3 minute read

Keep on trucking to peaking power

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AGL Energy
02 July 2019

The first of three ABB transformers arrives at Barker Inlet Power Station

As Australia’s energy mix grows to include more and more renewable energy, peaking power plants like Barker Inlet Power Station are becoming increasingly important. Peaking power sources can be activated at a moment’s notice to support energy supply, and the electricity grid, during times of high demand.

The transformer is one of three to be installed at Barker Inlet Power Station, and delivering them was no mean feat. Each weighs 100t as is, with additional components to be installed on site to integrate them into the station.

They are being manufactured in Finland by Finnish company ABB; the first was shipped around the globe to Port Adelaide, where it was loaded onto a specialised transporter and brought to the site. They are being installed surrounded by giant blast walls, just in case the unthinkable happens and the transformers fail and catch fire. It is extremely unlikely that such an event would ever happen – but safety is paramount at the site.


The transformer being installed at the Barker Inlet site

How will the plant work?

The Barker Inlet Power Station will have around 210 MW of capacity which involves the installation of 12 reciprocating engines that can generate approximately 18 MW each from either gas and or liquid fuel. The units are capable of operating at full capacity within five minutes of starting, providing a rapid response to changes in renewable generation supply and demand.

This modern power plant will make a significant contribution to improving energy security in SA. It’s new technology, so it’s much more reliable than the ageing plant it will replace. The equipment is also much more efficient, requiring 28% less fuel (therefore 28% less CO2).

Artist impression of the completed Barker Inlet Power Station. The transformers are circled in blue

Responsive to demand

Barker Inlet Power Station is a peaking gas plant, which means it’s flexible in responding to demand, so it can more reliably match changes in wind generation and do so much more efficiently.


There are three categories of demand:

  • Baseload - demand that's there all the time, night and day, this has historically been provided by large gas or coal-fired thermal power stations.
  • Intermediate - additional demand on top of baseload when commercial and industrial users are active, this is now supplemented by renewable energy like wind and solar.
  • Peaking - usually occurs on very hot days when everyone's air-conditioners get turned on at the same time, this is can be met by gas reciprocating engines like Barker Inlet, open cycle gas, or pumped hydro.

What has prompted the increased need for peaking power?

The declining cost of utility (large) scale renewables has spurred its rapid development and so there is a greater need for highly flexible capacity which can be switched on or off according to the more variable needs of the market given renewables aren’t always available.

This increasing need for flexible and dispatchable energy, like gas peaking plants, is why gas is a critical part of an orderly transition to a clean and reliable energy supply.