Using your electric car to power your home

July 2022   By: Toby Hagon

That scenario may not be far away now that vehicle-to-grid (V2G) charging for electric vehicles is a reality.

Long talked about, the ability to use excess electricity in your EV’s battery to power your house or send excess back into the grid this year received the regulatory tick from the Federal Government.

V2G or vehicle-to-home (V2H) technology allows drivers to send energy back during peak times before recharging when electricity is cheaper.

Or you can power your house, potentially keeping the TV, fridge and air-conditioning working at night before recharging from rooftop solar panels the next day.

Tim Washington is the CEO of JET Charge, a company that installs hardware in homes and businesses for electric vehicle charging. He describes V2G and V2H as a “game changer” for EVs.

“It’ll be the first time we can use the car for something other than transport,” says Washington, referring to the 23 hours the average car is not used each day.

“It will act like a stationary storage battery.”

He says the potential is enormous, especially when it comes to utilising a costly depreciating asset.

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Sell your excess energy back to the grid

There’s potential to significantly reduce electricity bills for those turning to their car for power.

A car can act as an energy storage device and one with a lot more capacity than most dedicated home batteries such as the Tesla Powerwall.

“They don’t have to do anything special,” says Washington of consumers’ ability to use their car to store electricity. “Before you know it your next bill will be zero.”

EV Council CEO Behyad Jafari says there could also be the ability to make money from your car. He references a trial in Japan that allowed Nissan EV owners to park for free if they allow the carpark operator to have some of their excess electricity.

“If we get this right, we can make charging an electric vehicle free because you’d be selling your energy at the right time, charging it at the right time.”

Crucially, he also says there’s the potential to smooth the grid, something reinforced by a 2019 report prepared by Energeia for the Australian Energy Market Operator.

The report states: “Large battery storage capacity has the potential to be harnessed through emerging vehicle-to-grid (V2G) technology to provide customers with additional storage capabilities and assist the grid during peak demand events”.

Jafari says that will not only benefit EV owners but also those without EVs.

“The promise of it is it’ll increase the stability of the grid and also help to bring down the unit price of electricity, so it’ll make electricity prices cheaper,” he says.

You’ll need a bi-directional charger

As with anything new, there are tricks, and the enabling technology is not cheap. It’s not a matter of simply plugging your EV into a powerpoint or its usual charger.

You’ll need dedicated hardware that can regulate the flow of electricity and ensure it is charging or discharging at the right time for the vehicle owner and the grid operator.

For now, there’s only one bi-directional charger available in Australia, a unit called the Wallbox Quasar. It sells for about $10,000, which for many will be enough to shun the idea. But the CEO of JETCharge, which retails the Quasar, expects those prices to drop soon.

“I think it’ll come down in the next few years as more competition hits the market.”

Washington says big players in the electricity space such as ABB and Delta are working on V2G and V2H hardware options, something that could hit the Australian market as soon as next year.

Until then he believes it’ll be more of a niche technology, or “enthusiast grade product”, as he describes it.

Going off-grid a dream (for now)

If all this talk of powering your house from your car has you salivating at the thought of going off the grid, don’t get too excited just yet.

The Wallbox Quasar requires a grid connection to operate.

“It doesn’t operate in what we call ‘islanding’ mode,” says Washington, explaining that it requires a frequency from the grid to function.

For the same reason, your car will not be able to power your house in a blackout, for now at least.

“If there’s a blackout and there’s no grid connection it won’t work.”

All of which seems like a short-term issue.

In announcing its F-150 Lightning EV in the United States, Ford talked up the ability for the car to step in if the grid failed.

“With Ford Intelligent Backup Power and the Home Integration System, F-150 Lightning automatically kicks in to power your home if the grid goes down,” the company said in announcing the all-electric ute that sells from $US39,974.

With up to 131kWh of battery storage, the large ute could power the average Australian home for a week.

