Electric Vehicle to Grid Technology Explained

If Vehicle-to-Grid technology is so amazing, then why isn't anyone using it yet?
Today we visit Bjorn Sturmberg, a vehicle-to-grid researcher at the Australian National University to ask all my questions about V2G and why it's not a thing yet.

Kickstarter link for Bjorn's book Amy's Balancing Act

Bookmarks:
00:00 Intro
01:03 How does V2G work?
01:52 Intertia in the electricity system
02:24 Cumulative storage of millions of EVs is huge
04:13 Q1 - Will V2G shorten battery life?
05:50 Q2 - Will we need to upgrade our grid?
08:08 Q3 - Will V2G leave my battery empty?
10:36 Q4 - Why aren't we taking advantage of V2G now?
14:29 Q5 - What will V2G business models look like?
16:10 Summary and Bjorn's energy transition kids' book h
17:30 Bonus blooper

Extra reading:
On battery degradation from V2G

What can 6,000 electric vehicles tell us about EV battery health?

A-Z of V2G - a summary of basically every V2G trial around the world

V2G Around the World

Sources:
Coal and nuclear power plants animations:Tennessee Valley Authority, Public domain, via Wikimedia Commons
WattClarity images (supply and demand charts of Australian National Electricity Market):

#technology #engineering #stem

Thanks for watching the video "Electric Vehicle to Grid"

[EngineeringwithRosie]

And the Kickstarter link for Bjorn's book Amy's Balancing Act:

[latemnetlom]

Fun and informative as usual Rosie! A few quick points:

1) Your guest is partially correct that power (C rate relative to the battery's C rating) during charge and discharge is somewhat related to battery degradation. But so too is time spent at high voltage, i.e. high state of charge (SOC). If a V2G scheme holds your car at a higher SOC than you would ordinarily do, it's degrading your pack prematurely relative to just staying away from high SOC, which smart EV owners are already doing. They charge to full just before they leave on a long trip, and stay away from high SOC the rest of the time.

2) All battery cycling causes degradation too. You can waffle and say that it doesn't cause enough degradation to worry about, and you might be right- but that depends on points like 1) above plus on how often you do it and the C rate you do it at, and what fraction of full pack charge you use each time.

3) Installing 50-150 kW fast chargers just to do V2G ain't gonna happen- it would be too costly. So you're talking about perhaps Level 2 (3-7 kW) connections. At those power levels, and assuming that the events you're trying to protect against on the grid really are only 15 minutes in maximum duration, you're really not talking about the batteries having much energy capacity. 19 million cars x 6 kW is an absolute sh*tload of power, either as demand response (charging which starts or stops when the grid system operator wants it to) or as a virtual power plant- 114 GW! But if it only goes on for 1/4 hour worst case, it's a much more modest 28.5 GWh of energy available. Also a small fraction of a typical car's battery capacity being used- 1.5 kWh per car, or perhaps 5% of the charge in a 60 kWh pack in a worst case event. Doing 5% cycling on a battery pack a dozen or two times per year is really not something I'd be worried about as a car owner- I wouldn't be too worried about how much that was damaging my pack. I also wouldn't be too worried about who made the revenue from what could be a small number of very high value kWh. Do that DAILY however and I would be concerned! I'd want money for that, for sure.

In summary, I agree that V2G and even moreso- opportunity charging, i.e. charging automatic start/stop based on the needs of the grid operator- is exciting and interesting. And having the ability to provide emergency response from all those EV batteries? Priceless. I had that possibility in the back of my mind when designing my car conversion project back in 2014- it meant I could run my house's critical systems for days during a prolonged power outage just on my car's battery. Making that "official" by demanding that capability be installed in all new OEM EVs makes a lot of sense to me. It's just the grid connection for cars to supply energy to the broader grid that needs a bit more thought.

[kerilloyd]

Thanks Rosie, great video. I’m on a V2G trial with my Nissan Leaf in the UK. It’s been going for a month now and so far so good. I haven’t had an electricity bill yet so I’m not sure how it’s working with price compared to what i used to pay. To make matters more interesting I also have a PV array which is also feeding into the grid and I’m also on a flexible tariff in the UK called Agile Octopus so it’s difficult to get a grasp of the sum of it all but I’m sure it will all even out in the long run. So long as I’m not massively out of pocket and the trial is a success then I’ll be really proud to have been part of the solution to grid balancing using renewables and EVs.

