Re: The Physics Behind the Spanish Blackout

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

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

On 10/06/2025 8:08 pm, Liz Tuddenham wrote:

Bill Sloman <bill.sloman@ieee.org> wrote:
>

On 10/06/2025 10:04 am, john larkin wrote:

On Mon, 9 Jun 2025 16:37:28 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:
>

On 6/9/2025 1:44 PM, Liz Tuddenham wrote:

Carlos E.R. <robin_listas@es.invalid> wrote:
>

On 2025-06-09 21:54, Don Y wrote: > OTOH, we're sticking with other
technologies (fossil fuels -- coal -- and > nukes) despite obvious and
yet to be solved problems INHERENT in their > technology.  Adding
"inertia" synthetically to a network is a considerably > more
realistic goal than sorting out how to deal with nuclear waste or >
the consequences of burning carbon.
>
Solar and wind can be made to impose a gigantic inertia with
appropriate electronics. You can fixate the output at 50Hz, locked no
matter what.

>
Only if the surplus energy is available to supply the necessary
current.

>
But that assumes the old usage model where the utility was the "tail"
wagged by the consumer "dog".
>
Going forward, expect to see a closer integration of load and supply
management.  It's just silly to over-provision just to accommodate any
*possible* demand when technology exists to predict and manage that
demand.

>
Right. People shouldn't just be allowed to cook or do their laundry or
heat their houses whenever they feel like.

>
But they can be offered cheaper rates to do it when the grid is less
heavily loaded.
>
https://en.wikipedia.org/wiki/Hot,_Flat,_and_Crowded
>
spelled it all out back in 2008. Back then Thomas Friedman laid a lot of
emphasis on electric cars which are parked 95% of the time and
potentially available as a gigantic grid storage battery.

>
Are the batteries in those cars designed to only accommodate the 5%
normal usage?  How would they cope with the constant charging and
discharging needed to stabilise the grid?

>
I don't know what the batteries in those car are designed to accommodate, and clearly neither do you. It's going to be a lot more than 5% of the capacity.

 Usage and capacity are not the same things.  It seems reasonable to expect that most of the time, car batteries will be between 20% and 80% of their capacity, though they will get closer to 100% for people who charge overnight at home.  But 5% "normal usage" means a typical car is used no more than 5% of the time - a bit over an hour a day.  That also seems reasonable to me, and it is the figure NXP use when estimating lifetimes of automotive qualified parts.  (I.e., they give a lifetime of 10 years on the expectation that no more than 5% of that is at 125°C temperatures.)
 Not only do neither you nor I know how well car batteries, and the charging and discharging power circuitry around it, would work for grid storage, but I suspect the car manufacturers do not know either.  The use-cases are very different.
 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.
The "Tesla power walls" are essentially the same batteries, and electric car owning households are tending to have both.
--
Bill Sloman, Sydney