By day, CS Energy’s power stations and Brisbane Office are busy places where hundreds of people work. But that changes at night, when only skeleton crews remain to continue our core business of generating and selling electricity.
Australia’s National Electricity Market (NEM) is a 24-7 operation, and so too are CS Energy’s power stations and our electricity trading desk.
While most of Australia sleeps, employees at our sites, along with other energy companies, continue the essential work of providing a stable electricity supply.
CS Energy sells electricity into the NEM from the power stations we own – Kogan Creek, Callide and Wivenhoe – as well as electricity generated at Gladstone Power Station for which we hold the trading rights.
Maintaining electricity supply
Our coal-fired power stations Kogan Creek and Callide are low-cost baseload generators, which means they operate continuously day and night. Key operations employees at these sites work in cycles of day and night shifts, swapping over at 6.30pm and 6.30am.
Michael Dignan is a Shift Supervisor at Kogan Creek Power Station, which has Australia’s largest single generating unit. At 750 megawatts, the Kogan Creek unit can generate enough electricity to power almost one million homes.
When he is on night shift, Michael supervises a small team of Production Control Officers (PCOs). The PCOs, or ‘operators’ as they are known in the industry, work out of the Kogan Creek control room and manage the power station’s output via a highly sophisticated control system.
Above: The control room at Kogan Creek Power Station.
Michael said a night shift would start with a handover meeting where the previous shift would brief his team on how the unit had performed and any plant issues to keep an eye on.
“Our role is to ensure that we operate the generating unit safely, reliably and within its environmental limits,” Michael said.
The Shift team balances their time between the Control Room and going out on the plant to complete routine inspections, follow up any operational problems and complete equipment safety isolations in preparation for maintenance activities the following day.
“Any change in the power station’s output has to be carefully managed with CS Energy’s night trader in Brisbane so that CS Energy fulfils its market and contract obligations.”
The other people on site will be security, and, depending on the maintenance schedule, some maintenance personnel.
Above: A Shift Supervisor does a plant inspection at Kogan Creek Power Station.
Maintenance work on CS Energy power stations is generally carried out during the day and planned well in advance. But, like a car, power station equipment can unexpectedly break down at any time of the day, so maintenance personnel take turns being rostered on call at night.
Craig Campbell is a Senior Tradesperson at Callide Power Station who participates in an “on call” roster of intervals of approximately one week per month.
“There’s always one mechanical tradesperson, one utility worker and two electrical tradespersons on call at night. This allows for most contingencies to be managed,” Craig said.
“The frequency of the calls varies. I’ve been on call some weeks and never had a call and other weeks you can be quite busy. It depends on the condition of the plant and coal quality.
“If we receive a call from the Shift Supervisor we know that they’re calling for a good reason. They don’t enjoy waking people up at 2am.”
When a unit is overhauled every three to four years, maintenance is done around the clock for up to 10 weeks. Craig has filled the role of Night Shift Coordinator on several overhauls, supervising overhaul contractors and carrying out quality inspections.
“I find that everyone is very focussed at night,” he said. “Because it’s dark you sometimes lose track of time. People really get in the zone.
“Working nights is not for everyone, but I enjoy it.”
Above: Overhaul workers in the Callide Power Station turbine hall during the Unit B2 overhaul in 2018.
Managing the trading desk
Meanwhile, in CS Energy’s Brisbane Office a night trader manages CS Energy’s portfolio in the NEM and keeps in regular contact with the power station operators.
Physical Trader David Bliss said the “nights aren’t that much different to the days – it just tends to be quieter”.
“Our workload ebbs and flows depending on plant reliability and market conditions,” David said. “It’s still a five-minute market, the same as during the day,” David said. “The Australian Energy Market Operator (AEMO) determines the wholesale electricity prices every five minutes depending on supply and demand at that point in time.
Above: The National Electricity Market operates around the clock.
“Once the night time peak ends at around 10pm, demand and prices are typically lower until the morning when people wake up and get ready for work and school.”
Market conditions can change overnight if there is scheduled and non-scheduled maintenance, and unit availability changes in the NEM.
During the night, David will be in regular contact with the power station operators about the plant conditions, how the units are performing and whether any maintenance is required during the shift. Portfolio dispatch for that night and the following day is analysed and compiled, then bids are adjusted where necessary and sent to AEMO.
“For example, if a coal mill at one of the thermal sites needs to be worked on, we’ll coordinate the best time, if possible, for that to occur based on market price and station manning capabilities. This allows us to bring on or increase load from other generating units to cover the shortfall and minimise financial impact,” David said.
Like their colleagues at the power stations, the traders alternate between night and day shifts for set periods to manage fatigue.
“Sometimes it can be lonely working by yourself at night, but I also like the flexibility of being at home during the day and being able to spend more time with my kids at the times you don’t get with working 8am to 5pm.”
Acknowledgement: This story was inspired by an article by UK energy company Drax about the night shift at Drax Power Station in North Yorkshire.