Re: The Physics Behind the Spanish Blackout

On 11/06/2025 13:03, Bill Sloman wrote:

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:

...

>
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.
>

>
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.

>
That would be less silly, but still silly.
>

>
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.

>
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.

>
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.
 

Why would the "fossil carbon extraction industry" even care about this book?  You seem to be imagining some shadowing conspiracy group that is directing a war on electricity and the earth's climate.  That's nonsense - there's just a bunch of companies trying to make a profit from their businesses and investments, and down-playing the risks in order to make a short-term profit.  It's just normal capitalism, and like any other branch of industry, it is a problem when they are too powerful.  But it doesn't help to be paranoid and imagine a conspiracy that does not exist.
Companies that make their living from fossil fuels do not care about some little book written by a journalist.  Why should they?  The people who read a book like that have no influence of significance.  The people that invest in their companies, or buy their products, wouldn't bother with such a book.

 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
 

You underestimate it.

It would make their charge state unpredictable

 Within negotiable limits.

Sure - but it would still be unpredictable.  One of the big hurdles for electric cars is fear of running out of juice, because it can be difficult to find working chargers in many places, it can take a long and somewhat unpredictable time to charge (especially if you need to wait in a queue), because the car's estimates of remaining charge can be so inaccurate, and because sometimes you unexpectedly need to drive more than usual.  A lot of electric car drivers start worrying at 50% charge - they will not be happy about starting the day lower than that.

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

Sure, paying for it helps.  But rather than buying a car with a huge battery and renting out half of the capacity, it makes a lot more economic sense to buy a smaller and cheaper car.

 

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.
 

Lots of people don't have a home garage and a big enough power connection.  And those that do, will want to use it for charging - not discharging.

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.

I never suggested anyone would do this for free.
It is a silly idea, no matter who is paying for it.  It is a silly idea for electricity companies to pay for the expense of lithium batteries compared to cheaper battery types, for the extra expense for the packaging that is needed for car batteries but not for fixed installations, for the much higher costs associated with replacing worn batteries, and paying the car owner enough to compensate for their not insignificant inconvenience in the whole thing.
It makes much more economic sense to use fixed installations with cheaper batteries.  Who pays for the capital costs, and the running of the system will depend on who benefits most - the owner has on-hand bulk energy for charging their car faster without high peak current costs, and the electricity company has lower costs by better balancing of overall production and local distribution.  It means the money is being paid for something /useful/ - rather than for compensation for an artificially created problem.

 

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
 

There is an overlap, but many, many differences - in the electronics, the control, the batteries, the housing, the connections, the regulations, the economics.

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.

So saying "electric car owning households are tending to have both" is nonsense.

 

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.
>
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.
 

Why would anyone recommend an expensive, inconvenient and environmentally damaging technology over a cheaper, easier and cleaner alternative?  Your arguments make no sense, unless you own Tesla stock.