Callide catastrophe sparks calls for big batteries

A fire at the Callide C coal-fired power station on Tuesday caused chaos in Queensland’s electricity system with an estimated 477,000 homes and businesses from Cairns in the north to the Gold Coast in the south left without power.

CS Energy, the state government-owned energy company which operates the 1.5 GW Callide Power Station near Biloela in central Queensland, said a fire had occurred in one of the turbine halls at the plant just before 2pm on Tuesday.

CS Energy said the event had immediately forced both units at Callide C offline. That caused such instability that all operating units at Callide B also tripped.

The Australian Energy Market Operator (AEMO) said the “significant power system event” had also tripped multiple transmission lines and forced power stations at Gladstone, Stanwell, Yarwun and Mackay offline, resulting in about 3.1 GW disappearing from the Queensland grid.

A Powerlink spokesperson said the impact occurred within milliseconds of the incident at Callide.

The incident sparked outages across the state, blacking out hospitals, airports, shopping centres, sewage treatment plants, traffic lights, businesses and households. Most of those who lost power were back online within hours.

A spokesperson for New South Wales energy provider Essential Energy said tens of thousands of residents bordering the Gold Coast had also lost power but it was returned by 3.30pm.

In the wake of the incident AEMO issued a “lack of reserve” (LOR) notice at 4.45pm and a forecast LOR3 notice at 5.07pm identifying the potential for electricity demand to exceed supply in Queensland. It later called on households to avoid using heavy appliances to “minimise stress on the system” until at least 9.30pm to mitigate the risk of further brownouts or blackouts. This notice was later cancelled at 7.13pm due to sufficient power supply from generators returning to service around the state.

Queensland Energy minister Mick de Brenni said on Wednesday morning the grid had been stabilised and he was confident there would be no more outages linked to the plant fire.

“We don’t expect to see any blackouts as a result of this incident,” he said.

“The power in Queensland is stable. We worked closely across all agencies and with the national Australian Energy Market Operator to make sure they were able to bring on additional supply.

“We have a diverse and publicly owned generation network in Queensland – everything from nearly 700,000 households with rooftop solar, solar farms, wind farms, pumped hydro and a fleet of coal-fired generators and they’re all operating all full steam this morning.”

Queensland Conservation Council director Dave Copeman said the incident had reinforced the need for more utility scale batteries to be established within the state to shore up grid stability.

Copeman said Queenslanders want reliable cheap, clean electricity and the best way to guarantee it is by investing in renewable energy and storage such as large batteries.

“This illustrates the devastating impact that relying on large, geographically concentrated thermal coal units can have, particularly as they age,” he said.

“The piece of infrastructure transmission operators most needed when this failure occurred was a large-scale battery. It could have been delivering power to support the grid within seconds and may have prevented the wider network failures.”

Batteries have emerged as a critical component of Australia’s energy network with the Energy Security Board’s (ESB) Post 2025 Market Design Directions Paper stating the projected influx of new renewable energy over the next two decades will need to be supported by between 6-19 GW of new flexible and dispatchable resources.

Queensland already has a number of grid-connected batteries operating, including at the Lakeland Solar Farm (1.4 MW/5.3 MWh) in Far North Queensland, and one at the Kennedy Energy Park (2 MW/ 4 MWh) near Hughenden.

Those facilities are set to be bolstered with Singapore-based developer Vena Energy having already commenced construction of a 100 MW/150 MWh grid-scale battery near Wandoan in the Western Downs while AGL Energy plans to build a 100 MW/150 MWh battery next to the 453 MW Cooper’s Gap wind farm near Kingaroy.

French renewables developer Neoen is planning to build 150 MW of battery storage as part of its proposed 460 MW Western Downs Green Power Hub to be constructed near Chinchilla and has also submitted plans to develop a 100 MW battery project in Queensland’s far north.

The Queensland Government has also announced plans to install five large-scale, network-connected batteries, with a combined capacity of 40 MWh in regions across the state as part of a community battery trial.

Copeman said those batteries will be increasingly important as coal-fired power plants are retired.

Commissioned in 2001, the 825 MW Callide C is one of Australia’s newest coal-fired plants but Copeman said it the technology has failed to keep pace with the rapidly transitioning energy network.

“When Callide C was built in 2001, it was talked about as having a 25-year life span. It’s now 20 years old,” he said.

“Queensland coal has been forced to operate more flexibly than it was designed to as solar has entered the market in recent years.

“This potentially makes units more vulnerable to failure.

“Even if this incident was unrelated, it still shows the potential disruption to Queensland’s electricity supply possible in future.”

Rystad Energy senior analyst Dave Dixon said Queensland’s fleet of coal generators only has a very small ramping capacity, compared to Victoria and NSW. It can manage only 500 MW a minute, due to its reliance on coal, compared to more than 2.5 GW in NSW.

Dixon highlighted that batteries can ramp up to 100% of capacity in less than a second.

Investigations into Tuesday’s blaze have already commenced with CS Energy CEO Andrew Bills saying that an initial inspection had revealed unit C4 at Callide C, which is jointly owned by CS Energy and Intergen, had experienced major damage and failure of the turbine.

Bills said it will take some time to fully understand the cause of the failure and what will be required to repair the unit, but warned it could be a year before it is back online.

“It is too early to say with certainty when unit 4 will be operational again, however based on currently available information, we have informed the market operator this morning that the unit will be available in 12 months,” the company said in a statement.

“We are assessing the damage to other three units. This will be our priority today so that we can work out a plan to bring those units back safely.”