Both YWPS3 and YWPS4 back online overnight
A quick follow-on early Friday morning 17th October 2025 to note that both YWPS3 and YWPS4 made it back online overnight.
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.
Differing return to service expectations for YWPS3 and YWPS4, following simultaneous trips
Following the simultaneous trips (on Thu 16th Oct 2025) of YWPS3 and YWPS4, we take a look at current return to service expectations.
Simultaneous trips at YWPS3 and YWPS4 on Thursday 16th October 2025
A short note on Thursday 16th October 2025 to record both Yallourn Units 3 &4 tripping during the 13:35 dispatch interval (NEM time) today.
AEMC communicates two items, relating to a Review of the Integrated System Plan (ISP)
Amongst the many emails that hit my inbox recently was an email from the AEMC that spoke to the ‘Package of ISP reform underway’ – and specifically these two arms.
Bruce Mountain (at NEMdev 2025) spoke to his significant concerns about the ISP
A short note to follow the NEMdev 2025 conference (Tue 7th and Wed 8th Oct 2025) and to highlight a comment made by Bruce Mountain about the ISP.
Sarah Lawley (at NEMdev 2025) spoke about what she sees as ‘circular reasoning’ in the ISP
A short note to follow the NEMdev 2025 conference (Tue 7th and Wed 8th Oct 2025) and to highlight a comment made by Sarah Lawley about the ISP.
Some suggestions for the Nelson Review panel to consider (with respect to Forecasting) following review of the Draft Report
Following my presentation at NEMdev 2025 (on 8th Oct 2025), here are some suggestions that the Nelson Review panel might consider - with respect to forecasting.
Short-notice outage at Loy Yang A4 in Victoria on Wednesday 15th October 2025
At 09:06 (NEM time) this ‘Notifications’ widget alert from ez2view flags Loy Yang A4 coming offline ... which helps explain the directions for System Strength.
AEMO notes ‘Non-credible contingency event’ at Jeeralang
No sooner had we noted that ‘AEMO changes mind, and directs Murray instead (to run as syncon) for System Strength in Victoria on Wednesday 15th October 2025’ then we receive MN129618 at 09:00 that helps...
AEMO changes mind, and directs Murray instead … but this was also short-lived?!
Less than an hour after directing Jeeralang (for System Strength in Victoria), AEMO changes its mind and directs Murray instead. Though this was also short-lived!
AEMO issues directions to units at Jeeralang Power Station, for System Strength in Victoria (Wednesday 15th October 2025)
As AEMO had telegraphed yesterday, just after 08:00 (NEM time) on Wednesday 15th October 2025, the AEMO issued Directions to various units at EnergyAustralia’s Jeeralang Power Station for System Strength in Victoria.
AEMO flags possible intervention tomorrow (Wed 15th Oct 2025) for System Strength in Victoria
Worth noting two market notices today flagging possible intervention because of System Strength issues in Victoria tomorrow (Wednesday 15th October 2025).
Small spike in Mainland Frequency, with (apparent) ~400MW trip of demand in Queensland on Tuesday morning 14th October 2025
It appears that there was some large(ish) trip in demand somewhere on the Queensland network, given the spike in frequency at ~07:28 on Tuesday 14th October 2025.
Drop in ‘Market Demand’ in QLD on Tuesday morning 14th October 2025
A short note to record a large-size drop in ‘Market Demand’ in the Queensland region on Tuesday morning 14th October 2025, as captured in this ez2view ‘Notification’ widget alert at 07:31 (NEM time).
ER03 makes its way back online, Sunday evening 12th October 2025
Given that we’ve written about that outage several times before, worth noting that Eraring Unit 3 came back online Sunday evening 12th October 2025.
An initial look at the Spot Price spike in NSW at 17:55 on Friday 10th October 2025
There was a short-lived (but interesting) price spike for ENERGY in the NSW region on Friday evening 10th October 2025. Here's a first look.
Two bouts of >2 hours of Non-Conformance at Aldoga Solar Farm on Sunday 12th October 2025
A quick initial look at two lengthy periods of Non-Conformance at Aldoga Solar Farm on Sunday 12th October, with the first period seeing large negative Dispatch Error, and a blip in system frequency.
Social media abuzz with news of recent voltage fluctuations observed (early October 2025) on Spanish Grid
It was no surprise that social media lit up with reports of voltage fluctuations having been detected more recently on the Spanish Grid, as reported by Red Eléctrica (the TSO).
Four hours of Mainland Grid Frequency, on Sunday 12th October 2025
As something we might refer back to later, here’s a 4-hour trend of NEM Mainland Grid Frequency on Sunday 12th October 2025 – from 09:00 to 13:00 (NEM time).
Two-shifting again at BW02 on Saturday 11th October 2025
Worth noting that Saturday 11th October 2025 saw Bayswater Unit 2 perform the two-shift shuffle again.