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EVs Are Essential Grid-Scale Storage

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Re: EVs Are Essential Grid-Scale Storage

#151

Post by foobazgt »

shagie wrote: post #76
trashtester wrote: post #46

Earlier quoted context omitted.

> Buuuut... Delaying charging till later is free. This functionality is already there. > So each kwh cycled into and out of the battery costs 8 cents. This is quite much. If you add other infra overhead, feeding power back into the grid is not going to produce much revenue for the individual unless the selling price is maybe 20 cents above the price when charging. On the other hand, something that MAY make more sense…

> And even for grids where blackouts are infrequent, if your car can serve as large UPS for your house (combined with a large capacitor to keep the power stable), such functionality in the charger may be worth the cost of the hardware for many people. (Bringing the number of units up and hence the cost per unit down over time.) https://www.tesla.com/sites/default/files/downloads/tesla-ne... > Warranty Limitations > T…

V2X (vehicle to grid, home, or load) is pretty new, but there are some vehicles out there with it. Tesla is not one of them. They seem to be more focused on solving storage with powerwall. I don't know where that's good or bad, but I do wish I could use my Tesla to jump another dead EV.

Re: EVs Are Essential Grid-Scale Storage

#152

Post by danans »

devmor wrote: post #85
danuker wrote: post #44

Earlier quoted context omitted.

It worries me that if industrial-purpose batteries cost the same and have similar degradation, grid services will also decide not to charge/discharge if the profit is less than 8 cents. This tells me that Li-Ion batteries are far from the ideal medium for grid storage.

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.

> 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

The problem is that capacitors (assuming you mean super and ultra capacitors) don't have much capacity compared to batteries, so their cost per MWH of storage is high even if their cost per MW is low.

Re: EVs Are Essential Grid-Scale Storage

#153

Post by AtlasBarfed »

Schroedingersat wrote: post #6
raxxorraxor wrote: post #2

I don't understand the discrepancy between EV kWh and house battery kWh. Some cars have > 100 kWh capacity. Why do I pay > 1000$ per kWh for a house battery? At some point it is cheaper to just buy a car, even if you would never drive it. A Tesla Powerwall has 13 or so kWh? Why don't they use the car battery with nearly 10 times as much capacity? It is just unit prices that are far better for cars? Is the charge/disc…

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" batteries in the used market is that you just get a used EV and you have a powerwall and a secondary/tertiary city car.

Re: EVs Are Essential Grid-Scale Storage

#154

Post by audunw »

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…

> Aren't people wary about using their very expensive car batteries for the grid?

As an EV owner, no.

We need to own a car due to having kids, we happen to have gotten one with a pretty large battery so we can easily use it for road trips too. Also because there was only one choice for battery size with the model that suited us (Ioniq 5)

But I live close to work. I fully cycle the battery maybe 2-4 times a month. I could easly double that and still not wear out the battery in the lifetime of the car. If not more.

This is in Norway, so I get that others wouldn't buy an EV with a large battery in that situation. But as EVs/batteries become cheaper in general, this will be the norm elsewhere.

And then you can flip the question on its head: if you expect to only use half of the life cycles of the battery within the lifetime of the car itself, isn't it incredibly stupid and waste of valuable batteries to NOT use it for V2G?

I suspect the cost equation will be benifical for car rental companies too, since they can get economies of scale when replacing the batteries.

> so if its lifetime will be shortened from I don't know, say 10 years, to 3 years

Uh, 3 years? Even my previous EV, a 2015 Kia Soul EV, with a pretty bad battery chemistry, only air cooling, and high cycling rate since the battery was small, is still in very good condition after 7 years. Even Leaf batteries without cooling have lasted 10 years.

First gen Nissan Leafs and Kia Souls are borderline unusable once their battery degrades to 75%, but new EVs with large batteries should still have useful range with 75% degradation, so using up the rated battery cycles (generally specified at the point where degradation reaches 80%) doesn't mean the car is dead.

Re: EVs Are Essential Grid-Scale Storage

#155

Post by tuatoru »

danuker wrote: post #44
londons_explore wrote: post #25

Earlier quoted context omitted.

