… but then the cooler change arrived in NSW, on Friday afternoon 19th December 2025
At 14:55 we note the temperature’s dropped markedly in and around Sydney, and the demand growth has abated as well…
Articles by Paul McArdle
Paul was one of the founders of Global-Roam in February 2000. He is currently the CEO of the company and the principal author of WattClarity. Writing for WattClarity has become a natural extension of his work in understanding the electricity market, enabling him to lead the team in developing better software for clients.
Before co-founding the company, Paul worked as a Mechanical Engineer for the Queensland Electricity Commission in the early 1990s. He also gained international experience in Japan, the United States, Canada, the UK, and Argentina as part of his ES Cornwall Memorial Scholarship.
NSW ‘Market Demand’ past 12,000MW … how high will it go (on Friday 19th December 2025)?
At 13:45 (NEM time) on Friday 19th December 2025 we see the NSW demand climbing higher and more quickly than forecasts ... how high will it go?
Was cloud cover the driver of the steep increase in ‘Market Demand’ at lunchtime in NSW on Friday 19th December 2025?
Wondering if unforeseen cloud cover might have been a trigger for the steep rise in 'Market Demand' at lunchtime Friday 19th December 2025.
Lunchtime volatility in NSW on Friday 19th December 2025
A quick snapshot from NEMwatch at 12:30 (NEM time) on Friday 19th December 2025, to mark an earlier-than-forecast arrival of prices above $1,000/MWh.
Spot price elevated already Friday morning 19th December 2025 in a very hot NSW
A quick note with a snapshot from NEMwatch at 10:55 (NEM time) on Friday 19th December 2025 to record some elevated prices that we’ve seen already this morning.
Violation of the ‘N>MPWW_94T_71’ constraint equation, on Friday 19th December 2025
A short note to highlight the ‘N>MPWW_94T_71’ constraint equation, which is violating in the 09:55 dispatch interval (NEM time) on Friday 19th December 2025.
Bayswater unit 2 returning to service, albeit later than expected, on Friday 19th December 2025
Bayswater unit 2 is in the process of returning to service on Friday morning 19th December 2025.
Looking ahead to Friday afternoon/evening 19th December 2025 in NSW
At 07:55 NEM time on Friday 19th December 2025 we take a look towards this afternoon/evening.
That’s a wrap, on Thursday evening 18th December 2025
Wrapping up a series of articles on Thursday 18th December 2025 with this NEMwatch snapshot at 19:35 (NEM time).
The violation of the ‘N>NIL_998_18’ constraint equation
Documenting the violation of the ‘N>NIL_998_18’ constraint equation on Thursday 18th December 2025.
About the delay in expected return to service of Vales Point 5
This morning we noted the delay in return to service for Vales Point unit 5 - here, we take a look.
Evening volatility underway in NSW on Thursday 18th December 2025
Thursday evening 18th December 2025 is upon us now, and the volatility in NSW has commenced – as we see in this NEMwatch snapshot at 18:20 (NEM time).
‘Actual LOR1’ in NSW from 15:43 on Thursday 18th December 2025
At 15:43 (NEM time) on Thursday 18th December 2025, the AEMO issued MN131786 noting 'Actual LOR1' in NSW.
Forecast violation for 3 x System Normal constraint equations on Thursday evening 18th December 2025
Another short note as Thursday afternoon 18th December 2025 advances, to flag the forecast violation of 3 different constraint equations in NSW this evening.
The ‘#NSW1_E_20251218’ constraint equation, on Thursday 18th December 2025
A quick note, about the ‘#NSW1_E_20251218’ constraint equation (which is invoked in the ‘#NSW1_E_20251218’ constraint set) – at the 13:00 dispatch interval (NEM time) early Thursday afternoon 18th December 2025.
‘Sometimes diversity does not help’ … such as on Friday 31st October 2025
On Wednesday 3rd December, the AEMO held its annual Intermittent Generation Forum and discussed a number of different aspects of challenges and opportunities, including with respect to the frequency weakness on Friday 31st October...
The ‘forecast LOR3’ that persisted through the night slips back to ‘forecast LOR2’ … but might rise again
Someone’s just asked me, so for the benefit of readers I’ve shared below a zoomed-in version of that last ez2view window (now at 08:50 NEM time Thursday 18th December 2025) for an updated view.
How much Semi-Scheduled VRE expected to be available on Thursday evening 18th December 2025?
Other factors in the forecast LOR3 we're currently seeing for NSW on Thursday evening 18th December 2025 is what's forecast to happen to Semi-Scheduled VRE output.
How many coal units in NSW expected to be available on Thursday evening 18th December 2025?
One factor in the forecast LOR3 we're currently seeing for NSW on Thursday evening 18th December 2025 is that 4 of 12 coal units in NSW are offline (and another has a story).
Forecast tight supply-demand balance this evening upgraded to forecast LOR3 (i.e. load shedding) in NSW, Thursday 18th December 2025
At the 05:50 dispatch interval NEM time on Thursday 18th December 2025, the AEMO is forecasting LOR3 (i.e. load shedding) for NSW this evening.