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Episode #51: 'EVs As A Grid Asset, Will Utilities Take Advantage' With Charlie Botsford [an Energy Central Power Perspectives™ Podcast]

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The ‘Energy Central Power Perspectives™ Podcast’ features conversations with thought leaders in the utility sector. Each two weeks we’ll connect with an Energy Central Power Industry Network...

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The electrification of transportation is coming whether or not utilities are ready for it. A decade ago, the prospect of vehicles being plugged in every night was enough to keep grid operators up at night at the thought of such an unprecedented load increase, but today the forward-looking utility should instead be looking to the EV revolution as an opportunity and not a threat.

At least that's the position of Charlie Botsford, Program Manager at CWB Solutions and a member of Energy Central's Network of Experts. On today's episode of the podcast, Charlie highlights the baseline situation of EVs on the grid today and how utilities can and should approach everything from increased load, V1G and V2G charging, government EV incentives, and really all the ways that EVs can go from liability to asset. That is, of course, if the utilities plan now to take advantage. And that's what Charlie shares with host Jason Price and producer Matt Chester in this can't-miss episode of the Energy Central Power Perspectives Podcast.

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See also an exclusive bonus clip at the bottom of this post only available to members of Energy Central to hear!

Thanks to the sponsors of this episode of the Energy Central Power Perspectives Podcast: West MonroeEsriAnterix, and ScottMadden

Key Links

Charlie Botsford's Energy Central Profile: https://energycentral.com/member/profile/charles-botsford-pe/about

The latest EV capability - vehicle to load: https://energycentral.com/c/iu/latest-ev-capability-%E2%80%94-vehicle-load

 


TRANSCRIPT

Jason Price: 

Hello, and welcome to Energy Central's Power Perspectives Podcast. This is the show where we bring thought leaders from across the utility industry to share their insight on what's shaping the power sector today and tomorrow. I'm your host, Jason Price of West Monroe, coming to you from New York City. Joining me from Orlando, Florida is Energy Central's community manager and podcast producer, Matt Chester.

Jason Price: 

The intersection of the energy industry with the transportation sector continues to expand. While the industries have long been somewhat connected, the next decade and beyond will see them become even more entangled and symbiotic, with the power sector needing to find ways to safely and reliably provide power to expanding fleets of electric vehicles, and the automakers and transportation planners needing to coordinate with utilities on charging needs and changing power demand.

Jason Price:
Matt, you drive an EV, don't you?

Matt Chester:
Yes, I do.

Jason Price:
What kind of interaction have you experienced as an EV driver with your power provider?

Matt Chester:
I made the decision to buy one, without any specific education from my utility. I was happy to get a very small rebate from them for it, and they helped me pick out the charger that would work best in my garage. But it's all been me coming to them, which I thought was pretty interesting. I would have expected that they would want to incentivize me to do even more.

Jason Price:
Interesting. Well, today's guest, a regular participant in conversations on Energy Central, is looking beyond the interplay of EVs and the grid into what untapped opportunities possibly exist in the coming years that may come from careful planning and shrewd investment. Rather than viewing EVs as a source of power demand, he contends that the batteries of EV fleets are going to be key resources to provide power services to the wider grid, turning that relationship upside down. It's a fascinating topic and one we're eager to dig into. Before we get started with introductions, let's first acknowledge the Energy Central partners who are making today's episode possible.

Jason Price:
To West Monroe. West Monroe works with the nation's largest electric, gas and water utilities in their telecommunications, grid modernization, and digital and workforce transformations. West Monroe brings a multi-disciplinary team that blends utility operations and technology expertise to address modernizing aging infrastructure, providing advisory on transportation electrification, ADMS deployments, data and analytics, and cybersecurity.

Jason Price:
To our sponsors at Esri. Esri is an international supplier of geographic information, GIS software, web GIS and geo database management applications.

Jason Price:
To Guidehouse, formally Navigant Research, a premiere market research and advisory firm covering the global energy transformation.

Jason Price:
To Anterix. Anterix is focused on delivering transformative broadband that enables the modernization of critical infrastructure for the energy, transportation, logistics and other sectors of our economy.

Jason Price:
And, to ScottMadden. ScottMadden is a management consulting firm serving clients across the energy, utility ecosystem. Areas of focus include transmission distribution, the grid edge, generation, energy markets, rates and regulations, corporate sustainability and corporate services. The firm helps clients develop and implement strategies, improve critical operations, reorganize departments in entire companies and implement a myriad of initiatives.

Jason Price:
Joining us on today's episode of Energy Central Power Perspectives Podcast is Charlie Botsford, program manager at CWB Energy Solutions and a member of Energy Central's network of experts. Charlie brings with him 30 years of experience in engineering design, distributed energy, chemical engineering and environmental management. He is passionate about the energy industry and currently, he's got some great focus on the world of EV charging infrastructure. Charlie participates in the California Vehicle Grid Integration working group, the Society of Automotive Engineers of Vehicle to Grid Standard, the West Coast Electric Highway and more, which gives Charlie keen insight into the relationship between electric vehicles and the grid that's likely unmatched by most people in the industry.

Jason Price:
And with those insights, he's been a vocal advocate for the possibility that EVs and the growing fleet of EV batteries in homes, garages and businesses across the country that can be harnessed in a way that benefits utilities, drivers and the grid at large. If you're an Energy Central regular, you've likely run across the numerous posts, comments and nuggets of wisdom that Charlie has shared with the community ever since he joined the platform, way back in 2006. So with that history and his wealth of knowledge, we're excited to hear what he has to say today. So, let's get the conversation started.

