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EVs Are Essential Grid-Scale Storage

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Re: EVs Are Essential Grid-Scale Storage

#161

Post by audunw »

lambdasquirrel wrote: post #83
college_physics wrote: post #60

This feels gimmicky and fragile. If distributed / decentralized storage is required (sounds like a good idea overall) it is surely better to have stationary installations, with larger batteries and connectivity optimized for that purpose, not using the EV batteries currently developed for moving these two-ton exosceletons to random places... In fact you want to have the option to significantly reduce EV usage as othe…

I came on here to comment that if you do this, it requires that the EVs be connected to the grid. How is that going to happen during the day when a lot of folks are at work, or out and about, and there aren't that many public chargers? I don't think this whole EVs-as-grid-storage really makes sense. When the EVs go into the scrap market, the batteries will likely still have 80% of their range left (if not more, based…

> I came on here to comment that if you do this, it requires that the EVs be connected to the grid. How is that going to happen during the day when a lot of folks are at work

Having chargers at the office is a thing. You could imagine grid operators subsidizing setting up EV chargers at office parking lots on the condition that they're V2G capable.

I wouldn't mind letting my EV charge at home at night and discharge down to, say 50%, at work.

Also, there's generally a big peak just as people come home from work. I could charge at night, discharge the first couple of hourse right after I come home, and then charge again.

I don't always drive to work either, I hope to take the bus or train more when kids are done with kindergarten (they can walk to school on their own). But this is Europe, I get that this is less realistic in USA.

You have some good points, but I think the next 10-20 years will be so critical for the switch to renewables that we can't afford to wait. If we can get some help from V2G until more permanent solutions are in place, why not?

Re: EVs Are Essential Grid-Scale Storage

#162

Post by AtlasBarfed »

Maxion wrote: post #13

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. On Reddit, a tesla user reports ( https://www.reddit.com/r/teslamotors/comments/v4dqkp/…

- 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

Re: EVs Are Essential Grid-Scale Storage

#163

Post by londons_explore »

antipotoad wrote: post #146
devmor wrote: post #85

Earlier quoted context omitted.

Batteries are extremely inefficient. Capacitors are much more resilient in terms of charge cycles (by orders of magnitude). If one were to build a "facility" to hold short term load, that's likely what they'd use. They just can't be used in cars because they're incredibly volatile and don't hold a charge for a long period of time.

The idea of super-capacitors in cars is positively horrifying, knowing how explosive just the small ones can be. At grid level though, is there anything that speaks against them? Edit: to answer my own question, they look pretty good [1]. Significantly lower storage density than batteries (roughly 50Wh/L versus 420Wh/L for Li-ion), but still dense enough for this to be workable at grid level. The linked presentation…

Todays grids don't have much need for energy storage on the sub-10 second timeframe. Ie. there is rarely any money to be made by taking power from the grid now and returning it in 10 seconds.

For technical reasons, thats because the 'spinning reserve' - which is momentum of every synchronous motor and generator across the nation - already adequately handles this.

Also, large generation stations are required to have a 'load line' which damps high frequency oscillations. The load line can best be described as 'whenever the grid frequency starts slowing down, generators must put more energy in automatically'. Things like wind and solar typically don't have the ability to do that.

For human reasons, it's because electricity markets tend to be minute by minute at most.

For all those reasons, I don't think you'll make any money with capacitor energy storage banks (not to be confused with capacitors for grid scale power factor correction, which can be profitable).

Re: EVs Are Essential Grid-Scale Storage

#164

Post by greenthrow »

zopa wrote: post #108
greenthrow wrote: post #62

Earlier quoted context omitted.

We are not talking about multiple 0-100% cycles daily. The places where pilot programs have been run always left the car with some amount of charge so it can be driven, and you don't normally charge NMC car batteries to 100%. Vehicle batteries have 8 year 100k mile warranties today, and those manufacturers who have spoken on this topic have said that utilizing your battery as grid storage will not violate the warrant…

Posting a question in an internet forum counts as doing research, surely? It’s much more persuasive to allow reasonable-sounding questions to arise and receive polite, well-thought-out answers, as happened here, than to have everyone chanting in unison. The latter looks like a lie even when it’s actually the truth.

Starting paragraphs of misinformation with a vague question is not a get out of jail free card. That comment was full of misinformed nonsense.

