EV charging: options, ‘personas’, data and a breakthrough for electrification

Feature image for EV charging
Electric vehicle (EV) sales trebled in Australia last year. This exciting, accelerating rise of EVs brings together three of the biggest infrastructure investments affecting our everyday lives: our homes, our personal transport, and our household energy assets like rooftop solar. With the right data, we now have unprecedented opportunities to contribute to a Net Zero future through how we live day to day.


I know not everyone is as excited about EV charging as I am. 

And yes, I deliberately mean the charging, not the vehicles themselves—although I very much enjoy driving my wife’s Nissan Leaf e+ on the rare occasions she’ll surrender the wheel! 

Cars aren’t really even my thing, though I am looking forward to the phasing out of internal combustion engine (ICE) vehicles. 

Meanwhile, what I am becoming is a solar-charging fanatic.

I love being responsible for charging an EV, because it’s a beautiful load to soak up our rooftop solar. The vast majority of electrons going into the car at our place are free from the sun, and it’s my job to manage this.

Currently, Covid 19 is helping me. Home EV charging in the time of the global pandemic, with both of us working from home, means the car is mainly parked at home during daylight hours, and so are we.

This is where energy data is especially valuable. Armed with my Wattwatchers device and the MyEnergy app, I know immediately when to charge and when not to, also taking cues from the weather and the time of day.

I can tweak and fiddle too. 

If there’s not a lot of sun, I’ll turn off the pool pump if it’s competing with the car for solar electrons. I time the dishwasher and other lesser loads like clothes washing accordingly. 

As a stretch-break opportunity to escape the computer, I’m more than happy to be popping in and out through the day, manually turning different loads on and off to maximise solar self-consumption and clean energy for home and vehicle.

For many, however, this bit will need to be automated and remotely controllable.

Image to illustrate EV charging blog post
To optimise home charging from solar you need to align two key things: the sun needs to be shining and the car needs to be available. On these three consecutive days in January 2022, Day 1 (left) went reasonably well – apart from an afternoon power outage (you can see the white line after 14.40) – but the car wasn’t fully charged, and then was used in the evening. So Day 2 still required more charging at night to prepare 100% for a long road trip. Day 3 had lots of sun, but no car to charge. The smaller load starting in the morning about 8am and running until after 6pm is a pool pump on a timer, which gets adjusted as the seasons change. SOURCE: Wattwatchers MyEnergy app (dark blue is grid-supplied electricity; light orange is solar generation; dark orange is solar used on-site).

There’s going to be a lot of charging

On average Australians own 1.8 vehicles per household, for a total of over 17 million vehicles, with Australia having nearly 10 million households.

So one way or another, there’s going to be a lot of charging going on as EVs proliferate, each using on average about 10kWh a day (roughly about half an average Australian home’s daily consumption of 18–19kWh).

From what I’ve been observing, we’ll need multiple charging point options for every EV on the road, and over 90 percent of all charging will happen in or immediately adjacent to buildings—which means a lot of energy management.

Research indicates that most of this will be in our homes, followed by work, then destinations like supermarkets, and places that look like today’s service stations might actually end up at the end of the queue.

For this discussion, let’s put aside highway fast charging-type installations to service long distance travelling (Level 3 charging). These are big investments and only the very wealthiest of people will have anything like them for personal use at home.

I’ve been composing a rough hierarchy of home charging options, not all of which are available commercially yet (in Australia at least):

  1. Standard 240V power outlet using the charging cable supplied with the car, and possibly an extension lead. It’s the slowest charging option, and from what I’ve experienced can take 20 hours-plus to go from an empty battery to a full one. An adapter may be required if you have a 15 amp power outlet rather than a standard 10 amp one. (Technically known as ‘Level 1’ charging, or colloquially as ‘Granny charging’ in the UK.)
  2. A dedicated charging wall-box installed by an electrician, which speeds up the charging, but isn’t ‘smart’ in terms of over-the-internet communications nor remote control. It’s faster than a standard power outlet, but nowhere near as fast as a fast-charger. Cost appears to be in the range of $800—$1500. (This is a type of ‘Level 2’ charging, and also is commonly being called ‘dumb charging’.)
  3. A single-direction ‘smart charger’, which costs more because it includes over-the-internet communications and remote control (i.e. ‘you can have an app for this’). It’s faster than a standard power outlet, but nowhere near as fast as a fast-charger. Cost appears to be in the range of $1500-plus. (This is the other type of ‘Level 2’ charging, and is commonly being called ‘smart charging’.)
  4. Then we’ll be moving up to bi-directional smart charging, although the technology for this is still not commercially available as yet, at least in Australia. While options 1–3 above are only for charging the car, with a bi-directional charger the car will be able to discharge back into the house or building (note that most EVs currently in the market are not equipped for this). If the energy isn’t consumed in the premises, it then goes into the grid. This effect is likely to become a very big deal beyond 2025 (or sooner, if EV uptake accelerates beyond current predictions). I’ve heard cost estimates in the range of $10,000, at least early on, so it’s not exactly ready to go for mass rollouts! This will come in two main modes, being:
    1. Vehicle-to-Home (V2H)
    2. Vehicle-to-Grid (V2G)
    3. And it could be both of them (V2H/G)

Who will be doing the charging and when?