Jason Price:
Charlie Botsford, welcome to the Energy Central Power Perspectives Podcast.

Charlie Botsford:
Well, thanks for the intro. You've nailed the setup. Instead of looking at EVs as burden the grid will somehow need to deal with, we should really look at EVs as a way to enhance grid stability, provide grid services that make the future grid resilient and reliable, and enable renewables penetration into the market.

Jason Price:
Terrific. So Charlie, let's dive right in. The situation the energy industry finds itself in is that renewables are important for de-carbonization. Building out grid scale energy storage can help smooth over these issues, but doing so is expensive. So you offer that there is an energy storage solution that can fill that gap more efficiently. Tell us about that.

Charlie Botsford:
Well, yes. More efficiently and more importantly, more cost effectively. We hear a lot about the four hour battery systems that are installed with solar to increase the project value, but then people say, "We need 24 hour, or 100 hour systems, if we really want to replace fossil fuel generation." They do the calculation of how much energy storage that is, how much it costs and it makes their head explode.


Charlie Botsford:
The fallacy in that argument is in extrapolating a local requirement to the bulk grid. In reality, if we install enough energy storage in the bulk, we get to a point of, essentially, infinite hours of energy storage. A great example of this is the operation of the Western Energy Imbalance Market and how that smooths realtime power requirements. Whether we install stationary storage or use EVs as storage, or some combination, we'll eventually get to that same point.

Jason Price:
Well, that's an interesting idea. But, let's make sure we're all working off the same assumptions and definitions.

Jason Price:
How do EV batteries and traditional grid-tied batteries compare? And when we talk about acronyms like V2G versus V1G, what are these differences?

Charlie Botsford:
Yeah. There's a lot of different between V1G, which is also called unidirectional, it's one direction, versus V2G, which is bidirectional. In other words, putting power back onto the grid. Estimates are that when you talk about bulk grid storage, 90% of grid storage services can actually be handled by just simple smart charging, or V1G. Vehicle grid integration, basically. The idea is to control how fast you charge an EV and that's all you need to do, just turn the charger on, turn it off, or some combination there. It's just smart charging and you can do a lot with that. You can even do up and down frequency regulation with just unidirectional charge control. Southern California Edison will be conducting large-scale pilots soon, to demonstrate the capabilities of V1G in the aggregate, meaning in bulk.
 

Charlie Botsford:
But, what's fine for bulk purposes needs a little help for local applications. Which is, for instance, providing power for a house or a building in emergency. For this, you really do need vehicle to grid, or a combination, something called vehicle to house or vehicle to building. It's basically a fancy way of saying you're just putting power from the battery pack back onto the grid or to a house. This has been proven in various forms over the past 20 years, but has really gained a lot of momentum recently.

Charlie Botsford:
I've been fortunate to participate in the Society of Automotive Engineers, SAE, J3072 Standards Committee for AC V2Grid, alternating current V2G, which will allow the onboard charger of an EV to transfer power from its battery pack to the grid. EVs can also transfer power through a DC charger back to the grid, and that's called DC, direct current, V2G. I believe Pacific Gas and Electric will be conducting large-scale pilots in the next year or so, to demonstrate capabilities of V2G and the aggregate. Primarily DC, but potentially also AC.

Jason Price:
Well, thanks for that level setting.

Jason Price:
Back to the topic at hand. We know that the EV market is growing, but will it really grow at the necessary scale to provide such grid service?

Charlie Botsford:
Well, one EV doesn't provide a whole lot of energy storage. Or, does it? Actually, a single EV with a 60 kilowatt hour battery pack could power a house for several days, in an emergency outage. Stories abound regarding the cold snap in Texas last winter, and those with Tesla vehicles able to ride out the storm in their garage.

Charlie Botsford:
The US now has approximately two million EVs, without almost a million in California alone. By 2030, we're talking 100 gigawatts of power capacity and half a terawatt hour of energy storage, just in California alone, via EV batteries. That's a lot of power and a lot of energy.

Charlie Botsford:
For bulk purposes, this is essentially infinite hours of available storage to enable renewables penetration onto the grid. To provide additional power and storage, just besides EVs, we'll have plenty of inexpensive retired EV batteries that can be used for grid services. You don't really want to scrap old EV batteries, so this application is a win-win, considering reuse is much better than automatically land filling old battery packs. The valuation for grid services is compelling. It's a lot less expensive than brand new batteries, the batteries are very high quality. And, even though they've reached their end of life in a vehicle, they still have plenty of life available for grid services. And again, they're very inexpensive that way.

Jason Price:
Well, okay. That's the utility perspective. What about the EV market? Is this type of strategy an extra consideration that automakers will have to factor in when building their batteries? Or, does this actually provide a useful opportunity from their perspective?

Charlie Botsford:
In my discussions with EV manufacturers, and as the guys that we've been dealing with forever and ever, Honda, Ford, GM, Volkswagen, this actually provides a great opportunity. Smart charging, or V1G, has zero impact on an EV battery because you're just charging it. You might be charging it at a different rate, but it's just one direction charging. And, it's 100% roundtrip efficiency because there's no roundtrip, it's just one-way charging. That's easy. And again, as I said before, it's 90% of bulk grid services you can do with just one direction smart charging.