There are currently no plans to sell the Lightning locally, although there are more than a dozen electric utes currently under development with some slated for Australia. Many are planned to power external appliances or a house.

Most EVs don’t have V2G capability, but it’s coming

There’s also the issue of a lack of functionality on the car side.

Most current generation EVs don’t have the capacity to perform V2G or V2H charging. The only two cars currently on sale that can do it are the Nissan Leaf and Mitsubishi Outlander, the latter with a smaller battery because it’s a plug-in hybrid with a petrol engine.

Each has a CHAdeMO DC charging plug, commonly used in Japan.

CHAdeMO already has the capability to reverse the flow of electricity.

The DC fast charging plug mostly used in Australia is called CCS combo (it incorporates a Type 2 plug for AC home charging) and does not yet have the capability to perform V2G.

But CCS chargers are one step closer to V2G capability, following the release in March of an ISO standard. That’s a crucial piece of the puzzle that Washington says will kickstart the commercialisation and widescale uptake.

“Car makers, charging station manufacturers, etc, will now go full steam ahead to develop products,” he says, adding that he expects start-up brands such as American company Lucid to lead the way.

In launching its Lucid Air in the US, the company started by a former Tesla chief engineer said it was enabling “full bi-directionality for advanced vehicle-to-everything (V2X) capabilities”.

And Volkswagen, which is fast expanding its EV footprint, is an early adopter. In revealing its ID.Buzz – effectively a modern day EV Kombi – the company said when global deliveries start in September, the futuristic wagon would have vehicle-to-home functionality.

Washington says he expects “full commercialisation by 2025”, potentially increasing the appeal of EVs.

Vehicle-to-grid charging in WA

V2G is on the radar for the Western Australian government, but it says the priority is “preparing the electricity system for EV integration” and that “implementation is still some way off”.

“V2G is not essential to EVs helping the power system – just as important is helping the power system manage intermittent generation from renewable sources,” said a WA government spokesperson, adding that “when and how fast an EV is charged matters to the grid”.

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The government says the ability for EVs to supply electricity will likely initially be focused on home integration above feeding the grid.

“EVs with a basic level of charge will be the priority for many households, rather than providing services to the power system.”

But V2G is planned as a trial under the Government’s Electric Vehicle Action Plan.

“This is not due to occur until later in 2023, with the initial focus on more immediate challenges of preparing the electricity system for EV integration.”

Plenty of range to drive, and to power your home

There’s little doubt the potential is there for EVs to play a significant role.

Estimates released by the Australian Bureau of Statistics late last year showed an average electric passenger vehicle travels 11,100km annually, or a little more than 30km per day.

Most EVs now have a range between charges of at least 300km, many between 400 and 500km.

In other words, in excess of 90 per cent of the battery range is not being used to power the car each day.

The top-selling EV in the country, the Tesla Model 3, has a battery capacity of at least 55kWh, versus an average household’s average daily electricity use of 18kWh. Many have bigger batteries.

So there would be no shortage of electricity in powering a house overnight – or longer, provided the car has the functionality.

And the WA government acknowledges “in the longer term, V2G technology may mean that EVs can help meet peak demand, too”.

If households rush to the technology – something highly unlikely given its current cost and limited usability – and install wallboxes or regular EV chargers that aren’t connected, or smart, there could be challenges with overloading.

“If we have charging that doesn’t have these smart capabilities then there are concerns that if everyone comes home and charges at the same time … that could be quite bad,” says Jafari.

The WA Government is aware of the challenges and has its eye on connected systems.

“In the United Kingdom, newly installed home chargers must be ‘smart chargers’ and default to not charging during the peak periods,” said a spokesperson.

Given the timing and the push for gadgets and even household appliances to be connected, V2G and V2H tech is already planned to be smart, with the Quasar unit connected to the cloud, constantly communicating to ensure it’s maximising electric supply and recharging opportunities.

It’s a tantalising taste of new technology that could have broad appeal, once more options become available.