Energy from electric cars could power our lives — but only if we improve the system
Two apparently contradictory studies come together with recommendations
Oxford, November 22, 2017 – Power stored in electric cars could be sent back to the grid – thereby supporting the grid and acting as a potential storage for clean energy – but it will only be economically viable if we upgrade the system first. In a new paper in Energy Policy, two scientists show how their seemingly contradictory findings actually point to the same outcome and recommendations: that pumping energy back into the grid using today’s technology can damage car batteries, but with improvements in the system it has the potential to provide valuable clean energy – and improve battery life in the process.
Electric cars store excess energy when they are idle. Vehicle-to-grid (V2G) technology makes it possible to transfer that energy back to the grid when the car is not being used. This energy could help regulate the frequency of the electricity supply, reduce the amount of electricity purchased at peak times and increase the power output of the system.
Two recent studies, one by Dr. Kotub Uddin at the University of Warwick in the UK and the other by Dr. Matthieu Dubarry at the Hawaii Natural Energy Institute, seem contradictory, with one suggesting that V2G degrades car batteries and the other that it improves battery life. But the two scientists worked together to look at how their studies overlap, showing that they actually come to the same conclusion.
“Although both our papers seem contradictory, they are actually complimentary,” said Dr. Dubarry. “V2G is not going to be easy, but, if done properly, it has a chance to make a difference for both utilities and electric vehicle owners. We need more research to understand the process better and benefit from the technology.”
The two authors agreed that in order to be economically viable, V2G has to be optimized between the requirements of the car owner, the utilities and the capability of the grid. In other words, the needs of the different people and systems involved have to be balanced. The question then became ‘can this technology be profitable?’
The previous studies had different approaches to answering this question: Dr. Dubarry showed that using today’s V2G technology can be detrimental to the car battery, while Dr. Uddin found a smarter grid would make the process economically viable, and even improve the battery. In the new paper, they critiqued each other’s work and found shared conclusions. With improvements to the system, V2G could actually improve electric car battery life and be profitable for everyone involved.
Measuring the impact of the technology on the battery is challenging. After two years of analyzing lithium-ion batteries, Dr. Uddin and his team developed an accurate battery degradation model that can predict the capacity and power fade in a battery over time under different conditions, such as temperature, state of charge and depth of discharge. That means the model can predict the impact of V2G on battery health. Using this model, they created a smart grid algorithm that shows how much charge a battery needs for daily use and how much can be taken away to optimize battery life.
Dr. Uddin says funding is needed to develop new testing standards and control strategies to guide policies that support V2G. One key element to improving the system, he says, will be the measurement of battery degradation.
“The metrics used to define battery degradation may also impact the optimization process,” he explained. “A critical component is who is responsible for estimating battery degradation? Utilities are currently taking the lead in the EU, but it might be more economical for the battery manufacturers or car manufacturers to do it. In this case, standards need to be written which define what we mean by ‘state of health’ when it comes to batteries, and the metrics that are used to determine it.”
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The paper:
“The Viability of Vehicle-to-Grid Operations from a Battery Technology and Policy Perspective” by Kotub Uddin, Matthieu Dubarry, and Mark B. Glick. (DOI: 10.1016/j.enpol.2017.11.015). The article appears in Energy Policy (November 2017), published by Elsevier.
Link to the paper: https://doi.org/10.1016/j.enpol.2017.11.015.
run the numbers and it doesn’t add up, like all ‘renewable’ ‘new age’ technology…
wanna talk about all the negative externalities
of fossil fuel use?
i didn’t
think so
crackers345 – two things, quit smoking crack and being late to the discussion.
Having the last laugh doesn’t make you superior, just makes you slow on the uptake.
“This is why I am keen on a PHEV 4×4 Jeep. Just autostart up the micro diesel ICE generator in the Jeep when the voltage drops and plug yourself into the Jeep. Imagine towing that down to Arizona in the winter behind the RV.”
Now that is funny, on so many levels.
First, the solution to making electricity with fossil fuels is making electricity with fossil fuels.
Second, what can you do with a ‘micro diesel ICE generator’? Charge your batteries so you can start your micro ice again.
People just do not understand the power requirements of things and why that makes things very heavy. The inverter/charger in our motor home is sized to charge the batteries in a couple of hours at 2500 watts. Replacement cost is $2000+
Who want to run a generator all day? Our motor home Onan 6500 watt generator is sized to charge the batteries and run two A/C units when it 100+ degrees F in the Arizona desert.
The problem with charging our motor home batteries with other sources of electricity is line loss. As voltage drops, the battery charger output. On the installed generator, it charges at 120 amps dc. At the house, we get 90 amps. Our micro generator (can be lifted with one hand) and some campgrounds with an extension cord we get 15 amps dc charging.