Charlie Botsford:
For V2G charging, the system roundtrip efficiency loss is about 10 to 15 percent, due to power transformation. You have to go from DC to AC, and back to DC. So the vehicle manufacturers might actually need to replace their current type of onboard charger with a bidirectional charger, to do AC V2G. And then, DC V2G, you just do that with an off board, regular DC charger.

Charlie Botsford:
So from a vehicle manufacturer perspective, not really that big a deal. There's a lot of work, a lot of standards works in development at the utility level, to make sure that all of this happens.

Jason Price:
Interesting. Well, Matt, certainly jump in here as an EV driver. But for owners of EVs, whether it's personal vehicles or corporate fleets, how will they be compensated? And, what exactly goes on with the battery here? Is there a degree of degradation that they have to experience?

Charlie Botsford:
Matt can chime in here as well. But EV drivers, I think they might have potential pack degradation with V2G because you're taking power back out of the power, and you're cycling it. Would that cause degradation? But, actual data on new generation packs really shows little degradation.

Charlie Botsford:
A current program in the Netherlands has demonstrated a high value of compensation to EV drivers for V2G services, in a market environment. Right now, market V2G services, EV drivers getting quite a bit of money for that service and very little pack degradation. I think we'll see market aggregators who enlist EV driver and fleets to bid for grid services, just like we see for natural gas power plant for wind farm. In fact, I think I just saw an article about Tesla going into the Texas market recently. Maybe not as Tesla vehicles, but certainly for energy storage.

Matt Chester:
I mentioned at the top how I was a little surprised that my utility wasn't one that was jumping in more to be engaging on the EV drivers side. I've asked about, "Oh, is this something you're looking at," I've asked about time of use rates, and really heard that that's not something they have on the docket right now. I don't know if it's because it's a smaller utility or they're waiting to see how other people do it first.

Matt Chester:
But I'm curious, Charlie, is that a hesitation that you think is common? And, is there a specific reason behind it?

Charlie Botsford:
Utilities are a pretty conservative bunch and they like to see other utilities do things. On the West coast, we've got the three IOUs with Edison, and PG&E and San Diego Gas and Electric really getting hundreds of millions of dollars from CPUC to do these pilot programs. I think a lot of utilities are just taking the wait-and-see attitude.

Charlie Botsford:
Plus, it takes a while for things to work through the regulatory environment. State level rules and standards. A year, two years, before things settle up. But, we'll see that going. And then, all of the utilities are going to hop on board with that the next three to five years.

Jason Price:
Charlie, let's talk about the Presidential Administration, and its position and investing here in clean energy, especially his campaign pledges and such. And of course, Jennifer Granholm, the Secretary of Energy, who also seems to be all-in with electric vehicles, especially coming from the state of Michigan.

Jason Price:
The question is basically, with the influx of Federal spending from infrastructure policies, COVID relief and more, how can those funds be put to use in a positive way for this type of grid-tied EV storage?

Charlie Botsford:
Energy Central has had this series of articles by Doug Houseman, that says, "If I were king," and I love that series of articles ... "If I were king, I would advise the Administration to focus EV charging infrastructure funds on two primary areas. One would be long dwell time charging," which is really the foundation of how EVs currently get charged and how they'll get charged in the future. This is at single family residential, multi-unit dwelling like condo complexes and apartment buildings, workplaces, depot charging. Depot charging, like for school buses. That's number one. That's long dwell time charging, primarily overnight, workplaces during the day. And then, number two would be corridor DC fast charging for light, medium and heavy duty vehicles.

Charlie Botsford:
Those are the two primary categories that I would advise the Administration go all in. Those are the two that get the biggest bang for the buck, as far as really getting EV infrastructure out there that needs happening.

Charlie Botsford:
The first category provides the greatest opportunities to supply grid services, as it turns out. For instance, overnight charging for school buses, and even during the day. So school buses, I don't know if you know, but they go out in the morning and they go out in the afternoon. But in the middle of the day, there's plenty of opportunity for them to do V2G services.

Charlie Botsford:
The second category enables true equivalency with conventional internal combustion vehicles. That's the old thing about you go out and you want to drive across the country, could you do it? Well, you actually can nowadays. Maybe it was a little bit sketchy 20 years ago. But, the more and more DC fast charging that gets out there, like Tesla's 20,000 port super-charger network just in the US alone is amazing, and EV Electrify America, and EV Go and some of the other networks. All of that with DC fast charging really puts electric vehicles on the same footing as gasoline powered vehicles.

Charlie Botsford:
I think those two scenarios are where the Administration really needs to put their money. Our money, actually. My money.

Jason Price:
Well, I appreciate the shout out to Doug Houseman, who's actually our guest on episode 35. Yeah, he has a lot of rich ideas and thoughts to share in this space. Yeah, thanks for recognizing him.

Jason Price:
So Charlie, all of this sounds compelling in theory, but are the strategies being put to use in practice anywhere today? What are the latest projects pushing the limit?

Charlie Botsford:
Sure. Well, way back in the '90s, I worked with a guy named Dr. Alec Brooks. Really smart guy. In the late '90s, he was with AC Propulsion and demonstrated V2G capabilities to the California Air Resources Board. And by the way, he also demonstrated up and down frequency regulation using just mere V1G smart charging, unidirectional smart charging. That was all way back, I think 1998, when he did that demo to California Air Resource Board.

Charlie Botsford:
The really impressive capabilities have been demonstrated over the last, really, quarter century. Real world programs have cropped up over the last couple of years, showing the actual market application, that market in the Netherlands I mentioned earlier. It's exciting times for those of us who've been around long enough to see the slow but steady developments now coming to fruition.

