing roadblocks
On that front, he says governments will need to take the reins and corral automakers and poles-and-wires network companies into a position of support.
"Government support will make the difference between it being adopted by the early adopters … and it being the case that hundreds of thousands, millions of people can do it in relatively short order," he argues.
Electric vehicle expert Ross De Rango. ( ABC News: Ben Knight )
Federal Climate Change and Energy Minister Chris Bowen backs bidirectional charging and is calling on car makers to do likewise.
The minister says the government is trying to smooth the way for the technology.
For example, he says it has approved standards, including for vehicle-to-grid charging.
He put sceptical automakers on notice, saying consumers would increasingly vote with their feet.
"I certainly encourage car manufacturers to get with the program," Bowen says.
"Consumers will want this.
"As consumers hear more and more about it, they'll see the advantages.
"And increasingly, when consumers go to the car yard or check online to pick their next car, they'll be looking at EV options, and they'll look at which EVs give them the capacity to reverse charge."
For his part, De Rango acknowledges the disconnect between the promise of two-way charging and the reality so far.
He says it's true some car brands — led by Tesla — are wary of the technology.
"It's not so much a technical impediment, it's more a question for Tesla from a corporate standpoint," De Rango says.
"I would note that it is reasonable for an individual car maker to set conditions around that.
"After all, they are the ones that own the risk of the warranty on these vehicles for a period of time."
Tesla, not only a leading electric car brand, also sells household batteries. ( ABC News: Daniel Mercer )
De Rango also notes a growing number of car makers are getting on board and many of those are starting to challenge Tesla's traditional dominance of the EV market.
Still, he says the potential benefits of bidirectional charging are too great to squander.
"The opportunity is the earlier closure of coal and gas-fired power stations," he says.
"The risk of absence of support for this technology is that those benefits will take many more years to materialise."
Tesla was contacted for comment.
Fremantle EV owner Richard Chapman, for one, is impatient for the change.
He personally suspects brands that oppose bidirectional charging will be on the wrong side of a bet with consumers.
Richard Chapman sees a future for EVs beyond their traditional use. ( ABC News: Daniel Mercer )
And he describes as "frustrating" the inability to capitalise on the significant amounts of electricity stored in his cars' batteries.
Most of the energy that is typically stored in his EVs is generated by renewable sources.
Chapman says it would be the same writ large as ever more electric cars soak up excess wind and solar generated by Australia's electricity system.
"The key thing that's missing right now is battery storage," Chapman says.
"And that is what we have now with EVs.
"We've got all this battery storage around, all in our suburbs.
"What we need to do is tap into that because we've got all of this solar."