Making 120 Vac with the inverter from 12 vdc has similar issues. Using the microwave or coffee maker puts a big load on the battery. Depending on the battery charge, the inverter might trip on low voltage.
Of course there is always the convenience of propane. Before electric coffee makers, we boiled water.
Who knew, right?
I suspect V2G advocates only know how to order coffee at Starbucks.
V2G is very bad solution looking for a problem.
The power industry does not have a problem providing power to match load. The environmental impact is insignificant as required by regulations. This is not to say politician are not equally good at manufacturing fake problems.
The power industry uses automatic control systems at steam plants to provide power to match load. It works very well.
Modern motor homes have a V2G. The inverter/charger in our motor home charges the battery when a source of 120 Vac power is available. When no ac power, the inverter supplies 120 Vac 60 hz to the mini motor home grid from 12 Vdc batteries. It load follows very well.
It is sized to charge the batteries in a couple of hours at 2500 watts. Replacement cost is $2000+.
Who sees the problem of feeding power to the larger grid?
A large steam plant would not have problem changing a load of 25 MWe. This would require 10,000 BEV. I am assuming the solid state technology that works on my mini grid would work on a large scale. While I am familiar general electrical theoty, I am not an electrical engineer.
To put this in perspective, the 2000/2001 California rolling blackouts would require a million BEV all parked during the day at V2G inverter/charging stations.
This would have a capital cost of at least 100 billion dollars. This does not include maintenance of equipment out in the weather. That is just one silly state that did not build the needed steam power plants.
‘With improvements to the system, V2G could actually improve electric car battery life and be profitable for everyone involved.’
Great! Get back to us when you have improved the system.
All storage schemes are net consumers of energy.
and FFs aren’t?
Very interesting
Thank you
Sorry boss, can’t come to work today. Big demand on the grid.
as i wrote above,
hasn’t happened to my
brother in law in 1.5 years
of owning an ev bmw.
i think you’re just making that up
There is so much stupidity being advocated by this pair of rent seekers, rational thinking is getting swamped
Best solution long term will be cheap and safe Nuclear Power, which can be done if you don’t force everyone to build reactors that must be used for making bombs too.
Take that cheap Nuclear Power and use it to convert water into hydrogen, and use hydrogen as a portable power source. Burn the hydrogen which turns it back into water, and repeat.
THANK YOU for that. Spread tthe word with special attention to the young… for we are reaping a foul harvest of faux-eco warriors who think wind’n’solar’n’storage is tomorrow, fusion containment and utility scale the day after that. And on radiation assessment measurablle-vs-actionable, logarithmically challenged.
hoffman – sure. can we bury
the waste in your neighborhood?
or nimby?
I just paid a record sum of $2600 for a used car [2004]. Most recent was a 1993 purchased in 2008 for $900 which I got 8 good years from. Have never owned a new or even almost-new car. For some I paid less than $1500 but on average by the end of the first year there’s at least one repair that takes it up to that.
Kids today are being fed useless garbage about internal combustion machines, and the distance they have taken us for a pittance of a penny per mile in purchase and upkeep.
Let me guess. I’m expected to drop a $30k premium for a computer and Internet-infected monstrosity of insane complexity that trades gallons you can carry in a can for kilowatt-hours that cannot, and would dim my house lights and blow the wiring anyway. I see a lot of these things being expensively towed by (gas powered) trucks. If I was a billionaire I wouldn’t be tempted.
I used to think Musk’s batteries were just “pin the tail on the electric car” donkey.
Now I realize his cars are “pin the tail on the battery” donkey.
most people want nicer cars than
a 1994 whatever…..
ps – and i own a 2001 car,
purchased in 2005
This is yet another example of pushing a bad idea like dependence on expensive unreliable energy sources then trying to fix it with another expensive bad idea by the elites, who will have a backup fossil fueled generator, and demanding that the average Joe pay the consequences by suffering or go broke.
It is Friday. I woke up early this morning, and discovered that the power had gone out. It was out for about two hours. It’s been cold, and the furnace didn’t kick on because it is electric ignition, and the fans need to be able to turn. So, went out to my pilot-light wall furnace, huddling against it in the cold. And I got to thinking about electric cars. If I had an electric car, that could be hooked up to run the house for a few hours (just furnace fans and keeping the refrigerator cycling a few times), that would actually be useful. Wouldn’t want to have much else running other than the essentials of keeping food from spoiling, and keeping me from freezing. Of course, a moderate-sized UPS would also work for that, and be a lot cheaper.
exactly, re UPS.
Otherwise, I cant see how I am going to hook up electric cars to server racks in the comms room 😀
janice – most people don’t live
somewhere where the power goes
out.
maybe for a couple of hours every
couple of years. but hardly routinely.
not when i was a kid……..