Jason Price:
Yeah, that's great. Well, Charlie, now we want to step back from the EV battery conversation, and learn more about you and who you are. We do that in our patented Lighting Round, which consists of a couple of quick questions that require a response of just one word or one phrase. Are you ready?

Charlie Botsford:
I'm ready, go for it.

Jason Price:
All right. What's been your all-time favorite vacation destination?

Charlie Botsford:
Australia.

Jason Price:
What did you want to be when you were growing up?

Charlie Botsford:
Oddly, an engineer. I don't know why I didn't want to be a doctor or an astronaut. My dad was a master mechanic who could fix anything and I suppose that's probably what inspired me to be an engineer.

Jason Price:
What book, movie or TV show do you think you've revisited the most, with repeat viewings or readings?

Charlie Botsford:
Highlander, not even close.

Jason Price:
If you could have one meal for the rest of your life, what would it be?

Charlie Botsford:
Taco flavored Doritos, but I'm not sure that qualifies as an actual meal.

Jason Price:
And, what are you most inspired by?

Charlie Botsford:
Well, okay. It sounds stock, but the ingenuity of our fellow humans to solve problems is really impressive. Again, I think back to my dad who could fix anything and my mom who was a beautiful writer.

Jason Price:
Well done. Charlie, we appreciate you allowing us to peel back the curtain a bit for us. For being a good sport with our Lighting Round, you've earned the right to the final word of the podcast.

Jason Price:
So knowing that the key utility decision makers across the country are listening to what you have to say, what's your immediate call-to-action to them? And, how can they start putting action behind these ideas?

Charlie Botsford:
Well, over the years I've come to respect market forces and look for the sign of a valid business model behind technology applications. Just because you can make a prototype work doesn't mean the technology can be economically viable. Likewise, I think utilities should search for ways to build a future grid for stability and resiliency, based on technology that's economically sound and market tested.

Jason Price:
That was great. And, thank you for this wonderful conversation, Charlie. I know that our audience will have questions and comments on this fascinating topic so we encourage them to head to Energy Central. I also want to thank you, Charlie, for being an active member of the community and sharing your wisdom throughout.

Jason Price:
You'll find exclusive bonus clips of parts of today's conversation that couldn't fit into the final cut of the episode, so it's accessible only to registered members of the Energy Central community.

Jason Price:
Charlie Botsford, thank you so much once more, for your sharing your insight with us today, on today's episode of the podcast.

Charlie Botsford:
Well, thank you, Matt, and thank you, Jason. Really appreciate the time.

Jason Price:
Once again, I'm your host, Jason Price. Log in and stay fully charged in the discussion by hopping into the community at energycentral.com. See you next time at the Energy Central Power Perspectives Podcast.

 


About Energy Central Podcasts

The ‘Energy Central Power Perspectives™ Podcast’ features conversations with thought leaders in the utility sector. At least twice monthly, we connect with an Energy Central Power Industry Network community member to discuss compelling topics that impact professionals who work in the power industry. Some podcasts may be a continuation of thought-provoking posts or discussions started in the community or with an industry leader that is interested in sharing their expertise and doing a deeper dive into hot topics or issues relevant to the industry.

The ‘Energy Central Power Perspectives™ Podcast’ is the premiere podcast series from Energy Central, a Power Industry Network of Communities built specifically for professionals in the electric power industry and a place where professionals can share, learn, and connect in a collaborative environment. Supported by leading industry organizations, our mission is to help global power industry professionals work better. Since 1995, we’ve been a trusted news and information source for professionals working in the power industry, and today our managed communities are a place for lively discussions, debates, and analysis to take place. If you’re not yet a member, visit www.EnergyCentral.com to register for free and join over 200,000 of your peers working in the power industry.

The Energy Central Power Perspectives™ Podcast is hosted by Jason PriceCommunity Ambassador of Energy Central. Jason is a Business Development Executive at West Monroe, working in the East Coast Energy and Utilities Group. Jason is joined in the podcast booth by the producer of the podcast, Matt Chester, who is also the Community Manager of Energy Central and energy analyst/independent consultant in energy policy, markets, and technology.  

If you want to be a guest on a future episode of the Energy Central Power Perspectives™ Podcast, let us know! We’ll be pulling guests from our community members who submit engaging content that gets our community talking, and perhaps that next guest will be you! Likewise, if you see an article submitted by a fellow Energy Central community member that you’d like to see broken down in more detail in a conversation, feel free to send us a note to nominate them.  For more information, contact us at community@energycentral.com. Podcast interviews are free for Expert Members and professionals who work for a utility.  We have package offers available for solution providers and vendors. 

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See Below for an Exclusive Bonus Clip: Available only on EnergyCentral.com for our Community Members

 

Discussions
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Bob Meinetz's picture
Bob Meinetz on Sep 14, 2021

"For V2G charging, the system roundtrip efficiency loss is about 10 to 15 percent, due to power transformation."

Charlie, what's your source for this figure? I assume for "power transformation" you're adding up idealized losses for bi-directional inversion and internal resistance. If so, there are many pieces missing from the puzzle: doubled transmission losses, increased battery resistance due to low nighttime temperatures / battery age, among others.

Though the study below examines how poor efficiency affects its economics, V2G will be storing the current grid mix, and electricity lost will require replacement. Thus, we can expect V2G to increase CO2 emissions by a corresponding percentage.
 

