Welcome to Engineering with Rosie. Today's video is about vehicle-to-grid technology, V2G, which is something that I'm
really excited about because it has the potential to help solve some of the most challenging aspects of the clean
energy transition. But even though the technology holds a lot of potential, it isn't being used on a large scale yet.
In this video, I'm going to ask a V2G expert a bunch of questions I have about the technology and if why it's so
great, why isn't anyone using it? I recently had the chance to talk to Bjorn Sturmberg, who is a researcher at the
Australian National University working on a V2G project called REVS: Realizing Electric Vehicle to Grid Services.
Now, that project will have 51 electric cars which are part of the Australian Capital Territory government's fleet, and
they'll be demonstrating on this relatively large scale how V2G can work. I helped Bjorn and his team make an explainer
video on their technology which you can find here for a good explanation about the REVS project and V2G in general.
So the way it works is that batteries in electric vehicles connect to the electricity grid via a 2-way charger. They
monitor the grid frequency to tell whether there is a balance between electricity supply and demand. So when
demand is higher than supply, the frequency drops and the REVS batteries will kick in to supply power to the grid. And
when supply is higher than demand, then the frequency will rise and the REVS batteries will start charging to take on
some of that extra load. Now I have been a long-time fan of V2G, because it kind of feels like buy one get one free. We
buy electric cars to clean up transport system. And we get the freebie of extra electricity storage to help solve some
of the big challenges related to an electricity grid supplied by a lot of variable renewables.
So in the past, when we had really physically big generators with heavy rotating turbines generating electricity, the
system was pretty tolerant of small changes in demand, these massive turbines have a lot of inertia, they're really hard
to slow down quickly. So that makes it relatively easy to keep the system balanced. Without that physical inertia, the
balance can be disturbed more easily. So we will need a fast responding option that can keep the system balance. And
since batteries don't have any huge heavy components that take a long time to start up, they can provide that really
fast response. And when you think about car batteries, all of them together, it's actually quite a lot of storage
that's available. Even though people buy cars to drive around, they actually spend most of their time parked, that
valuable asset just sits there most of the day doing nothing.
You can supply a house's electricity for several days off a fully charged electric car battery. And if all of
Australia's vehicles were electric, the total storage is huge. It's about five times as large as the Snowy Hydro 2.0
pumped hydro project that's currently being built in Kosciuszco National Park. And it's more than 10,000 times
larger than our famous Hornsdale Tesla big battery. In fact, it's over three days of the current electricity consumption
of the national energy market, which covers all of the eastern part of Australia.
So like I said, I am a huge fan of V2G and I have been for years. The idea isn't new. There have been plenty of trials
before this ANU one that have already demonstrated the capability of vehicle batteries and the two way chargers to
provide this service. In fact, the ANU REVS project uses off-the-shelf commercially available cars and two way
chargers, so no new tech there. But if the benefits are so big and the technology is already available to buy, then why
haven't we seen V2G rolled out all around the world, wherever there are a lot of electric cars or anywhere that
needs more electricity storage and then next. So this question had been bothering me for a while but recently I
got a chance to find out. I visited the ANU to see their first car and 2-way charger in the REVS project. And I
caught up with Bjorn in the distributed energy resources lab to ask him a whole bunch of questions about V2G and what the
remaining challenges are to see it go from small scale trials to mainstream rollout.
My first question was one that I have heard many people express concerns about: won't the car batteries get damaged
from so much charging and discharging? I mean, people are already pretty worried about battery life for EVs that are
just used for regular driving. If we use it for V2G too, is that going to shorten the life even more?
Yeah, two parts, two-part answer. The first is that what really impacts battery life is when you drive with them in
high power. So going back to that how much energy you put through a battery over a year has less of an impact than the
way in which you do that. So if you charge really hard, discharge really hard, that has more wear and tear than if
you charge slowly over day and then discharge slowly over the nights. Now, electric vehicles are an example where
you're driving a battery really hard because you want to accelerate, that's really a much higher wear and tear use
case, than vehicle-to-grid, where you're generally, like using power more more gently or softly. The second part of
it is that with the way that we're using our vehicles for the vehicle-to-grid, they're really getting paid to just be
available to be on call for the power system. So whenever they're plugged in, they're monitoring the frequency, and
they're ready to charge or discharge power if needed. We only have situations where the grid needs that extra power a
dozen, two dozen times a year, it's really only when there's a major disturbance to think of like a big storm or
something coming through knocking out a power station. It's only in those rare occasions that you actually need that
power. So the actual wear and tear on the battery is very little because you're only using it very sparsely.
