Meanwhile in the real world, here is the result when the green revolution doesn't go as imagined, due to failures in planning and mismanagement. Case study Germany:
https://www.euractiv.com/section/energy-environment/news/gro...
Why can't you charge that with a 1kWh draw over 10 hours you park the car overnight?
If everyone has an electric car and that car is always plugged in when not in use, regardless of where you are, then car batteries are only out of grid use while they're being driven.
The electrical grid must be such a difficult thing to manage, even with cars acting as local grid storage we'd need supplemental neighbourhood/regional storage units as well as a way to handle any unexpected peaks.
I mean I know there's the whole "Coronation Street finishes and everyone turns their kettles on" thing but imagine if at x time on x day everyone collectively did turn their kettles on - literally everyone, every single household. It would blow the grid no matter what the operators tried to do.
In a way we need grid storage in the form of batteries to enable better use of green/local energy sources, but I think it would be smart to include some sort of chemical based generation capacity with that local storage, some way for us to store energy in a solid form say, then never use it apart from very unexpected peaks where the system needs to scrabble to find more juice.
Unfortunately a lot of potential fuels are also flammable, not really the best thing to have a huge stockpile of in your neighbourhood. Maybe a huge flow battery fed by massive underground tanks, if we ever manage to improve that technology...
Average wind production over the last 2 years in the UK is 5.8GW, with the peak (>6GW) between 1400 and 2200, and trough (<5.7GW) between 0200 and 0800, a total of 140GWh a day
But that's only a 5% variation between high and low.
Total demand though is lower at night than in the day. It's 25% down on the low at 0300-0400 and 17% up on average from 1800-1900, which more than offsets the daily variation in wind.
Throw in grid solar and sure, more renewables during the day (domestic solar isn't measured aside from a drop in demand) and you get an average 24% of current UK electricity driven by renewables, with a peak of 33% at midday and trough of 18% from 1900-2100.
But if you doubled wind that average peak would be 52% at 1200 for renewables, and a trough of 36%.
Assuming an infinite capacity grid (as the data isn't readily available), doubling wind+solar energy would save 40TWh of gas a year even with current demand. Tripling would save 60TWh, increasing 5-fold would save 76TWh, reducing Gas usage from 88TWh a year to 11TWh a year.
Those savings are based on real world generation and demand data from 2021.
Sure wind and solar can't entirely replace gas on its own, but it can knock usage down by 90% quite easily by putting up more strings between areas of the grid and simply building more.
You don't need to eliminate fossil fuels completely to make a difference.
That said, smoothing out the daily cycle would help a lot too, even in cold winter days. But Germany and friends have decided to phase out nuclear before alternatives are actually deployed, which has led to like the worst winter… so far.
The company I work for in the main strategy is to facilitate AC charging points in places you are naturally stopped for enough time to top up charge. So home, work, shopping areas being the most obvious.
So small frequent incremental opportunities to top up or in the case of this article contribute to the grid.
There are definitely lots of solvable problems in this space that underpinned by the correct financial models will contribute a lot positively to climate change.
Topping up from solar during the day and from wind during the night along with predictive (per driver) charging models will go a long way. Whilst complex the challenges feel very much in the realms of scheduling and loading cargo onto ships Vs autonomous driving from a software side. For hardware (chargers) it's really down to plentiful supply in the main.
Not if you schedule your EV to top up the battery at night.
1. After the evening commute in the early hours of the night, people are still awake at home using energy.
2. Homes are less efficient than offices + schools for many reasons (human density is generally more power efficient than everyone being spread out and not sharing resources), so demand goes up.
3. And that demand goes up precisely as supply — due to sunset — goes down.
In that light, EVs are actually great for energy storage, assuming you get appropriate compensation from the utility companies for the cost of battery degradation — which also could be in the form of "demand pricing" where it's cheaper if you don't draw power from the grid at certain times. They are available for use right when there's a supply problem: early in the night. And then you could schedule them to recharge when demand drops late at night and the grid has excess power... Or, as more charging infrastructure gets built, you could also charge while at work and the sun is up.
In some places there might be parts of the year where you still face a supply issue with solar: if the sun regularly sets before 5pm for part of the year, you'll still face some supply issues (although at least only when people are crowded in offices and schools, so demand is lower).