"Highlights - Efficiency is critical for V2G economics, but data were not previously available.
A recent study filled this void, finding roundtrip efficiency of 53%–62%.
Existing V2G economic analyses ignore losses or assume much higher efficiencies.
Electricity losses can offset >50% of V2G revenues from frequency regulation."

Comments on “Measurement of power loss during electric vehicle charging and discharging” – Notable findings for V2G economics

 

Charles Botsford, PE's picture
Charles Botsford, PE on Sep 16, 2021

Hi Bob,

You're right to question what someone means by "roundtrip efficiency". Definitions matter. For example, the coulombic efficiency of charging a lithium battery depends on the charge rate. At high, fast charge rates (like at a Tesla supercharger or Electrify America station), the battery charging efficiency can be as low as 98%. At low, trickle charge rates (think overnight charging in your garage), the efficiency is greater than 99.5%. That's the battery portion. 

 

Next up is the power electronics portion. For V1G, or unidirectional charging, you only have to rectify grid AC power to the DC power that charges the battery. Good AC-DC rectifiers (the on-board charger in your EV, or OBC) are in the 97% efficiency range. Thus, V1G has a single-trip efficiency in the 96% or better range from the grid into your battery when you charge your EV overnight. Personally, I like V1G unidirectional smart charging because you can supply all the grid services you need, even up and down frequency regulation. For wide grid energy storage, V1G from EVs will handle pretty much all the grid services we need (c. 2035 timeframe). What V1G doesn't handle completely are local services.

 

Now we get to V2G. You need an extra trip to push the power back into a house (V2H), a building (V2B), or the grid (V2G). For that, you have to convert the DC energy from the battery back through a DC-AC inverter to kick it onto the grid. For AC V2G, A good DC-AC inverter going from say 500VDC back to 240VAC is around 97% efficiency, but who knows what the auto OEMs will do when they combine functionality of the EV's on-board charger into a four-quadrant bi-directional combo rectifier/inverter? Thus, the roundtrip efficiency of this process could be well over 90%, probably more like 93%. 

 

DC V2G has a similar roundtrip efficiency as AC V2G, you just invert the DC power through a stationary charger instead of an OBC, usually to 480VAC. Lots of DC V2G demo projects use the Nissan Leaf CHAdeMO port to connect to the grid. The electric utilities don't hate you nearly as much doing it this way as via AC V2G. For AC V2G, the OBC/EVSE and communications protocol need to comply with SAE J-3072, IEEE1547-2018, and if you're really rambunctious, California Rule 21. SCE is conducting V1G pilots, while PG&E is conducting V2G pilots.

 

Defining a different system boundary could yield a different "roundtrip efficiency" percentage.

Bob Meinetz's picture
Bob Meinetz on Sep 17, 2021

Charlie, V1G is not a problem. On any grid in the U.S., EVs reduce carbon emissions compared to internal combustion cars.

V2G is a completely different animal - we're unnecessarily wasting a significant fraction of every kWh that's stored before it ever reaches customers:

• Again - your calculation relies on idealized specs from manufacturers - the best of the best, under ideal circumstances. That's a situation that never, ever occurs in practice.
• You're not including transmission losses: stepping down from high-voltage network voltages to distribution voltages (where the bulk of losses occur), then back up again.
• You're ignoring real-world properties of Li-ion batteries mounted in cars - ones that are notoriously sensitive to temperature and age.
• From a practical standpoint, we're assuming electricity customers will be willing to accept a permanent reduction of their car's battery capacity, over time, due to increased cycling. We're assuming customers will accept the uncertainty of never knowing how much range will be available from their car when they need it - all to help their utilities meet their quarterly profit forecasts (?). 

The empirical study I've provided demonstrates that in practice, losses are at least 25% greater than simply summing those provided on manufacturer spec sheets. Unlike switching from internal combustion to electric vehicles, V2G can only make the grid dirtier and increase carbon emissions. Whether that's in 2021 or 2051, that's going backwards.

Charles Botsford, PE's picture
Charles Botsford, PE on Sep 20, 2021

Hi Bob,

It's all about how you define your system boundary. The beauty of EV charging is that you don't have to go all the way back to the transmission system of 760kVDC. In fact, if you're patient enough, you can charge your EV at night on a 120VAC outlet and get 40 miles the next day. Likewise, most DC fast charging stations take 480VAC three-phase grid power as input. The common thread is that this is a relatively low voltage venture that barely affects the distribution system, let alone transmission. If you're able to reduce load at the end of the line, you provide system value all the way upstream.

I actually have a good deal of real world empirical experience with battery charging and power electronics. I completely agree with you about people quoting theoretical specs. In fact, we used to have a saying, "There are liars, damn liars, and battery suppliers." That saying is true for a good number of other industries. 

I have witnessed battery chargers routinely exceed 95% efficiency under real world conditions. Today's inverters and rectifiers aren't a stretch at 97%. But let's take your "25% greater" loss statement. My original statement was that the roundtrip efficiency is in the range of 85-90%. I'll stick to that, even knowing that I've witnessed real life conditions that exceed efficiency.

As for empirical studies. I'm worked on the following EPRI/CEC program:

Distribution System Constrained Vehicle-to-Grid Services for Improved Grid Stability and Reliability

https://ww2.energy.ca.gov/2019publications/CEC-500-2019-027/CEC-500-2019-027.pdf

 

Bob Meinetz's picture
Bob Meinetz on Sep 21, 2021

Charlie, no - it's not all about how you define your "system boundary". It's comparing two very distinct scenarios:
 

1) the efficiency of transmitting the direct output of a power plant to point of use, to
 

2) the efficiency of splitting the direct output of a power plant to thousands of locations at various distances from the plant, then stepped down to distribution circuit voltage, then to service voltage, then rectified and stored in thousands of different EV batteries, at various stages of capacity fade and resistance loss (avg 50% increase over three years), then inverted and frequency-corrected to three-phase AC, then stepped up to transmission voltage and transmitted to point of use - again.
 