[pjlecy]

I really appreciate you talking about this subject. You did a great job, keep kicking ass.

[SuperS]

Very good presentation. Bjorn was great. "It's part of the charm" is a great blooper. You'll have to add it to a future blooper compilation. 😂

[AlexPacker]

This one is a source of endless frustration for me too! I have a huge battery sat on my drive doing nothing the whole time I'm at home. It might be worth mentioning that current V2G technology is only supported by the Japanese Chademo connector standard. Most manufacturers have instead adopted the CCS charging standard outside of Japan and China, which unfortunately doesn't support two way power transfer. Therefore most electric cars do not support V2G with the notable exception of the Nissan Leaf and a few others from Japanese manufacturers. Meanwhile I'm drawing fossil fuel power from the grid to run my oven at peak time!

[wyldrushorchard]

Just noticed this video, thanks so much for answering why this isn't the fore most storage option. Like you I have shouted at many electricity storage videos, thinking the answer already exists V2G!! As an automotive engineer, I'm pleased to hear confirmed from people in the field that this is not a technical issue. IE Generators and vehicle OEM's need to find a way of working together.

[richardjackson]

Excellent info.. I had not considered V2G, nor did understand the advantages of V2G quick response times verses inertial power generation. Great job keeping it simple for the rest of us!

[zentouro]

this is such a helpful video rosie! i've bookmarked this link to share whenever anyone asks some of those questions!

[lonnymo]

This sounds really promising Rosie. Thanks for doing this video. Very interesting!

[grbkset-]

Maybe I missed something, but it seems that V2G in this video is meant to soak up excess energy and give it back to the grid in times of need so fossil fuel peaker plants are not needed. I was picturing V2G to help replace non-renewable entirely so that no fossil fuel power plants would be needed. There is a study by RethinkX that says that we can have a fully renewable energy system if we have 3x-5x renewable generation and 1x battery. I think V2G from all EVs can help achieve this (instead of power companies having to purchase batteries themselves). Comment on this Rosie?

[vremster]

Lots of good questions and information. Thank you for sharing all of it!

[dagbruck]

I remember Sydkraft in Sweden looking at V2G in the late 1980’s. I think their focus was more on scheduled use of EV batteries, to compensate for daily variations in energy demand. That coupled with a guarantee to give back a fully charged car at 5pm when you need to go home.

[Soordhin]

I was a pre-order customer for the new fully electric VW ID.3, and was able to take part in a prototype test drive. Which was in its own way interesting, but even more interesting was the huge and very open Q&A session with the development team and their management. V2G came up quite a lot actually, mainly asked and actually demanded by the customers, and VW being very cagey. They stated quite openly though that the main problem is not the technology, that can be sorted out (the CCS standard has not yet V2G but it is in the pipeline), but rather the multi-party business model needed for a read grid based system, and even for a much simpler V2H system (Vehicle to Home) there are questions like for example battery warranty, interaction with the car owners utility company and so on. It seemed they were really interested in that from a technical point of view, but were extremely unsure about any of the many questions around the business side of things.

Of course V2G and V2H are very logical extensions of the BEV ecosystem, especially in conjunction with a photovoltaic system at home.

[protectiongeek]

Another interesting video, thank you Rosie.

The inertia of the power network generators is an important issue often overlooked by many commentators. The increasing penetration of renewables has tended to reduce the network inertia and this could become a concern if the level of penetration threatens to compromise network stability during faults. Power networks tend to operate with relatively high fault levels (corresponding to high inertia) in order to maintain high stability and reasonable power quality. This allows commercial and industrial customers with demanding loads such as large motors to work effectively without causing unacceptable amounts of disturbance to neighbouring customers. High fault levels also means that faults can be detected and disconnected quickly. Reducing system inertia can increase susceptibility to faults and having system inertia that is very low can risk widespread disturbance.

I don't want to misrepresent what you said in the video about the relative inertial characteristics of large, centralised generation and distributed generation as proposed by V2G technology but it's definitely NOT the case that the relatively high inertia of large rotating machines is something to be regarded as undesirable or needing 'engineered out'. Like most solutions, there will be a role for generation sources that underpin system stability (big flywheels, if you like) and distributed sources that can help offset demand locally (small flywheels). The control systems for large rotating machines, coupled with the extremely fast fault clearance times required for the protective devices on transmission networks are very capable of dealing with network disturbances.

