After a big spike in sales of fully electric and hybrid cars as drivers rushed to take advantage of the Clean Car Discount before the incoming coalition government removed it, the numbers went into reverse at the beginning of the year, Motor Industry Association figures suggest.
The government further disincentivising EVs and plug-in hybrid use by not extending their exemption from road user charges, along with inflation and high interest rates eating into people’s disposable incomes, no doubt contribute to sales numbers flagging as well.
This is arguably not the most conducive environment for launching a marketing drive for home chargers like WEL Networks subsidiary We.Ev has done.
Dirty fossil fuels need to be phased out, they’re not getting cheaper, and electricity to power vehicles is a cleaner and more compelling proposition. What’s more, there are now nearly 106,000 BEVs (battery electric vehicles) and PHEVs (plug-in hybrid electric vehicles) in the nation’s passenger car fleet.
They have to be charged. Being able to do it at home instead of using a public charging station is attractive for many EV owners. It’s convenient, and usually cheaper, particularly if you can schedule the charging to be done out of peak usage times with lower rates.
However, charging at 230-240 Volt and 10 Ampere is slow. From personal experience, using a thick extension cord, you charge at somewhere between 1.8 to 2 kW.
Depending on the capacity of your EV’s battery, and how depleted it is, you’re looking at a long charging session at that rate. PHEVs have smaller batteries and a Mitsubishi Outlander with 20 kWh capacity can be topped up overnight from a standard power outlet.
It’s worth remembering though that even 2 kW through what’s officially called Mode 2 charging is a good chunk of power. Caution is warranted, particularly if you’re running long charging sessions sometimes for more than a day at a time.
“I’m pulling my hair out when I visit places like Waiheke island,” We.Ev product manager Sam Montgomerie said.
“It’s terrible to see all the Nissan LEAF drivers running extension cords out of their windows, across the garden,” Montgomerie said.
Montgomerie said charging EVs this way is a messy trip hazard, and doing it in the rain is not particularly safe either. A constant high electric load also generates heat that standard three-pin sockets aren’t designed to handle for extended periods, and this could be a fire hazard.
To tidy things up, cable-wise, and speed up charging, you can buy more powerful Mode 3 chargers that use single-phase AC electricity at the same 230-240 V but a much higher current, 32 A.
They give you a much higher 7.4 kW charging rate, but that comes with its own set of issues, Montgomerie points out, particularly with grey imports that may not conform to New Zealand standards.
Electricity companies are keen for these chargers to be smart with control over the output, similar to the ripple relay control for hot water cylinders.
The reason for that is to avoid bringing the mains grid to its knees with demand surges. To quote the Energy Efficiency and Conservation Agency sponsored Standards NZ 6011:2023 document:
“If every New Zealander owned an EV, and we all plugged them in at the same time (such as when we got home from work), we would need to invest much more in the electricity network to meet this additional demand.”
“That would result in higher electricity costs for everyone. Smart EV charging allows you to increase or decrease your charging level, often to take advantage of lower-cost off-peak electricity.".
Not every New Zealander owns an EV, and it’s unlikely to ever be the case, but you get the drift. Montgomerie explained that a correctly installed smart charger would do hard on/off switching.
“It’s just a throttle-back, so rather than your charger pulling 7.4 kW, we’ll pull it back to 3 kW for 10-15 minutes,” he said.
If the home charging isn’t managed correctly, WEL would be looking at spending $1 billion over the next 15 years to bump up grid capacity, which would be more than a 100% increase in its current network value.
Electricity demand is likely to go up substantially in the near future, as people replace gas. Induction hobs, underfloor and water heating all have big electric power draws. Adding high power AC home charging for EVs would exacerbate the demand for electricity.
If 7.4 kW is good, then 22kW is three times better, right?
Compared to fast direct current (DC) charging that can deliver 180 and 300 kW, 7.2 kW for AC home charging may seem a bit anaemic.
Ratcheting up the charging power to 22 kW with a beefier unit may seem tempting, but there are plenty of caveats to bear in mind.
First, you’ll need three phase power. If you don’t have it already, like for example many rural properties do, it’s not cheap.
The cost of upgrading your house to three phase power can be as high as $10,000, Montgomerie explained, with the cost of the charger itself on top, of course.
EVs that charge faster than 11 kW are still not common either.
Even with 7.4 kW kW home charging, if it’s possible to install three phase power safely via a main distribution board, and the budget for doing so is reasonable, it can make sense if there are multiple EVs to charge.
Making EV charging even smarter
While there are challenges to overcome when it comes to electrifying our transportation, and charging vehicles of all kinds at home, Montgomerie pointed out that batteries are going to be a thing of the future.
“What we’re failing to understand is that by bringing an EV home, we’re actually bringing a massive battery to the house as well,” he said.
This refers to a feature that Nissan in particular has been keen to advertise, vehicle to load or V2L. You can use your car to charge other devices, and even use it to power your house.
One such scenario is to use solar to charge the battery in your car during the day. Then you change the direction, and power your house, in the evening. A vehicle battery powered property would be more resilient to electricity outages as well, and help smooth out demand peaks.
The car needs to support V2L, and several brands like Kia offer it, with Tesla also implementing its variant of the feature, called Powershare. EV chargers would also need to support V2L.
“There is no reason why in the future your car won’t have a vehicle to grid capability so that you’ll actually be able to power your home, or the grid, in that manner, off your EV for a couple of hours.
The V2L or V2G feature would be very desirable to many people, and adds functionality to EVs that fossil-fuel vehicles simply cannot provide. If there's a reason needed to bring back the Clean Car Discount, V2L/V2G is high on the list.
Update April 12, 2024: The Minister for Energy, Simeon Brown, says there are law changes coming for EV charging.
"One of the changes I am considering as Minister for Energy is an alteration to the Energy Efficiency and Conservation Act to better provide for EV smart charging," Brown said.
"There will be increasing pressure on both the national grid and EDBs as New Zealanders choose to purchase electric vehicles. Non-Smart Chargers begin to charge vehicles as soon as they are plugged in. This can lead to large spikes in demand as people return home from work," he added.
"Smart Chargers are one important way that we can ensure there is a smoothening of demand without compromising service for the EV owner.
Officials are currently working on advice for me that will confirm the scope and timeframes of this work," Brown said.
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