The document at your link, assembled by entities which stand to benefit from selling V2G, is hardly an empirical study. Measurement of efficiency is non-existent, and its V2G "implementation" involves three vehicles? Please. It's the same aspirational nonsense I would expect from the attorneys, biologists, "communication designers", and other assorted policy advocates who make up the California Energy Commission - people who couldn't explain the difference between AC and DC if their life depended on it.

Like the California Public Utilities Commission, the California Lands Commission, the Air Resources Board, etc., they're ideologues appointed by California's Governor to rubber stamp his policy objectives. Nothing more. Authors even revel in their confirmation bias:

"The diverse nature of California’s distribution system necessitates that similar studies be
conducted in the future for a wider range of selected scenarios across broader types of
distribution system segments. Performing such studies across more scenarios, and analyzing
hundreds of actual vehicles and their charging behavior across California, will ensure that V2G benefits are thoroughly validated."

When all was said and done, even the CEC felt the need to wash its hands:

"DISCLAIMER
This report was prepared as the result of work sponsored by the California Energy Commission. It does not necessarily represent the views of the Energy Commission, its employees or the State of California. The Energy Commission, the State of California, its employees, contractors and subcontractors make no warranty, express or implied, and assume no legal liability for the information in this report; nor does any party represent that the uses of this information will not infringe upon privately owned rights. This report has not been approved or disapproved by the California Energy Commission nor has the California
Energy Commission passed upon the accuracy or adequacy of the information in this report. Honestly, Governor Newsom made us release this crap for public consumption. Sorry."

Charles Botsford, PE's picture
Charles Botsford, PE on Sep 21, 2021

Hi Bob,

The system boundary for the efficiency of your scenarios 1 and 2 is the same from the point of generation (e.g., power plant) to point of use. The point of use is a business, an industrial facility, a house, etc. In other words your scenarios 1 and 2 are identical up to the point of use. 

You take scenario 2 further to include EVs, which is a great idea. For unidirectional smart charging (V1G), the efficiency loss is about 5%, which includes the on-board charger (rectifier) loss and the coulombic efficiency loss of charging the battery. I like V1G because this is the farthest reaching use for EVs as energy storage for the grid. V1G has the potential to handle nearly all wide grid energy storage requirements. The reason V1G works so well is that it provides all the types of grid services other energy storage resources do (e.g., battery farms), including up and down frequency regulation.

V1G, however, isn't a great solution for local issues, for example a public safety power shutoff (PSPS) event at a business or a residence. For that circumstance, energy storage that can export power back to the house or business is necessary.

For bi-directional power flow (V2G), whether AC V2G (mobile) or DC V2G (stationary) the reverse loss to the "grid" is about the same as the forward loss from V1G, which means the roundtrip loss is on the order of 10% or has a roundtrip efficiency in the range of 85-90%. You argue that the loss must include taking the power all the way back through the substation, back through the transmission line, and all the way to the power plant. I disagree. By expanding the system boundary this way, you envision the grid as a unidirectional monolith -- i.e., the electrons flow only one way. Electrons flow in the direction of highest to lowest potential. At the power plant they flow to the transmission line and down to the substation -- one way. Once you get to the local distribution circuits, especially to the 480VAC level, electrons do whatever you tell them to do. You just have to convince them with a little potential manipulation and some power electronics.

Whether it's V1G or V2G or pumped storage from a dam, the idea of energy storage to assist the grid is the same: assist the power generation source overcome its dispatchability and intermittency issues. Nuclear power plants have great capacity factors, which means they don't need much help with either of these, but they can't ramp up and down quickly or meaningfully. That's something energy storage can help with, especially if we want to get rid of peaker turbines. Coal and natural gas plants have mediocre capacity factors, wind has so-so capacity factors (depends whether it's land-based or offshore), and solar has a terrible capacity factor, which is why it has to be paired with energy storage to be useful at all to the grid.

Finally, your comment regarding the CEC report is off base, unless you believe all CEC reports are a waste of taxpayer money. CEC routinely requires the disclaimer placed on all technical reports they sponsor.

 

Bob Meinetz's picture
Bob Meinetz on Sep 21, 2021

"For unidirectional smart charging (V1G), the efficiency loss is about 5%..."

If only we could trust EV drivers to park their cars in garages that are climate-controlled at 72°F. At 50°F, efficiency loss is ~10%; at 86°F, it's twice that.

"By expanding the system boundary this way, you envision the grid as a unidirectional monolith -- i.e., the electrons flow only one way."

Electrons only flow one way over DC transmission. >90% of US transmission is AC, where electrons flow both ways. They move back and forth, changing direction at 60 Hz.

"Whether it's V1G or V2G or pumped storage from a dam, the idea of energy storage to assist the grid is the same: assist the power generation source overcome its dispatchability and intermittency issues."

Interesting perspective. But the purpose of energy storage is not to assist the grid, it's to address the shortcomings of renewable energy. For fifty years the U.S. grid was remarkably stable with no storage at all.

"Nuclear power plants have great capacity factors, which means they don't need much help with either of these, but they can't ramp up and down quickly or meaningfully."

