Unless the $/kwh or lifecycle count of EV batteries change significantly, using them as a grid-scale storage is just not financially feasible.
E.g. a NMC battery has a lifespan of around ~2000 cycles, a model S 90 D has a 90 kWh battery. That's around 180 MWh of total energy that can be moved through the battery before it is dead.
This means that the replacement cost of the battery for the owner costs ~ 106 USD per MWh hour, which is more than most generation sources (https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#...). In other words, it's cheaper to build and run a natural gas power plant than to pay EV owners for the grid-scale storage capacity from the NMC batteries in their cars.
Battery lifespan in 'cycles' is kinda simplifying things too much.
Most batteries, if charged and discharged slowly, in the right temperature range, and while keeping the charge between 40 and 60% capacity, get far higher lifetime than the advertised 'cycles' number.
The damage and degradation happens mostly near 0%, near 100%, when charging/discharging fast, and when excessively cold or hot.
Cell balancing becomes less important when you're not nearly full or empty, and balancing wastes quite a lot of energy - making the battery more efficient when used between 40-60% too.
During most of last year prices in Europe were routinely over 300, 400 even occasionally over 1000 per MWh because there was an energy shortage. At the same time the prices can easily go negative if the conditions are favorable for renewables. It's not crazy to think that you would be paid to charge your car when there is an excess and then get paid a lot when there is a shortage. I don't know who would say no to this deal.
My point is mainly that there are plenty of options available to stabilize grid prices that are way cheaper than using EV's. Europes energy crisis is temporary, over time the price fluctuations will go down.
That's actually not true. Let's say your calculation of ~100 per MWh for batteries is correct, we've seen that the wholesale prices were a multiple of that basically this whole year. Nuclear is above that price. I don't think anybody is seriously planning to use car batteries as the backbone of the grid, but as one of the last resorts yes. It makes sense for everybody.
Isn't that the big question? Whoever is confident that they have correct answer to that question should invest any coin they can get their hand on right this second.
Purely from a theoretical perspective, anything that can generate power at lower prices than the current market rate will be financially viable. With this past winters prices in Europe, it means literally anything. Even at times a diesel generator from your local hardware store would be a good idea (~.60 EUR per kWh).
But these prices won't last, in a few years we will be already back down to manageable price fluctuations.
It's pretty easy to see though that if battery based grid storage is going to be a big thing, it is not going to be EV batteries. The chemistry used in them is not optimized for life cycles (at least currently). LFP chemistry batteris that are in some Teslas has bettery cycle duration. Sodium Ion batteries will most likely be the choice for grid-scale deployment if they can be commercialized.
Of course at some point in the future if a lot of people with EVs say yes to this deal, the price range will narrow significantly, and eventually stabilize to the point where it's only just profitable given battery degradation costs. But it may take a long time to get to that stage.
- Read up on LFP. their cycle counts are far higher. and newer high density stuff is coming to market that competes with NMC chemistries from just a few years ago, and they are safer and more stable chemically, so less safety systems, so any density difference gets made up at the pack level
- replacement battery costs will probably drop a LOT in the next ten years. that quoted cost is $200/kWh, but Tesla is at $100/kWh (possibly less). That is a hell of a markup, probably reflects battery supply prioritization to new cars (Tesla gets more money if you buy a new Tesla rather than keep an old one running). So lets not treat this as some permanent condition. Sodium Ion batteries should stabilize at somewhere around $50/kWh I would guess, especially if they can get them close to 200 wh/kg, which is on the roadmap. And in 5-10 years there will be some solid state, sodium-sulfur, or lithium-sulfur battery that is even cheaper.
- Gas turbines still externalize their carbon emissions aka they don't pay for them. When will that madness change? Who knows. Another example of false economics. The only way I see gas turbines as a good thing is if it keeps the oil wells from burning off their excess methane for absolutely no benefit.
Maybe you are some astroturfer or not, but it is really frustrating talking about energy policy over the next 5-10 years and counterarguments are:
- this guy for this car got charged this price this one time anecdote that you know perfectly well is not representative of future costs and availability
- dude, lets burn more fossil fuels, it's "cheaper", which you know it really isn't
- let's talk about essentially outmoded chemistries and their problems, and ignore both current ones and ones that are scaling up production
1. A battery isn't completely dead when it reaches its cycle life. It's often defined as the point where the capacity degrades to 80% of its initial rated capaity. For an EV with a large battery, most of them will be able to continue to use the battery for a good while after that. A Model S 90D is still a very usable car for many people with even 50% range.
2. You assume that every EV owner will use many cycles. That's generally not the case. I use at most 2-3 gentle cycles (charging to 80%, never discharging below 20%) in a month on our EV. I have plenty of spare cycles in the lifetime of the car.
3. Time degrades batteries as well. For EVs with low mileage, you could be throwing away useful battery cycles by not using it for V2G.
4. Most batteries, by far, will not have to be replaced until the vehicle is over 10 years old. In 10 years, it might be far cheaper to replace EV batteries. Batteries will be cheaper and you'll have better economies of scale for replacements. You might get a better battery with longer range than when the car was new too.
I seriously doubt that V2G will cause a lot of people to have to replace their EV battery in the lifetime of the car. People who drive their cars the most will not use V2G because they won't have spare battery capacity. It might trigger one battery change, but then an EV might need a battery change at one point in its lifetime anyway.. and so it doesn't mattery unless V2G triggers the need for a third replacement. (In 10 years batteries might have longer cycle life too).
It's not cheaper to run a natural gas power plant if you want to be carbon neutral. Then you have to run it with hydrogen, which is quite expensive to make. It also gets more expensive if you only want to run the gas plant a couple of hours per month because at all other times renewable power is sufficient.
> 106 USD per MWh hour, which is more than most generation sources
Minute by minute electricity prices vary really widely. It isn't unusual for prices to spike up 10x briefly at peak times.
Most power stations have too high a capital cost to only run 2% of the time... whereas your tesla battery has no capital cost, so using it to power the grid 2% of the time when the prices are sky-high is very attractive.
So people being asked to discharge their Tesla into the grid should be paid a significant premium, right?
Since they are providing power on demand in a way that doesn't have upfront costs, that should mean that car-based power demands a cloud-like premium (10-50x over traditional servers) over traditional power plants.
They are getting a little premium today, but likely won't once this practice becomes normal.
$0.11/KwH is super doable. Keep in mind that discharging is only necessary and profitable during peak demand, when prices are much higher than that. $0.50/KwH is far from uncommon. E.g. today energy peaks at €0.28/KwH in my area. It dipped at €0.17 so it would've already broke even.
There are many estimates for the generation cost on wikipedia, at least the IPCC one does not try to estimate what the costs of the emissions would be.
And the price of the battery does obviously not include the generation costs of the energy needed to charge it, any charging/discharging losses, nor the infrastructure costs of a V2G setup.
So it's a very simplistic and incomplete comparison that gives a rosier picture of V2G MWh price than reality would.
E.g. a NMC battery has a lifespan of around ~2000 cycles, a model S 90 D has a 90 kWh battery. That's around 180 MWh of total energy that can be moved through the battery before it is dead.
On Reddit, a tesla user reports (https://www.reddit.com/r/teslamotors/comments/v4dqkp/19000_n...) it costing him 19 000 USD to replace a 90kWh battery in his model s.
This means that the replacement cost of the battery for the owner costs ~ 106 USD per MWh hour, which is more than most generation sources (https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#...). In other words, it's cheaper to build and run a natural gas power plant than to pay EV owners for the grid-scale storage capacity from the NMC batteries in their cars.