Okay, so that's the first objection out of the way. Battery degradation shouldn't be a problem, because you can get a
lot of benefits from V2G without actually running the batteries very hard or cycling them very often. But what
about the huge extra load on our grid? Like I said before, if you add all the batteries up together, they make a huge
amount of power. If we're charging all those cars at once will we need to upgrade our grid before we can start adding
a lot of electric vehicles?
So a couple of parts to that. So yes, electric vehicles, obviously need electricity to charge. And if all of
Australia's vehicles, including trucks and buses were electrified, that might be about a third more electricity
than we use in total at the moment. But that electricity, they need that in in quite a flexible way across the year.
So you can spread out that another third of electricity that we need to produce, we can spread that out. and beyond that,
we can also then match when we're charging our vehicles with when there's abundant wind and solar generation. So it
really is a way in which you can get flexibility in shapeing that load in charging those vehicles can really assist you
in making the most of your solar and wind resources. And then there's the whole additional, like positive of being
able to draw upon the energy that's in the batteries. So that's the vehicle-to-grid part of it, where if all of the
19 million vehicles in Australia were electrified they would store five times as much energy as the planned Snowy 2.0.
There are two components to it, it's like the power component and the energy component. So that comparison,
actually with Snowy 2.0 is comparing energy. Yes. Like how much power over time you can store? Yeah, how much water is
in the dam? How much water is in the dam, how many electrons are one side of the battery. And that really is not, that's
the kind of energy storage is the forte of pumped hydro. Yeah, that's kind of it's one trick that it is really good.
You can store a lot a lot of duration of energy without adding a lot of cost.
Yeah. Whereas batteries generally don't get used so much for energy storage. You're really more after the power
component, which is that they can go from maximum discharge to maximum charging in under a second. so you have a lot of
power that you can draw. So that comparison with Snowy 2.0 actually looks even better if you compare power of batteries
to the power of Snowy Hydro.
So you're talking about the rating, like how big the generator is? The electrons are coming out per second or
whatever. Yeah.
Alright, so there's two aspects to it, yes, there will be huge extra demand. But if we use smart chargers, then we can
actually use that demand flexibly to soak up extra renewables when there's a lot in the system. And then you've
got the storage component. But how does that work exactly? How will my car battery be used to support the system but
also still function as a car, I mean, that's what I bought it for, right?
When there's an unexpected event, such as a storm takes out a powerline, takes out a power station, or takes out a
really large load as well.
Like a smelter, an aluminium smelter?
Yeah, suddenly goes offline, and you have a lot more power than you need, your frequency is going to deviate, either
going up or down. And then what how our market is set up is that once the frequency goes out of a certain bounds, then
there are a number of generators that need to kick in and are responding within six seconds, 60 seconds, or five
minutes. In each case, it's the same idea. But as a generator, you've committed to jumping in when you're called
upon. If there is then an event, you then need to provide your power within that time. As we kind of clean the
electricity system and get more renewables. Therefore, you kind of have more variability in generation and want to
match, to control that by having more storage in the system, we're moving towards having a faster frequency response
market as well might be responding in less than a second. That's really really well suited to batteries.
so that's interesting. I can see how in the future when we've got our ... our V2G all set up nicely and I've got my
electric car plugged in at home and I can easily respond in six seconds. But then how long is it going to go for? Are
you gonna... Am I going to get in my car and I want to go I want to drive down the coast and I find my battery's flat
because it was preventing a blackout or you know, like, I'm not gonna, I'm not gonna be happy with that.
So really just using the energy in the vehicle's battery for these really critical moments that occur very rarely across
the years and one at most two dozen times a year. And during that event itself, it's really about the role of batteries
in particular, is about providing power really quickly. So within six seconds, our EVs will be discharging at full
bore, but will only generally have to hold that power for sixty seconds. so a minute's worth of power out of your
electric vehicle is gonna have no impact on how far you can drive.
Okay, so if battery degradation isn't a problem, and the large added demand from having a lot of EVs can actually be
a good thing, because it adds demand flexibility. I also won't have to worry about my battery being drained when I
want to use it. And we have a lot more agile system when we use batteries instead of the old inertia based system. So
that's a lot of pros so far and no cons yet. Which doesn't make any sense to me because V2G is not being used anywhere,
not on any large kind of scale yet anyway. So why don't we just roll this out as fast as we can get a these into the
country?
To be honest, it seems to me like we're stuck in this old fashioned way of thinking, just, you know, like not really
recognizing the possibilities, only thinking about the problems, we try and make electric cars as much like petrol
cars as possible, try and squeeze all the new energy technologies into the old systems constraints, you know,
where we had to deal with baseload and we had the inertia as both a pro and a con. So it seems obvious to me that if we
would just instead embrace the possibilities of this new agile, flexible energy system, that would pretty much just
work out better in every single way.