Re: EVs Are Essential Grid-Scale Storage

#165

Post by pornel »

Mrdarknezz wrote: post #105

This seems like a massive waste of energy, why not just produce the amount of energy we need?

The demand for energy is highly variable. Without storage, the production capacity has to be overbuilt to match the peak demand, and then sit underutilized for the rest of the day.

Even with just fossil fuels, it's preferable to build a smaller power plant that runs 24/7 than invest bigger money in a bigger power plant and then operate it only some of the time.

See "duck curve".

Re: EVs Are Essential Grid-Scale Storage

#166

Post by Schroedingersat »

AtlasBarfed wrote: post #153
Schroedingersat wrote: post #6

Earlier quoted context omitted.

Part of it is cars get a bunch of free tax money, but most of it is that cars were at the front of the queue and locked prices in ahead of time (before the self same orders pushed prices up) and they have actual pressure to compete. There are cheaper products, but reliability and trustworthyness is an issue. A good budget offering may decide to sell out their rep or start charging premium prices. Budget offerings are…

They had better, with 230 wh/kg LFP and 150 wh/kg lithium-free sodium ion coming to mass production, and those chemistries are far safer than nickel/cobalt chemistries because they don't catch on fire, the "OEM" cost of a large battery pack will certainly drop under 100$/kWh, if it already hasn't. With sodium ion the cost should drop to 50$/kWh. I guess what might happen in a decade or so with EVs with "obsolete" bat…

What a wild and ironic twist if we actually get some increase in transit use because leaving the car at home pays for the ticket.

Re: EVs Are Essential Grid-Scale Storage

#167

Post by tuatoru »

college_physics wrote: post #60

This feels gimmicky and fragile. If distributed / decentralized storage is required (sounds like a good idea overall) it is surely better to have stationary installations, with larger batteries and connectivity optimized for that purpose, not using the EV batteries currently developed for moving these two-ton exosceletons to random places... In fact you want to have the option to significantly reduce EV usage as othe…

Battery swapping allows you to have both EVs and the benefits of decentralized stationary installations.

The "gas station" model of battery swapping has a number of features: lower sticker price on cars, key for mass-market adoption; expert battery pack charge and diagnosis, maintenance and repair; extension of pack lifetimes by offering cheaper rates to drivers who only want to go short distances and therefore can use old battery packs with only 65% of original capacity; easier power planning and control for distribution grid operators with smoothed electricty consumption and abillity to return energy to the grid in peak demand/low supply hours; easy revenue collection for local governments.

Re: EVs Are Essential Grid-Scale Storage

#168

Post by Gordonjcp »

greenthrow wrote: post #62
Yizahi wrote: post #10

Aren't people wary about using their very expensive car batteries for the grid? E.g. imagine you plug in your phone for the night, but instead of a single top up change it is now constantly discharging and charging again. Lifetime of pocket sized batteries is not too great even now, and in such scenario they will go bust 2-3 times faster, in year instead of 3 or so. Also discharge swings would be probably much bigger…

We are not talking about multiple 0-100% cycles daily. The places where pilot programs have been run always left the car with some amount of charge so it can be driven, and you don't normally charge NMC car batteries to 100%. Vehicle batteries have 8 year 100k mile warranties today, and those manufacturers who have spoken on this topic have said that utilizing your battery as grid storage will not violate the warrant…

How far down do they discharge the battery, then? Like, how much range would you expect to have at the deepest part of the discharge cycle?

Re: EVs Are Essential Grid-Scale Storage

#169

Post by dr-detroit »

brianwawok wrote: post #160
smileysteve wrote: post #98

Earlier quoted context omitted.

For some really complex lithium battery theory, if you have no long trips planned, the battery will have less wear sitting at 80% than it will sitting at 100%.

Tesla UI in fact warns you if you set the charge level to more than 90% for more than 1 day in a row. 90% is the value they suggest. I have so far "babied" my battery and max charge at 70% outside of road trips. So far, my degradation is right on track as average, which I assume is people doing the 90% charge trick - so trying to outsmart the battery hasn't worked for me yet.

[dead]

Re: EVs Are Essential Grid-Scale Storage

#170

Post by audunw »

Maxion wrote: post #13

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. On Reddit, a tesla user reports ( https://www.reddit.com/r/teslamotors/comments/v4dqkp/…

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).

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