California has hourly graphing of electricity demand vs supply, which is quite useful: https://www.caiso.com/TodaysOutlook/Pages/default.aspx You'll notice that while demand begins to climb at around 4pm, it's still fairly low at 5pm, and really only peaks at 7:30-8pm. By midnight demand has bottomed out again, which is a great time to have your car schedule charging time, leaving you with plenty of juice for the morning commute — a standard US dryer outlet will charge a Model 3 at about 30 miles per hour; assuming you leave at 8am that's 240 miles of range, so even if you ran it to zero — and probably you should not do that and only run it to 20%! — just about anyone would be be to make it into their workplace, since the average American round-trip commute distance is less than 50 miles.
Frankly it would take a hell of a lot to convince people to be ok with getting home, plugging their car in, and having the charge level go down instead of up. I certainly wouldn't be comfortable with it.
I might sign up for this if my household kept at least one ICE vehicle, but not otherwise.
Paying people the right price for their V2G supply will go a long way to making them comfortable, I think. The ones that aren’t don’t have to.
I admittedly live on the eastern edge of my time zone (Boston), but my evening commute is fully past any meaningful solar production for almost half the year (solar is producing under 25% for ~14 hours per day on a year-round basis, more in winter).
As we continue to electrify space heating, more electricity will be demanded on winter overnights (when you lose solar PV but also have increased building net heat loss).
To me, this points towards “use nuclear for base load, dummies…”
I'm not too obsessed but it was easy enough to look up the data on what charge states result in the least loss of range over time.
This happens precisely because of supply-demand - peak dispatchable bulk generation is more expensive. VtG brings a lot of cheap supply bringing prices down and causes balancing stress on distribution grid, increasing distribution costs. 5x sounds like an absolute pipe dream
We’re approaching this with the recent LFP generations.
People are afraid of actually using their batteries, and engaging in FUD about their aging. It's weird.
And some of the same people change cars a year later (talking about EVs, of course — because it doesn't have HW4, 4680s, etc.). Some of it is human nature, though.
A typical car battery is rated for thousands of cycles. 3000 cycles is a number you hear often. If you have an EV that has a range of 300 miles, we're talking about 900000 miles. That's more miles than the vast majority of cars will drive over their lifespan. The average driver drives less than 15000 miles per year. The car will die before the battery typically, not the other way around. And the battery isn't completely dead at that point, it should still be good for 80% of its original charge. The vast majority of EVs ever produced are still driving with their original batteries and will be for years to come.
A second point is that EV batteries are designed to discharge in a few hours to drive the car. There is no way you'd discharge at that speed via v2g. Most home connections charge/discharge only at a few kw. It's a comparatively light load for the battery and the wear and tear is pretty modest. Battery degradation happens a lot faster if you stress the battery. There are some indications that suggest that v2g discharging has only a very minimal impact on battery life. You wouldn't fully discharge the battery. Not even close.
A third point is that with smart chargers, you would be able to control when the battery is allowed to discharge and how much. A million cars contributing just a single kwh each is 1 gwh. That's a huge amount of power. You would not fully cycle the battery typically but maybe only a few percent. If you start with 3000 cycles and you use 10% of that every day (which would be a lot), you could do that for 30000 days.
Finally, instead of providing power to the grid, you could use a system like this to power your house and make save significant amounts of money in the evening by using your car instead of expensive grid rates using power that you got from your solar panels during the day for free.
Those savings can really add up over the years. If it worries you, you can invest in a house battery instead. In the end the argument has to be financial and v2g is probably cheaper overall than that. People are spending tens of thousands of dollars to put solar on their roofs. So, throwing their car battery in the mix is a comparatively small step and a perfectly rational thing to consider. But the numbers have to make sense for people to opt in to that.
That is a ridiculous assertion and negates everything you said past this point. A lithium ion battery without a BMS is easily akin to an incendiary device and would never be in a car.
I think you misunderstand what a battery management system is. If a Li-Ion battery had no BMS -- especially one that is large, high power, and composed of many cells, it would literally be an incendiary bomb if not carefully managed by the user. The BMS is responsible for maintaining the cells -- they must be equalized and cannot go below or above certain voltages, and the charge controller is not the unit responsible for doing this while the pack is in use.
By claiming that there were no battery management systems in earlier EVs you are showing ignorance about the workings of these systems to the point where it is difficult to trust the other things you say. What is your background for this knowledge? Can you provide references to your claims?
I think you are just playing semantics here. Obviously they had some simplistic controls on the electronics. But no smart distribution of load, cooling systems, etc.