Though ramping up and down quickly is necessary to accommodate solar and wind, the subtle curves of customer demand are well within the load-following capability of modern nuclear plants. At Gen 3 German and French plants, for example, reactors are ramped up and down all day long:



Granted, load-following can be hard on older plants in the U.S. But instead of flying the equivalent of 1970s-era DC-10s in our fleet, maybe it's time to upgrade to new Airbus A-320s? And since they're creating all of these other problems, cart solar panels and wind turbines off to the landfill?
 

"CEC routinely requires the disclaimer placed on all technical reports they sponsor."

Why? If they won't stand behind the reports, they shouldn't be forcing taxpayers to pay for them!

Ann Marie O'Connell's picture
Ann Marie O'Connell on Sep 20, 2021

The single largest impediment to widespread 2-way EV-to-grid connections is and almost certainly will continue to be many EV makers need to protect the reliability and service life of the vehicle battery. Right now, you void the warranty on all Teslas and some other manufacturer's EVs if you establish a bi-directional power connection to your vehicle's battery even once.

And then there's the Ford F-150 Lightning, that has the controls needed to make that connection standard, and plans to sell the necessary cable as an optional accessory.

Charles Botsford, PE's picture
Charles Botsford, PE on Sep 20, 2021

Hi Ann Marie,

I haven't found the detailed specs on the Ford F-150 Lightning on-board charger (OBC). It lists the capability to export power for applications such as construction. Possibly it could also supply power to a house. I doubt it has the capability to export power to the grid. In fact, I know of no commercially available EV in the US market that has an OBC with that capability. To comply with SAE J-3072, IEEE 1547-2018, and California Rule 21, the OBC would have to communicate via IEEE 2030.5, be four-quadrant, and have the capability to supply reactive power. 

DC V2G is a much easier venture and has been demonstrated abundantly by hooking the CHAdeMO port of a Nissan Leaf to a bi-directional stationary charger. One charger manufacturer now manufactures such a beast with a provisional UL 9741 listing. 

Ann Marie O'Connell's picture
Ann Marie O'Connell on Sep 22, 2021

You're correct that Ford's F-150 Lightning is set up, by design, with an inverter that allows the vehicle battery to export power to a house (or other building) that is disconnected from the grid (islanded) during a power outage, not to export power directly to the distribution grid.  However, a small microgrid might well be adaptable to using one or more Ford Lightning batteries as a power source while that microgrid is operated independently. 

 As far as I have found, Ford is the only EV manufacturer that does not explicitly forbid vehicle owners from making that kind of connection to their vehicle.  If vehicle OEMs currently forbid using a car's battery for back-up power on ones' own property because of claimed ill-effects that on both safety and battery pack life, why do you think that OEMs or vehicle owners would want to build in the necessary software and hardware connections to hook those batteries to a utility's grid?   Retrofit kits would be even worse from a safety and reliability point of view. 

Given the recent rash of battery fires with Chevy's Bolt and Tesla's Model Plaid vehicles, the idea of using EVs connected to "smart charging" stations when not in use to buffer intermittent generation from wind and solar systems strikes me as terribly dangerous.  I think it's very unlikely to be approved for general use in less than a decade, even if Pete Buttigieg and Jennifer Granholm conspire to rush through changes to  existing regulations to allow experiments at a state or region-wide scale.   

Charles Botsford, PE's picture
Charles Botsford, PE on Sep 23, 2021

Hi Ann Marie,

Take care to distinguish terms of art. "Smart charging" for the past several years, and currently, refers to unidirectional (V1G) charging. I suppose smart charging will someday refer to V2G when that becomes prevalent, but V2G isn't yet, so when people talk about "smart charging" they currently refer to the act of varying the rate that you charge an EV. That said, V1G smart charging is a powerful tool that can perform many types of grid services from brute force demand response (dialing back the charging rate), to up and down frequency control (monitoring the wide grid frequency and modifying the charging rate accordingly). Up and down frequency control is especially suited for EVs because the on-board chargers (at least the wide variety we tested) can respond within four seconds, which is about the same response you get from a utility-scale battery farm and an order of magnitude faster than a peaker turbine.

All this is to say that you shouldn't get sidetracked by the notion of V2G, which will someday be a nice niche application. You should follow the 80/20 rule and focus on "smart charging", or V1G, which is safe (except for that little Bolt thing you mentioned), efficient, and extraordinarily powerful in providing grid services. GM will get their battery supplier back on track and the instance of EV battery "events" will get back to the current ratio of 1:100 EV to ICE vehicle events (corrected for vehicle population) that Musk quotes, or whatever it is. I try not to focus on politics in technical discussions. For me, keeping the technical straight and accurate is a chore unto itself. I'm an engineer and try to dive into real statistics rather than scare tactics that evaporate under scrutiny.

Jim Stack's picture
Jim Stack on Sep 20, 2021

I think V2G is one of the many features that all electric vehicles should have. It has been demonstrated at the University of Delaware for over 10 years. They use the ACPropulsion made MINI-E EVs. They worked out a tariff with the local power company and got paid $1,200 a year just to be plugged in EVen when not sending any power, just on standby. They found that letting the power company pull just a low power amount would actually help the battery life. 

     All ACPropulsion made vehicles and controllers have V2G bidirectional ability built into them. The 1st Tesla Roadsters that used their controllers had that feature but Tesla never told about it. Then Tesla said no one was interested in it. Now that Tesla batteries have been shown to last 20 years at only 10% loss of capacity they might charge their minds with the 4680 battery. The Cyber truck seems to have 120/240 power output. 

