The takeaway (if I'm reading the graphs correctly) is that the Gladstone coal unit took over 3 minutes to respond to the Loy Yang failure. It was contracted to respond within 6 seconds, but couldn't. Fortunately the Tesla battery was able to respond within milliseconds and cover the gap. It's a good bit of PR for Tesla, and could have some negative implications for coal or gas fired backup units.

Where did you get the three minute response time number for Gladstone? It is not backed up by the article, it only mentions that it should respond within six seconds, but that "Data from AEMO (and gathered above by Dylan McConnell from the Climate and Energy College) shows that the Tesla big battery responded four seconds ahead of the generator contracted at that time to provide FCAS (frequency control and ancillary services), the Gladstone coal generator in Queensland.". I would love to see more information on the actual impact that this had.

edit: Updated with the response time from the article

The article is a bit sparse, but take a look at the output of the Loy Yang 3 and the Tesla (HPR) in this graph: http://reneweconomy.com.au/wp-content/uploads/2017/12/HPR-fr...

Tesla ramps up as the LYA3 is dropping at 1:59am, then the Tesla drops off a bit before 2:02 am as the Gladstone generator kicks in (not in the graph)

There are two types of people in the world: those that can extrapolate meaning from an incomplete set.

While we're extrapolating meaning, I noticed that the first graph shows the HPR kicked in a few seconds before the frequency stopped dropping. Does that mean that the HPR did little to nothing to arrest the fall in frequency, and that it was the Gladstone generator, which the article says activated four seconds after the HPR, which deserves the credit?

4 seconds faster (within milliseconds of the frequency drop event occurring) than the coal plant contracted to provide frequency response services.

"But in reality, the response from the Tesla big battery was even quicker than that – in milliseconds – but too fast for the AEMO data to record.

Importantly, by the time that the contracted Gladstone coal unit had gotten out of bed and put its socks on so it can inject more into the grid – it is paid to respond in six seconds – the fall in frequency had already been arrested and was being reversed."

TL;DR The reserve system did this to show its skills. It can respond faster than any existing base load generators, and can derive revenue not only from providing energy on demand, but also grid services (in this case, frequency response).

Tesla plans to provide these services in a virtual fashion with vehicles in the future: https://i.imgur.com/oLBNeW4.png

When a contingency happens (loss of equipment such as a generator), units respond pretty much immediately due to governor response in the unit itself (good ole' inertia). Most RTO/ISOs in the USA (I know AEMO is in Australia) have a very large amount of power already ready to go if a unit trips offline. Using batteries to help with this is being worked on. They already exist, but new market rules are being drafted in order to allow them to be taken advantage of and properly compensated. The term is stored energy resource. Google that term in conjunction with ISO-NE, PJM, MISO, SPP, NYISO, CAISO...etc.

Market settings in the Australian NEM mean that generators tend to set their governors with very wide deadbands.

http://www.escosa.sa.gov.au/ArticleDocuments/1047/20170208-I...

Interesting...sounds bad for reliability. Do you know why that is allowed?

The requirements were relaxed because the intention was to have an entirely market-driven mechanism for frequency control. The system reliability impacts were an unintended consequence.

That's because it didn't need to provide more to make up for the slump in frequency, that was the whole purpose of the exercise.

The Honesdale Power Reserve can deliver up to 100 MW; 70 MW of those for 10 minutes and 30 MW up to 3 hours and it was built in less than 100 days.

https://en.wikipedia.org/wiki/Hornsdale_Wind_Farm#Hornsdale_...