Calling people ignorant is not nice BTW. Says more about you than me. Insisting on references is also a bit weak. Where are your references? I suggest you do your homework with some Googling and then come back to apologize. Would be the nice thing to do.
Citation needed?
As far as I know even the 2012 Leafs had a per cell thermal management.
I think in the earlier Leafs a lot of the intelligence on charging operation and battery cooling/heating was offloaded to the BCM module but it is a bit of a hyperbole to say that there was no battery management.
They may not have had a dedicated BMS module in the OEM sense of BMS (like what Infineon now makes) but they certainly had temperature/charge management controls.
Nissan leaf had cell level voltage and temperature monitoring, it also had a rudimentary heating element that would not let the battery freeze solid.
Its battery also was poorly designed so some of the cells had worse conditions than others and the batteries "died" because a few cells went out of limits and the BMS would limit the performance/range of the car. The rest of the cells could go much further. Also you should never charge lithium batteries (other than LTO) below freezing as it forms crystals that are lost to the capacity. Leaf did not to my knowledge compensate for this.
Moreover 24kWh battery doing 1000 cycles is about 100 000 km of driving.
Then there is Tesla batteries that have liquid cooling and heating of the whole pack. Battery is never charged below freezing, also above freezing the charging is adapted to the cell temperatures and for fast charging the battery temp is raised up to 60C, above 65C the cooling kicks in.
The batteries are much larger in Teslas, typically say 80kWh. That combined with better efficiency, better battery management, lower power draw per cell, etc means that they get more than 1k useful cycles out of it. Say 2k (tho they claim more, and there is considerable variability due to use and environment). So 500km * 2k cycles is 1 million km.
The battery may degrade due to age before it reaches its cycles.
Also as mentioned above. Tesla does draw up to 300kW out of the battery. The onboard AC charger is 11kW so if that is bidirectional then the it is really gentle on the battery.
That said, I'm not dissing Nissan, they were truly innovative and we owe them lots of gratitude for popularizing EV's and they have also evolved their tech considerably. Others are doing battery management very well as well nowadays.
"The purpose of a BMS is to:
1. Provide battery safety and longevity, a must-have for Li-ion.
2. Reveal state-of-function in the form of state-of-charge and state-of-health (capacity)
3. Prompt caution and service. This could be high temperature, cell imbalance or calibration.
4. Indicate end-of-life when the capacity falls below the user-set target threshold.
Not all BMS offer all these features. The most basic functions are battery protection and showing state-of-charge (SoC)."
Without battery protection and while running many hundreds of individual cells your battery will catch on fire. I will bet the house on that. No EV maker would ever make an EV without a BMS.
You have gone beyond ignorance at this point by claiming that you are insulted and asking for an apology. I won't ask you for one, but I will ask for a public correction and acknowledgement that you were wrong.
I think it's all called battery management. But early EV models did not have a whole lot of it. It obviously had some electronics to read out the current charge and put some basic limits in place. But no thermal management or cooling or any of the smart battery management features you see in more recent models.
You are ignorant of battery systems. It's okay to be ignorant of things but it's not okay to spread misinformation.
I am an electrical engineer. I have worked on battery management systems with 100+ million units produced.
I can tell you that it would literally be an incendiary bomb without a BMS, and that no part of modern production battery systems are "simplistic", including the Nissan Leafs.
I feel like we should be mandating easy and near-cost replacement for EVs to make sure that this is less of a problem. Battery wear aside, EV's have the potential to greatly outlast ICE's. We should be treating batteries just like tires and brakes.
I agree that using EV batteries as grid storage isn't a particularly great idea.
Thus hard to replace.
2) The loss of value to the owner based on cycles used needs to take into account that the failure of the battery in a vehicle can be what causes its final retirement, i.e. the condition of the vehicle itself does not justify a new battery expenditure. EVs are more like cell phones than ICE cars, which can have lifespans of over 30 years in the right climate. So losing 10% of your cycles to grid support could mean buying a car at nine years instead of ten years.
Take a $40000 EV with half of the value being in the battery. Financed, say it's $600/month on a six year loan. With a ten year life span that's four years of no payments. With V2G say you lose 10% of your cycles, so you have three "free" years instead of four. Your real cost is 12 * $600 = $7200.
You can't just calculate the pure cost of the battery with V2G, you need to take into account the depreciation on the entire vehicle as it relates to the battery. In fact, we know very little about how BEVs will depreciate.