Thread by @yestiseye

@DavidOsmond8 @simonahac @sideen_dan @flexibledragnet @xoiiku @Arachnocat14 @DCMacgreiner @stewartbrand Good question btw. There's an answer, but I should compose it properly because the off-the-cuff version will ramble on for 30 tweets… no one needs that right now.
So later tonight then when I have more time.

@DavidOsmond8 @simonahac @sideen_dan @flexibledragnet @xoiiku @Arachnocat14 @DCMacgreiner @stewartbrand First I should have at least recognised you came halfway on this, with "…partly related to the high RE penetration".
My motivation is I see too much brightsiding here, and I'd rather make people upset now instead of letting them discover the hurdles down the road themselves. 1/9

@DavidOsmond8 @simonahac @sideen_dan @flexibledragnet @xoiiku @Arachnocat14 @DCMacgreiner @stewartbrand Every option comes with pros & cons; we'd benefit long term if we just dealt with those without fear or favour.

Now for anyone out there listening in who wants a tutorial on FCAS, this is a good place to start:
wattclarity.com.au/articles/2017/… 2/9

@DavidOsmond8 @simonahac @sideen_dan @flexibledragnet @xoiiku @Arachnocat14 @DCMacgreiner @stewartbrand Note the important point about how FCAS used to be (with higher CO₂ of course) "…they were effectively provided for free".
And there's all the other tagged FCAS articles at that most excellent website (that have been steadily building over time)
wattclarity.com.au/articles/tag/f… 3/9

@DavidOsmond8 @simonahac @sideen_dan @flexibledragnet @xoiiku @Arachnocat14 @DCMacgreiner @stewartbrand Now on your question about FCAS, and it being proportionally less outside SA for instance… you kind of answered that yourself already (not trying to be cute here, just brief): when SA is islanded we see the true cost of running a high% VRE grid as far as FCAS is concerned. 4/9

@DavidOsmond8 @simonahac @sideen_dan @flexibledragnet @xoiiku @Arachnocat14 @DCMacgreiner @stewartbrand Reference: wattclarity.com.au/articles/2020/…
(there will be lots of links… so that tweets are fewer)
Logically if the entire NEM were to follow down the same path, those costs would eventually scale to the full grid. More or less. 5/9

@DavidOsmond8 @simonahac @sideen_dan @flexibledragnet @xoiiku @Arachnocat14 @DCMacgreiner @stewartbrand Also the FCAS market is technically region based (though clearly while linked together, they'd not deviate too much from each other). I was hoping for something done graphically by someone else, but the raw data feed can be found here: nemweb.com.au/#ancillary-ser… 6/9

@DavidOsmond8 @simonahac @sideen_dan @flexibledragnet @xoiiku @Arachnocat14 @DCMacgreiner @stewartbrand Also there's this rather solid looking thesis (for an undergrad degree, so hopefully that makes it more accessible to people outside the profession).
"Study of Battery Systems for Frequency Regulation in the Australian NEM"
energyexemplar.com/wp-content/upl… 7/9

@DavidOsmond8 @simonahac @sideen_dan @flexibledragnet @xoiiku @Arachnocat14 @DCMacgreiner @stewartbrand + because I wanted to bring this back to Inertia, AEMO's "Inertia Requirements Methodology"
aemo.com.au/-/media/Files/…
+
"Mapping the Freq. Response Adequacy of the Aust. NEM" sci-hub.tw/https://doi.or…
+
"Power System Security Assessment of the future NEM" energy.gov.au/sites/default/… 8/9

@DavidOsmond8 @simonahac @sideen_dan @flexibledragnet @xoiiku @Arachnocat14 @DCMacgreiner @stewartbrand There's lots of good stuff here. The common thread, as you pointed out, with more non-synchronous generation, frequency stability is negatively impacted. It's just an issue that needs to be taken into account. It isn't a deal breaker; it could however be a limiting factor. 9/9