Re: Grand Apagon - Electricity (not) in Spain

On 4/05/2025 4:30 am, john larkin wrote:

On Sat, 3 May 2025 19:23:11 +0200, Jeroen Belleman
<jeroen@nospam.please> wrote:
 

On 5/3/25 17:12, john larkin wrote:

On Sat, 3 May 2025 14:24:07 +0200, "Carlos E.R."
<robin_listas@es.invalid> wrote:
>

On 2025-05-02 12:03, Martin Brown wrote:

On 01/05/2025 18:41, Bill Sloman wrote:

On 2/05/2025 2:21 am, Liz Tuddenham wrote:

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

On 30/04/2025 7:59 pm, Liz Tuddenham wrote:

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

... pumped hydro storage has the spinning
turbines, but grid scale batteries have invereters, which can
reacta lot
faster than any spinning turbine,

>
I thought the stabilising effect of a spinning turbine was because it
*didn't* react quickly.
>
The grid frequency begins to fall so energy from the moving parts is
converted to electrical power which is fed into the grid to increase.
the frequency.  This results in a loss of stored mechanical energy
which
causes the turbine to begin slowing down - which is detected by the
control system and used to feed more water/gas/steam into the
turbine so
its speed is returned to normal.
>
The interface between the stored mechanical energy and the electrical
energy demand has an almost instant response and is inherently stable
without needing elaborate control algorithms.

>
But it isn't actually doing anything.

>
Yes it is, basic electrical engineering theory.
>
In effect it is a constant speed generator connected to variable load;
increase the load and more electrical energy immediately flows into the
load, taking mechanical energy from the inertia of the moving parts.
They then begin to slow down and the much more heavily damped mechanical
regulator feeds in more energy to them from the primary source.

>
So it is completely passive. A big battery isn't a primary source but
it can provide enough DC current to let your grid scale inverter
generate exactly the AC output that you need.

>
There is a surprising amount of kinetic energy that can be stored in a
flywheel or other rotating piece of big heavy machinery. The grid has
adopted large scale solar PV and wind farms with some very flaky
inverter technology whose interractions are not at all well understood.
>
One of the internal reports I was reading recently mentioned that they
were thinking about funding a PhD to look into some of the complexities.
It is pretty clear that the system is not well thought out.
>

Why futz around with the rotating metal? It may entertain tourists,
but that's really all that it is good for.

>
Because it was always just there and now that it isn't the replacement
inverters on many of the big installations are nowhere near good enough
at simulating the required behaviour. They are too inclined to drop off
and save themselves (much like nuclear plant also does). I suspect that
Spain doesn't have a great deal of battery storage or pumped water.

>
Network grade batteries, none, I believe. There are plans for water
pump/generators. Some of the islands do have them.
>
It seems that solar panels and wind farms mostly have the type of
inverter that follow the shape of the voltage already in the grid, with
detection to bail out if things go nuts. There is the suspicion that
this was at least part of the problem.
>
But there is another type of inverters that force the shape, ie,
simulate inertia.

>
Where do they get the energy from?
>

>
To have a bit of margin to regulate, PV installations will have
to either run somewhat below the bleeding edge, or to store a bit
of energy in local batteries.
>
Jeroen Belleman

 Most run at the MPPT point, so have no reserve to save the grid.

They don't have to run at that point all the time, and can be designed to move away from it when necessary. The grid system can broadcast an instruction to do that, and the mobile phone system can instruct specific PV installations in specific localities to do that.

And a lot of cloud cover or still wind will precipitate the very crisis that needs reserve.

The system is designed to cope with that. The problem happens when the local fluctuations happen to combine in a way that the regular system can't cope with.

It doesn't make sense to me for a multi-country grid to depend on "a
bit of energy stored" in household batteries and inverters for
emergency reserve power.

When 30% of roof-tops solar panels - as they are in Australia - and an increasing proportion these systems are backed up by Tesla Powerwalls and the like - it can be quite a bit of energy.
Back in 2008
https://en.wikipedia.org/wiki/Hot,_Flat,_and_Crowded
pointed out that electric car batteries in parked and notionally charging electric cars could serve as a very effective gird-scale battery.

As the grids get greener, expect power to get less reliable and much
more expensive. Hopefully the USA will use more NG, build more
pipelines, and drill, baby, drill.

And the people who paid for the climate change denial propaganda you are parroting will keep on making a lot of money out of wrecking the climate.
--
Bill Sloman, Sydney