Charles Botsford, PE's picture
Charles Botsford, PE on Sep 20, 2021

Hi Jim,

I agree that AC V2G should be an EV feature, but I doubt it will be for several years. For one thing, a lot of development has to happen on the utility side, especially with California Rule 21, IEEE 1547-2018, and communications protocols (e.g., IEEE 2030.5). From an OEM perspective, including a bi-directional on-board charger in the EV is the wrong direction from cost and system complexity. They hate things like that. Eventually, they'll likely do it, but how soon is the question.

Now DC V2G is another matter. That's an easy one for the OEM and utility folks to grasp. This is going great guns with electric school buses and and other medium- and heavy-duty electric fleets. 

You're also right about capacity loss. All indications are that the capacity loss, even with the V2G fleets in Europe, is minimal. The value of the V2G market services in Europe are very compelling, similar to the UD work you mention.

As for the Tesla Cyber truck or the Ford F-150, exporting power for on-site use or to a house is a much different venture than back to the grid. The on-board charger (OBC) must be four-quadrant and have the capability to supply reactive power to comply with SAE J-3072. I have my doubts that either vehicle has that level of OBC.

Bob Meinetz's picture
Bob Meinetz on Sep 22, 2021

"You're also right about capacity loss. All indications are that the capacity loss, even with the V2G fleets in Europe, is minimal. "

Not all indications, Charlie. Here's a link to two studies - one that found:

"current V2G models would be detrimental to the lifetime of an EV battery, potentially shortening battery lifetimes to less than five years and increasing their capacity loss by 75% over an 18-month period."

and another that found:

"intelligent V2G could actually reduce the capacity and power fade of an EV battery by up to 9.1 and 12.1% respectively."

What is "intelligent V2G"?

‘optimised’ or ‘smart’ V2G systems — designed to work more responsively and efficiently, and to rely on prognostic battery degradation models to limit the amount of energy that could be traded."

Translation: "V2G is probably going to destroy your EV's batteries in five years. But optimised, smart technology with prognostic battery degradation models, available in some renewables future-now when all conditions are perfectly optimised, might actually slow your capacity loss slightly."
 

Thanks, but this EV owner will pass!

Bob Meinetz's picture
Bob Meinetz on Sep 22, 2021

"Now that Tesla batteries have been shown to last 20 years at only 10% loss of capacity..."

Oh, really? Tesla built its first production car, the Tesla Roadster, in 2009.
2009 + 20 = 2029

Careful, you're slipping into future-now again - the land where renewables dreams come true!

Charles Botsford, PE's picture
Charles Botsford, PE on Sep 22, 2021

Hi Bob,

Good catch. Capacity fade is a complex subject. Mostly, the discussion centers around kWh capacity. Some battery chemistries have excellent kWh capacity, such as lithium titanate and lithium iron phosphate (LPO). Tesla is moving to LPO for some of their lower end models because it's cheap, doesn't catch fire, and lasts forever from a kWh throughput perspective (3000 to 5000 full depth-of-discharge cycles typically). People who model capacity fade perform highly accelerated life testing (HALT), which means cycling the battery in a thermal chamber at high and low temperatures over all kinds of conditions and charge rates.

Performing HALT work also helps understand the other type of capacity fade, which is the calendar life of the battery. How do you know whether a battery, even if it's not cycled much, will last 20 years? Thermal testing will give an indication, as will EV batteries used in the wild for many years. One example is a 1kWh module of LTO (lithium titanate) cells we had access to. They'd been sitting in a warehouse for several years and we figured they were toast. Not expecting much, we ran through the standard conditioning routine and eventually the module came back to nearly 100 percent capacity (and very low internal impedence), but that's LTO, which is an amazing chemistry. Boy, were we surprised.

I've reviewed technical reports on capacity fade under real life conditions with EVs monitored up the wazoo. One of the European studies (EVs running in the streets under normal conditions) listed a 2% capacity fade after two years of testing, including V2G services. 

Kevin Cameron's picture
Kevin Cameron on Sep 21, 2021

At #HEMBUS (http://hemb.us) we are assuming they don't have a choice, EVs are both a problem and a solution for the grid operators, but they exist on the other side of the meter, outside their control.

Electrifying transport will triple the load on the grid, using the EVs as storage is part of solving that problem, the other part is just not using the grid, and using the EVs to move energy.

Charles Botsford, PE's picture
Charles Botsford, PE on Sep 22, 2021

Hi Kevin,

Utilities currently use EVs at workplace and other locations to perform simple demand response services in the California IOU market and other markets as well. The IOUs send an OpenADR 2.0b signal to an aggregator who then sends a different signal (OCPP 1.6 or IEEE 2030.5) to the individual EVSEs they control. It's a brute force way to shut off load during a hot August afternoon in Southern California. Though the EV charging infrastructure (EVSEs and DC chargers) are often behind the meter, the utilities and grid operators have great control. It's a pretty robust ecosystem when you include the aggregators and market forces, and of course the EV driver, who has the final say about how her EV battery is charged.

Kevin Cameron's picture
Kevin Cameron on Sep 28, 2021

The #HEMBUS plan is to buy peoples' EV batteries for them, and then make sure they make money for everybody. Most drivers won't care how the battery is being used as long as it is sufficiently charged when needed. The IOUs will have to deal with me as a VPP rather than the vehicle/home owners.

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