Vales Point joins the coal team’s growing injury list

The Vales Point coal fired generator in NSW has joined the growing injury list among the nation’s coal generators, with a generator fault taking out one of its two 660MW units for more than a month.

The unit broke down in early April when – according to insiders – a hydrogen leak was found into the cooling water to cool the generator windings.

It meant that the generator had to be pulled apart and rebuilt, along with a new rotor alignment, and it is expected to be at least another few days before it is back on line.

The incident at Vales Point is just the latest in a series of major outages at the country’s remaining coal generators, which apart from becoming increasingly expensive to operate, and proving more and more unreliable.

Some of the recent incidents were outlined in the latest Quarterly Energy Dynamics report prepared by the australian Energy market Operator, which pointed to coal outages, and its bidding practices as being the major cause of a jump in electricity prices.

It noted increased unplanned outages at both Callide C and Kogan Creek Power Stations reduced output by 355 MW and 207 MW respectively in the first quarter, and the Callide C Unit 4 has been out since its exploded in the middle of last year.

Kogan Creek – the main grid’s biggest and most modern generator – was out of service for around 26 days due to an unplanned outage during the quarter.

It noted lower availability at the Mt Piper coal generator in NSW due to increased outages, coupled with units shifting offers from lower priced bands to bands above $60/MWh, reduced average output significantly by 360 MW to 583 MW this quarter.

Most notably, AEMO said, Unit 2 was taken out of service on 28 February for a major planned maintenance program that is expected to span up to three months28 . •

It also noted Unit 3 at Bayswater in NSW went out of service on March 4 for a major maintenance and upgrade program to increase unit capacity from 660 MW to 685 MW.

It was an equally grim picture with the dirtier brown coal generators in Victoria. AEMO noted that higher unplanned outages were one of the key drivers of lower brown coal output, coupled with increased low and negative daytime spot prices.

Yallourn’s output fell to its lowest first quarter output since the creation of the NEM due to increased outages – on average, Yallourn units were on outage for 20.5 days this quarter compared to 12.5 days in Q1 2021.

Towards the end of the quarter a small fire at the Units 3 and 4 station coal bunker area at Yallourn impacted the operations of the two units.

Since then Loy Yang A has been taken out of service after a dramatic failure that will cost AGL at least $73 million and take it out of the market until at least August.