The older they get …

After looking at South Australia for the last few issues, this week we turn our attention to our home state of New South Wales. The generation mix in New South Wales is dominated by five coal-fired power stations:

  • Eraring
  • Bayswater
  • Liddell
  • Mount Piper
  • Vales Point.

With tightening supply and demand, each of these power stations has become critical to reliability – anything that affects their availability has profound consequences when demand soars in summer. Most notably:

  • the potential closure of the Springvale mine triggered passage of legislation in New South Wales to ensure the coal supply to Mount Piper; and
  • the long-foreshadowed closure of Liddell became headline news in September, when the Prime Minister sought to negotiate with AGL to keep the plant open beyond its planned retirement in 2022.

Against this backdrop, this week we take a closer look at these 5 power stations which are so critical to electricity supply in New South Wales.

Chart 1: Overview of NSW thermal generation capacity by age of plant

Chart 1 provides a breakdown of thermal capacity in New South Wales. By way of explanation:

  • the size of each slice of the pie represents that nameplate capacity of the power station – larger slices indicate greater amounts of installed capacity; and
  • each slice is coloured by the age of the power station in years, where older plants are indicated in red and newer facilities in blue.

The chart shows that the 5 coal-fired power stations account for more than 3 quarters of thermal capacity. With the exception of Mount Piper, all of these power stations are at least 30 years old. Liddell is 45 years old.

Chart 1 – Five power stations account for over three quarters of thermal capacity in NSW

Thermal capacity in New South Wales by station, coloured by age of plant

Chart 2: Output of coal-fired power stations in New South Wales

So what have these power stations been doing? How have they been performing?

Chart 2 shows output (in GWh) from each of the 5 coal-fired power stations in New South Wales for 2013 to 2017. We have only included data for Q1 to Q3, which allows a comparison between 2017 and previous years. Eraring’s Q1-Q3 output has increased substantially in 2017. We note that Origin’s 2017 annual report cited steps that they have taken to improve their coal supply, enabling them to support higher levels of generation.

Chart 2 – Eraring’s Q1 to Q3 output has risen in recent years

Output for coal-fired power stations in NSW for first 3 quarters of the year – 2013, 2014, 2015, 2016, and 2017

Chart 3: Number of hours online

Finally, we look at the number of hours that each power station (or more precisely each of its units) has been online.

Chart 3 shows hours online for each power station, again for Quarters 1 to 3 for each year from 2013 to 2017. Note that Bayswater, Eraring, and Liddell each have 4 units; Mount Piper and Vales Point each have 2 units.

The striking feature of this chart is the increasing trend of time online for Liddell. For the first three quarters of 2017, Liddell’s time online is 60 per cent higher than during the same period in 2013.

Chart 3 – Liddell time online in 2017 is 60 per cent higher than during the same period in 2013

Time online for coal-fired power stations in NSW for first 3 quarters of the year – 2013, 2014, 2015, 2016, and 2017

Our two cents

  • Charts 2 and 3 show that Origin is running Eraring hard. In the first 3 quarters of 2017, Eraring generated 13.6 TWh of energy and their units have been online 94 % of the time. Slow down – we’ve still got summer to come!
  • The National Energy Guarantee establishes an explicit requirement for retailers to contract for megawatts of dispatchable generation. Chart 1 shows that there is a huge variation in the age, and so reliability, of each of the power stations in New South Wales. Will the NEG treat all dispatchable megawatts equally? Or are some dispatchable megawatts better than others?

As always, all comments are most welcome.