Luckily, any degradation can all be predicted ahead of time. A 60kwh car battery might cost $10k, and allow 2000 charge cycles. So each kwh cycled into and out of the battery costs 8 cents. So a smart algorithm can decide it's worth draining the battery back into the grid if the profit to be made is more than 8 cents. Buuuut ... Delaying charging till later is free. So another car owner's car might see on the futures…

It worries me that if industrial-purpose batteries cost the same and have similar degradation, grid services will also decide not to charge/discharge if the profit is less than 8 cents. This tells me that Li-Ion batteries are far from the ideal medium for grid storage.

There are various niches in grid storage.

Li-ion are good for frequency stabilisation: initial response times of the order of ten milliseconds, run times up to several tens of minutes maybe.

For longer durations, flow batteries and other chemistries are probably better. They win because of very good cycle life and calendar life (20_000 cycles, 50 years) but tend to take longer to start up.

Flow batteries include vanadium redox, zinc-bromine, iron-saltwater (being piloted). Other chemistries: sodium-sulfur (NaS, developed by NGK and sold by BASF in Europe/NA), carbon polymer based (PolyJoule), and a great number of experimental types.

There are also thermal batteries and compressed air energy storage, and pumped hydro.

Pumped hydro is by far the biggest form of grid storage today and is not as limited by geography or cost as one might think. It can be used in the "hours to months" range of energy delivery durations.

Re: EVs Are Essential Grid-Scale Storage

#156

Post by sonarone »

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…

In California, recently approved NEM3 makes people involved in the energt market - paying or earning rounded rate for that specific hour. Few hours during summer months can earn you $1-2 per kW, so single discharge of EV at that time would earn you $100-200, easily outweighing the cost of degradation.

New rule has been strongly criticized about being more costly and disentivizing solar, but the one thing it does right, is insentivizing end users to do a propertine shifting of their usage.

Re: EVs Are Essential Grid-Scale Storage

#157

Post by brianwawok »

audunw wrote: post #154
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…

> Aren't people wary about using their very expensive car batteries for the grid? As an EV owner, no. We need to own a car due to having kids, we happen to have gotten one with a pretty large battery so we can easily use it for road trips too. Also because there was only one choice for battery size with the model that suited us (Ioniq 5) But I live close to work. I fully cycle the battery maybe 2-4 times a month. I c…

Do the newer batteries even degrade past 50%? The first 10% happens pretty fast, but then the curve seriously flattens. I am not sure I could get to 75% degradation before the battery just gives up and dies of old age.

Re: EVs Are Essential Grid-Scale Storage

#158

Post by brianwawok »

nickelcitymario wrote: post #77
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…

The way I read it, the paper is more interested in what happens to EV batteries when they drop to 80% of the maximum storage capacity. If I understood them, they're saying that at this level, the battery is no longer suitable for transportation purposes. So what do you do with the old battery when you replace it? They're suggesting using these extremely expensive but no-long brand-new batteries for additional grid st…

Modern fluid cooled batteries (Basically anyone but Nissan I believe?), the battery should last the life of the car. You would only really have a spare if

1) The battery gets damaged or the car is totaled (in which case, you might not want it)

2) The car is 20 years old and done with life

Re: EVs Are Essential Grid-Scale Storage

#159

Post by 1234letshaveatw »

manholio wrote: post #29
rbanffy wrote: post #24

Earlier quoted context omitted.

> Energy is fungible: one cannot compete on "quality" of energy, just on price It is fungible, but prices can vary according to limitations on supply. If the big company's capacity is maxed out and demand continues to increase, energy already acquired at lower cost and stored in the car can be sold for profit.

But if that limitation is repetitive to the point of investing in infrastructure to use EVs, then some other large-scale investor will close that arbitrage opportunity. Basically, the next-day / week energy markets, where EV owners can compete, will be saturated by grid-scale battery operators. Renewables will leave large gaps for seasonal energy needs - for example two weeks of winter with no sun and no wind - but E…

I see, renewables will only leave gaps that fit your argument. You don't see any scenario where there could be brownouts during the day, say in the summer when AC usage is high?

And no, using cars for grid-scale storage has not been tried multiple times. The technology has never been available/feasible at a large scale before.

Re: EVs Are Essential Grid-Scale Storage

#160

Post by brianwawok »

smileysteve wrote: post #98
bluGill wrote: post #68

Earlier quoted context omitted.

You are missing something: lifetime depends on how much you cycle the battery. If you take the battery from 80% to 50% 5 times feeding the grid you do a lot less damage to the lifetime than just one 100% to 0% cycle, even though the first supplied more power overall to the grid. Smart management of batteries can ensure that this happens.

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.

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