EVs Are Essential Grid-Scale Storage • Hacker News Board

Re: EVs Are Essential Grid-Scale Storage

#11

Post by manholio » Wed, Jan 25, 2023, 1:08 PM UTC

This is never going to happen at scale. Energy is fungible: one cannot compete on "quality" of energy, just on price, a kWh is a kWh and the provider with the cheapest energy will always win in the marketplace. So this means any EV owner looking to make a profit is competing against large scale industrial storage entities that:

- have large mass and purchasing power, optimizing their battery purchasing and operational costs;

- have grid-scale storage oriented solutions tuned for maximum charging cycles and lifetime-storage

- use stationary batteries with no mass penalties, affording them the use of low density exotic chemistries (Na-ion) or non-battery storage systems.

Meanwhile, the EV owner has a mobility-optimized battery that is tuned for maximum density that still results in a cycle count comparable with the lifetime of the car. At market equilibrium, any revenue he extracts while serving the grid will reduce the useful life time of the battery and therefore depreciate his capital, and make his battery a "spare parts consumable" which is a major profit driver for most auto-manufacturers, especially a custom form factor battery for a 5 year old vehicle that is no longer sold.

Never mind that the whole operational cost, changing the meter to a bidirectional one, making sure the vehicle is connected for extended periods of time etc. is probably not going to be worth the pennies you will earn.

Grid storage is EVs is a decade old pipe dream, it will never make sense economically, it has been attempted multiple times and always failed, just let it die.

Re: EVs Are Essential Grid-Scale Storage

#12

Post by throwawaaarrgh » Wed, Jan 25, 2023, 1:08 PM UTC

> Before long, there will be more EV battery capacity than the grid can use

yes, but because nobody is deploying V2G at high density housing, and also because the grid doesn't have the capacity

Re: EVs Are Essential Grid-Scale Storage

#13

Post by Maxion » Wed, Jan 25, 2023, 1:11 PM UTC

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/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.

Re: EVs Are Essential Grid-Scale Storage

#14

Post by throwawaaarrgh » Wed, Jan 25, 2023, 1:11 PM UTC

Cthulhu_ wrote: post #9

Cool, but will the energy company pay for the wear and tear? Do you get paid extra if you promise to not use your car between hours X and Y?

an energy company paying customers extra? lolllllll. if anything they're gonna find a way to charge you for the privilege of giving them power

Re: EVs Are Essential Grid-Scale Storage

#15

Post by vardump » Wed, Jan 25, 2023, 1:12 PM UTC

Soon enough (2030+) someone's going to solve NIB batteries (mainly sodium refining, I guess) and a bit heavier, but dirt cheap sodium ion batteries are going to be everywhere.

https://en.wikipedia.org/wiki/Sodium-ion_battery

Re: EVs Are Essential Grid-Scale Storage

#16

Post by VadimPR » Wed, Jan 25, 2023, 1:13 PM UTC

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/…

Does the cost of the natural gas power plant include the green house gas costs it is emitting?

Re: EVs Are Essential Grid-Scale Storage

#17

Post by moffkalast » Wed, Jan 25, 2023, 1:14 PM UTC

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…

Well the ones with li-ion batteries ought to last at least 2000 cycles, or about 6 years with a cycle each day, but there are lots of mid tier models being made with lifepo4s now, and those last like 6000 cycles, so there is far more breathing room. They're also cheaper so you may be able to more easily break even.

Re: EVs Are Essential Grid-Scale Storage

#18

Post by ramraj07 » Wed, Jan 25, 2023, 1:17 PM UTC

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…

depends on how much the demand is. If all they have want is (collectively) a small drain (less than 1-2%) once or twice a day then why not? Especially if there are some incentives provided for the same.

Re: EVs Are Essential Grid-Scale Storage

#19

Post by tboyd47 » Wed, Jan 25, 2023, 1:18 PM UTC

So not only do the batteries lose 2.3% capacity each year, and lose up to 40% of their range in cold weather, but now the power company wants to drain your car battery at night to power other people's homes. What a comedy of errors!

Re: EVs Are Essential Grid-Scale Storage

#20

Post by manholio » Wed, Jan 25, 2023, 1:19 PM UTC

moffkalast wrote: post #17

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…

Well the ones with li-ion batteries ought to last at least 2000 cycles, or about 6 years with a cycle each day, but there are lots of mid tier models being made with lifepo4s now, and those last like 6000 cycles, so there is far more breathing room. They're also cheaper so you may be able to more easily break even.

That just means people will buy daily drivers with small batteries and charge them nightly. 15 years out of a cheap compact car with near zero operating costs sounds like a good deal, still does not make sense to waste a cycle for $1 = 20kWh fed into the grid.