Summer has just started and for Australia, that means it’s the peak demand period for electricity, as more and more people switch on the air conditioning to beat the heat.

But it’s not just the peak demand – summer places an enormous strain on both our energy generation infrastructure and the people who maintain it. Thousands of dedicated people will work throughout the summer and holiday period in tough conditions to make sure our system is as resilient and reliable as possible.

Across Australia, an enormous amount of time and effort goes into grid stability and meeting peak demand over the summer period. AGL provides an essential service to the community, so it’s critical that we plan for the peak periods and do everything in our power to keep the lights – and the AC – on.

Planning ahead

Preparing for the summer period begins early on – at the end of the preceding summer, in fact. We take the lessons learned from the previous summer, along with any known issues from our plants, and build a summer preparedness plan at each major site.

At AGL, we are doing everything we can to make sure our generation sites are ready for summer. As some of our generation sites are older, the planning and preparation for this is paramount. The wider grid is managed by the Australian Energy Market Operator, whose role it is to operate the market to deliver energy when its needed.

This is the ninth year of summer preparedness. Each year the bar rises – and so too does our planning and preparation. For the 2019-20 summer period, $150m is being invested in summer preparedness.

Preparations at AGL Macquarie and AGL Loy Yang

Head of Liddell Generation, Seth Pathiyil, explains.

‘Being in total control of our assets is fundamental through this journey,’ Seth said.

‘We’re following a rigorous process for summer readiness by implementing the lessons learnt from previous years, carrying out summer readiness outages, identifying key risks, and ensuring mitigating controls are in place.

‘The aim is to achieve the desired availability of 420MW on all units at Liddell through the summer months – with clear plans in place to deal with unexpected availability issues should they arise.

‘We aim to deliver maximum capacity on very hot days by ensuring we check and carry out maintenance on those elements that will be most affected by high temperatures, such as coolers and heat exchangers.

Proactive outages are planned in advance of the summer period to make sure that sites are as ready as they can be. For example, each unit at Victoria’s Loy Yang A power station has been taken out of service for a summer preparedness outage. Around $66m has been invested in Loy Yang’s summer preparedness program alone.

We also take advantage of forced outages to work opportunistically: for example, Loy Yang A’s Unit 2 has been out of service since May 2019 following an electrical short and the unit is expected to return to full service mid-December before the peak summer period commences, after $57m in works – including upgrades.

How do renewables and flexible generation contribute to the summer peak-period?

Australia's energy mix is evolving with the rise of increasing utility-scale renewables and rooftop solar. This has changed the energy demand profile into a much peakier proposition.

This change in the traditional supply/demand dynamic has also spurred the development of capacity that provides support for, or ‘firms’, renewable energy. This is flexible energy supply that can be activated at a moment’s notice to top up supply when it’s needed most.

South Australia’s Torrens Island Power Station (TIPS) and the new $295m, 210MW Barker Inlet Power Station (BIPS) are examples of firming capacity. TIPS has seen a $5m summer preparedness investment, while the new BIPS is expected to be capable of generating at full capacity by 13 December 2019. Better still, BIPS is capable of reaching full capacity within five minutes.

And importantly, at Torrens Island, we have also deferred the mothballing of several of the TIPS A generation units, so that they will operate over summer. This will significantly boost capacity for South Australia over summer.

Beating the heat – in other ways

We have to be prepared. The bushfires that have raged – and are still going – across NSW, Queensland, Victoria, and South Australia are a sobering reminder of what other concerns the summer period presents.

Fire audits have been carried out across sites as part of summer readiness. Head of Bayswater Generation, Kevin Taylor, explains.

‘Liddell and Bayswater sit on some 10,000ha of land, so summer condition readiness is important too,’ Kevin said.

‘We are slashing ground-cover to reduce the amount of combustible material; we are ploughing fire breaks; we are carrying out training in fire management; and we are making sure we’ve carried out maintenance on all fire equipment and infrastructure.’

AGL’s fire infrastructure runs the full spectrum from fire extinguishers and sprinklers, cooling sprays and auxiliary cooling of plant, right up to enormous fire control infrastructure like DWPS11.

The Loy Yang fire control system is capable of moving a very deep Olympic-sized swimming pool’s worth of water to the equivalent height of Melbourne’s Eureka Tower – in just fifteen minutes.

Summer readiness – at a glance

National summer readiness investment: $150m


Summer readiness spend: $66m

  • Major outage and repair of Unit 2. A specialised crew of 40 are working around the clock to repair and upgrade the unit at a cost of $57m, which will come online mid-December 2019.
  • Planned outages to clean boilers, make critical inspections, and reduce the risk of potential forced outages.
  • Strict adherence to heat policy and fatigue policy for employees, such as ice vests, long rest breaks, and split crews to keep work moving forward.
  • Extensive fire risk mitigation for Loy Yang mine site is being rolled out and tested, including the creation of buffer zones and fire breaks, installation of infra-red cameras, readying emergency vehicles and mine spraying equipment, and training all personnel.

Summer readiness spend: $79m

  • Extensive body of work to deliver high levels of reliability, including planned outages, identifying key risks, and ensuring mitigating controls are in place.

Summer readiness spend: $5m

  • New $295m, 210MW Barker Inlet Power Station to come online to full capacity mid-December 2019.
  • Minor outages completed or nearing completion to ensure all eight units are available when required.
  • Life of Torrens Island Units A2 and A4 (combined capacity 240MW) extended to March 2020 and extensive inspections complete, significantly boosting SA’s capacity.
  • Drone survey, including photography and thermography, completed across wind farm sites.