You're providing an essential service that's relied upon every day of the year, second of the day, it's very hard to
change that in process. you don't have the luxury of kind of being Alright, everyone, no electricity for a year, we're
gonna reboot everything and then start from scratch. which would make the transition almost infinitely easier.
That's how I would do it as an engineer like that sounds very neat.
Just turn everything off for a good second and start from scratch. Yeah, it would be much, much easier.
Good plan! Everyone would be happy with that.
Everyone will just be like "candles and camping for the next year," and then we'll get back to it. So no, I think that
moving it while it's in process, that's the real challenge. And I agree that in the electricity system very much the way
that we're talking about particularly inertia, which we talked about in the context of these frequency support that
our vehicles are doing. That's something that we are kind of familiar with, because that's the way that generators and
fossil fired, power stations happened to work, they happened to have a mass that spins. But electronics works entirely
differently, it has a lot of advantages, and how quickly it can work and how how it works is at the discretion of the
humans who program it. So we could be developing in an entirely different way, if it was up from scratch. But
instead, we're in a situation where we're trying to integrate new technology with old technology. And we've got
to do that in this seamless way that we can go from lots of one to all the other without the lights ever going out.
Electric vehicles have really been trying to prove themselves as vehicles, as vehicles kind of quite closely
match to conventional vehicles as possible. They're really trying to like prove out range and kind of looks the same as
a regular vehicle and does all the same things. But as a vehicle manufacturer, it's quite daunting, I think, to start
having conversations with your customers not around how fast can you accelerate, how cool is this car, how smooth does it
drive, how quiet and all those sorts of things. But to be like "oh, so how do you get your electricity?". Like that's
not a conversation the car manufacturers have ever had before. And the flipside is also true that for electricity
companies, they're very used to selling electrons, they're not used to selling cars, or talking about how to charge
your car. So there's new conversations that both the electricity sector need to have with customers and the
transport sector that needs to have with customers and that the transport and electricity sector need to have with each
other and finding the comfort that you have addressed the previous kind of attacks on electric vehicles that they go
that they ruin the weekend or whatever some politicians have claimed. So it's kind of one of those, we can now go out and
actually be like, not only do they do all the things that you want from your car, but actually, they'll avoid you ever
having to go to a petrol station, they'll be able to power you when you go camping. They'll be able to power your house
for a couple of days in a blackout.
Yes. Okay, point taken. So I was pretty much just being a typical engineer focused way too much on just the
technology. I didn't see any technology issues. And so I was like, why are people being so dumb? Why isn't V2G already
everywhere? And the reason is that it's not actually the technology that's not ready it's not the car batteries. It's
not the two-way chargers that we're gonna have a problem with. It's how do we use it and how do we absorb it not just
into the electricity system, but also into business models?
And that's one of the things that REVS is really delivering on because we're not just having these vehicles kind of
testing them in the lab or out in the field to see if they do respond to frequency. They're really out there. And
whenever they're plugged into the grid, they're getting paid to be on-call. So we're doing all of the integration between
the vehicle and the charger, the fleet company who manage the fleet of vehicles that we're working with, the
electricity retailer who's then bidding that availability of battery capacity into the national market, getting paid for
it and then the money comes back down through the chain of organizations There's all of that that needs to be put in
place. And as I mentioned earlier, kind of the transport sector and the electricity sector have historically been
pretty separate. So there's a lot of kind of new conve sations and new systems that need to be put in place acros
those. We've got to go through this process, for first time and the first time you do something's always the hardest. T
e idea of these trials to do it once have a lot of learning nd then have it be easier for others to do the same thing
nd bring V2G kind of to the mainstream. The acronym REVS i mostly because it sounds like revving your car, but it's al
o about realizing this service.
Awesome. Thanks Bjorn. I was actually so satisfied by that i terview, I really did get my answers for my main question.
f V2G is so great, then why aren't we using it? And I will still remain a V2G supporter because the potential that I
aw is there. It can make the challenge of transitioning to a clean economy easier on several fronts.
I want to mention that Bjorn told me he's been working on a kids' book about the energy transition, which I thought
sounded really cool. And if you're interested, there will be a Kickstarter campaign on that coming up. So I'll put a link
in the description to where you can get in on that if you want. As always tell me in the comments. If you found
anything in this video confusing or if you thought I missed some obvious questions, or if you'd like to suggest a topic
for a future video. And if you want to support the channel and help steer its development, then you can join the
engineering with Rosie Patreon community where we come up with ideas for questions for upcoming interviews, we vote on
topic ideas for future videos and share advice on how to improve production quality and stuff like that. If you're
interested in clean energy technologies and the engineering behind them, then check out the other videos on my channel
and I'll see you in the next one.
Doesn't it look funny with that. Yeah, but that's like part of the charm.