Re: The Physics Behind the Spanish Blackout

On 11/06/2025 5:05 pm, David Brown wrote:

On 10/06/2025 19:01, Bill Sloman wrote:

On 11/06/2025 1:32 am, David Brown wrote:

On 10/06/2025 15:49, Bill Sloman wrote:

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Using electric cars as grid storage is just silly, in all kinds of ways.   The trade-offs for things like power and energy densities and cost are completely different, the charge/discharge usage is totally different. And cars are frequently not plugged in at the right place when you want to charge or discharge the grid storage.
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I don't think that they would be used for the short term charging and discharging involved in providing short term frequency control for the grid - the ambition seems to be have them there to provide emergency back-up when there's a substantial disruption.

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That would be less silly, but still silly.
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If we all went over to electric cars the grid would have to provide about 30% more electric power than it does now. Granting that cars spend 95% of their, time parked, the parked cars could offer about 5 times as much power as the grid for a couple of hours.

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It would be hugely more helpful to have distributed cheap battery storage in fixed installations (in homes, at grid transformer and distribution points, and most importantly, at electric car charger stations).  All it will take is mass production of more appropriate batteries (such as the sodium ion batteries that China is pushing hard).   The potential benefits of electric car batteries as "emergency grid storage" would then be negligible.

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You can neglect them if you want to, but it's still a huge chunk of stored power, and some ingenious engineer will probably work how to use for some job that none of us has thought of yet.

 Some ingenious engineer could design a generator and mechanics to attach to petrol or diesel cars and use that for electricity supply - as an emergency backup for the grid, it would be a huge improvement over using electric car batteries as it is much more scalable.  Apart from a few jerry-rigged setups in places far from reliable electric grids, it is never done.  So what makes you think using car batteries, in cars, is a realistic idea?

https://en.wikipedia.org/wiki/Hot,_Flat,_and_Crowded
the book has been around since 2008, and fossil carbon extraction industry didn't take exception to it at the time.

 It would make the cars more expensive,

Probably not. The charger would have to be bidirectional, but that wouldn't make it significantly more expensive

It would make their charge state unpredictable

Within negotiable limits.
(and no one would accept that)
Unless paid for it.

fail to provide reliability for the grid as cars are often not connected,

They got to be connected to be recharged, and the obvious place to do that is in the home garage or the work parking lot.

and  wear out the absurdly expensive car batteries sooner.  It is a silly idea.

The amount of wear is negotiable, and it would be paid for. Expecting people to agree to do it for nothing would be a silly idea, but that's your silly idea.

The "Tesla power walls" are essentially the same batteries, and electric car owning households are tending to have both.

 No, they are a /totally/ different concept.

Converting low voltage DC from solar cells into mains voltage AC to power your house is much the same idea as converting main voltage AC to direct current to charge your car battery, and the car converts that DC into variable voltage DC to drive motors that move your car.
The intentions may be different, but the hardware is pretty much identical

And no, electric car  households very rarely have both - most electric cars are not Tesla, and  only a tiny proportion of Tesla owners have "power walls".

So what.

However, the "power walls" is basically the concept I am suggesting - except they should not be using lithium batteries.  They should be using sodium ion batteries - taking perhaps 20-30% more space and weight, which does not matter nearly as much for a fixed storage box rather than a car.  The price for the batteries would be around a quarter and the environmental cost of their production would be perhaps 5% - and that's taking into account the lower lifetime cycle count of current sodium ion batteries compared to lithium.
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It should not be so difficult for you to understand that the requirements for a battery in a car, and the desired usage of a car driver, are massively different from the requirements and usage for small local grid storage.

I can understand why you may have difficultly getting your head around the concept - you do seem to be dim and ill-informed as well as simply wrong.
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Bill Sloman, Sydney