In terms of V2G (or other distributed generation) responding to over-frequency (OF) or under-frequency (UF) events, clearly there **is** a role that can be played by these devices but I think there is a danger it could be over-played. The main hazard presented to the system is a severe UF event, usually initiated by the loss of one or more large generators due to failure of the genset itself or the circuit connecting it to the system. Thankfully these events are very rare (well, here in the UK they are very rare - I can't comment on other countries), however among the existing (UK) measures designed to respond to excessively low UF are low frequency demand disconnection (LFDD) devices that are (1) automatic, (2) distributed across the network and (3) essentially instantaneous with no programmed delay. Events triggering the operation of LFDD schemes couldn't be avoided by any amount of V2G implementation as the EV batteries and their charger/inverters would be likely to be disconnected as part of the process.

National electricity network operators invariably have a statutory duty to do all they can to keep the system stable and operate within certain boundaries, hence the regulations that flow from this duty to ensure generators above a certain capacity are subject to central dispatch control. Having lots of potential energy stored in V2G installations is attractive but how could network operator planning and dispatch engineers incorporate any meaningful available capacity from a source that is, by design, capable of being connected and disconnected outside of their control? Over time, researchers and statisticians **may** be able to deduce that a certain percentage of V2G capacity is available at any given time of day, possibly following an availability curve.

The question of whether the grid can accommodate large amounts of either EV charging or V2G installations is - like so many other videos dealing with this subject - dealt with at a 'macro' level, comparing the estimated total stored energy in V2G systems with overall network demand. Yes, smart charging would be necessary and I think EV manufacturers and vendors need to be more open by making it clear that the **availability** of charging at home **may** be restricted at certain times in any given 24-hour period due to the limitations of local low-voltage networks, rather than simply extolling the virtues of being able to export to 'the grid' as if it's as easy and repeatable as plugging in your kettle.

Significant engineering challenges still exist with reconciling the additional loads presented by EV charging to low-voltage distribution networks that were designed and implemented to taper away from the local substation to the load. Although almost all of the very interesting and fertile discussion in this video centres around the monitoring and control of system frequency, the more prevalent issue for individual customers and distribution network operators of voltage control is not mentioned, even though it is of much greater relevance to low-voltage networks than network frequency.

I hope to see advances in V2G technology and much greater adoption of it. I hope to adopt it too, eventually. However, I think there is a lot more R&D required before V2G or domestic renewables in general can be considered as having a significant role in frequency control.

[mikeklein]

Your holistic approach is absolutely essential! Thank you!

[realvanman]

It is a very logical idea. The way to make it work is first and foremost to properly incentivize EV owners, give them control over their level of desired participation, up to and including opting out entirely. Owners need to be able to select their degree of participation at each and every time they connect. If you’re recharging during a long trip, you’ll probably be willing to pay more for a fast, uninterrupted charge. If you’re car will be sitting at work or in the garage, you can simply tell it when you want it to be fully charged, and let it participate in frequency support along the way. The compensation needs to more than make up for the potentially longer charge times and, yes, the decreased battery life. Do not lie about that as otherwise this great idea will get a big black eye in the marketplace. Always be forthcoming. It is an inescapable fact that batteries have cycle lives, and while frequency support service will not significantly consume battery life on the whole, it would be dishonest to state that it has zero effect. I’ll bet that the manufacturers who are warrantying their cars’ batteries would agree.

[returner]

Thanks. This was a handy insight into want V2G can and should be. One of the inhibitors is also that not many of the "first generation" EVs support exporting power, the Nissan LEAF and some other CHAdeMO-equipped cars being the exception. However, that is changing, and soon every new EV will support V2X. And that's my near-term goal; I have two EVs - both with ~40 kWh batteries - and would love to use these in real-time to act as my domestic energy storage solution for excess solar PV...

[AliHSyed]

Fantastic topic and great reporting. Glad I found your channel Rosie. Cant wait for what else you have coming down the pipeline!

[johnpoldo]

This vid was so good, I had to subscribe. As an EE and 4-year EV owner, I find this subject fascinating. Next time, give person interviewed a microphone because many times it was difficult to hear Bjorn. My inexperience with Australian accent made it worse.