Many factors will affect the question of what charging strategy will be best for you? And what will be best for the electricity grid? (Which may be two different things entirely.)

These factors include: Where you live, whether or not you have rooftop solar, where and when you work, and how interested you are in related themes such as grid stability and reliability, technology innovation, the environment and climate action, and saving or even making money.

I’ve looked at early work on developing ‘personas’ or ‘avatars’ for EV owners and potential owners. The best source I’ve seen thus far has focused on potential buyers and their motivations—more from the straightforward point of view of buying a car, rather than buying a mobility solution that integrates with your household and home energy assets, much less the electricity grid.

Escalent’s EVForward study is billed as the world’s most comprehensive study of future EV buyers (beyond the first round of ‘early adopters’), and it has generated six personas, with three unlikely to buy EVs (Old Guard, Skeptic and Survivor), and three likely (Steward, Young Enthusiast and Torchbearer). Each of these personas have a propensity to buy for quite different reasons, and with significantly different expectations.

I’ve been thinking about personas in a different way, based much more on EV charging strategies rather than vehicle purchasing considerations.

Here’s what I’ve come up with thus far:

Home ‘Solaristas‘ – like me, they’ll want to maximise charging free from the sun using their own rooftop solar systems. Their motivations are likely to be a mix of saving money and optimising their solar investments, environmental concern and climate action, and a measure of being independent from the grid (i.e. ‘the system’). Unless they are working from home, at least most of the time, they are likely to be frustrated because of the mismatch between their charging ‘ideal’ and their day-to-day reality. Many will be able to make do with Level 1 charging with a standard power outlet, but might invest in Level 2 charging if it allowed them to make better use of their solar by charging faster. Some will even consider a smart-and-clean home energy trifecta of solar panels, battery and EV, although the financial and environmental value of this needs close analysis (for a start, car batteries typically have 6–10 times the capacity of a home battery).

All-Day Parkers – these are people who drive to their work location during their working week, park their car for the whole day, and then drive home at the end of the day. Think school teachers, nurses and doctors, factory and warehouse workers, and many office-based workers too. Arguably there’s a convergence of interest between them and the electricity grid to ensure they can charge from the grid during the day, when abundant low-cost solar will be available (at least on sunny days). Their car batteries will act as a solar sponge, and ideally in the future they’ll have bidirectional chargers at home that will allow them to discharge into their homes and the grid during the evening peak. Potentially, grid operators could subsidise the charging infrastructure required at both the workplace (or adjacent car parking) and at the home; and the electricity they use for charging during the day could be made ultra-cheap, if not free.

My-Car Purists – for this persona, it’s all about the vehicle. And this may be a lot of car owners. They couldn’t care less about helping grid stability, or saving or earning a bit extra via their electricity bills. But they may well still invest in Level 2 smart chargers because they want to make sure their vehicle is charged and ready to go, in the shortest possible time, without worrying too much about the cost or sustainability of the ‘fuel’. They may be susceptible to gadgets or apps that make their car ‘smarter’, or ‘sexier’, and possibly to service providers who manage the charging infrastructure, but they’ll still put the car above everything else.

On-The-Roaders – whether it’s their own car, or a work fleet vehicle, sales, service and delivery people who are on the road most of their working day will be highly-focused on maximum travel distance per charge, coupled with minimum time for charging. They will be more likely to use Level 3 fast chargers when they are out and about, and they’ll want the vehicle fully-charged when they leave home in the morning (unlike all-day parkers, who may only need enough charge to get back to their workplace the next day). So they are likely to value Level 2 charging as well, whether dumb or smart, if charging from a standard powerpoint overnight is too slow.

Common ‘Properteers’ – body corporates and apartment-dwellers will need to match EV charging needs, often with parking in their basements, to strata levies (because the electricity for common property areas is a shared cost for residents). They may end up with a mix of Level 1 and Level 2 charging, with payment reconciliation requirements pushing them towards smarter, more expensive charging solutions. (Sydney-based Wattblock, which has partnered with Wattwatchers on energy monitoring in strata buildings, has created a video discussing The Case for EV Charging in Strata.)

Recharging is different to refuelling

In short, an EV world is looking significantly less homogenous than an ICE one when it comes to recharging versus refuelling. 

Charging strategies will need considerably more attention by car owners than stopping at a convenient service station. Depending on your vehicle use case and living/working arrangements, you may need quite different infrastructure.

Things get even more complicated for households with multiple vehicles and different personas under the one roof. Charging two EVs at home, on rough calculations, could easily double a household’s total electricity consumption. And a lot of this assumes you even have suitable off-street parking.

For now, most of those who own cars are still in ICE mode, but if the world is going to meet the goal of Net Zero for greenhouse gas pollution by 2050 at the latest, then Bloomberg New Energy Finance says we need about 60 percent of all vehicle sales to be EVs by 2030.

Before buying your first EV, you can start preparing by installing smart energy monitoring devices (like Wattwatchers) to better understand how your home (or strata building) uses electricity, what your solar is doing (if you have it already) or plan to get PV installed, and what kind of charging infrastructure you’ll need.

For business and public sites, detailed energy monitoring data also will help you to plan for and implement EV charging strategies, including how you manage charging within the demand charges and peak capacity limits for your site.

Murray Hogarth is Director of Communications and Community Networks for Sydney-based Wattwatchers Digital Energy.