Milestones
Kurri North Switching Station (KNSS) is complete. This switching station will be handed over to Ausgrid for their energisation of the facility by the end of August 2024. KNSS connects the two generators at HPP to the broader 132 kV network. It is how the power generated from HPP makes its way into the National Electricity Market (NEM).
At Gas Turbine One (GT1), all three phases of the Isolated Phase Bus (IPB) have been connected from the Generator Step-Up Transformer (GSUT) to the Generator Circuit Breaker (GCB). The HPP team aims to extend the connection from the GCB to GT1 by mid-September 2024. This is an important milestone for HPP with the IPB on the critical path. The IPB carries the power from the Gas Turbine Generator to the GSUT, which is where the power lines start for the transmission.
Grouting and final alignment of GT1 is complete. Grouting is a six-step sequential process and ensures mechanical equipment has a smooth contact surface for levelling and alignment. The sequence is as follows: (1) generator/slip ring/turning device foundation bolts; (2) slip ring seating plate; (3) generator seating plate; (4) enclosure I-beam; (5) generator walkway; and (6) turning device seating plate.
Pressure testing for the diesel system, demineralised water system, fire water system and lube oil system has commenced. Pressure testing aims to check that the pipework is fit for service without any leaks in flanges, pipes or welds. All tests occur in a controlled environment to ensure the safety for the testing personnel. Pressure testing is performed well above the expected design pressure of the service to ensure any issues are identified.
The HPP team completed a walk down for the 132kV Control and Protection Room. This room is critical for commissioning HPP as it enables back-energisation of the power station from the grid later this year. It houses electrical protection equipment that protects the transmission lines, feeders and generator transformers from electrical faults. It also contains the metering equipment that measures electrical output from the power station for revenue purposes.
The Control and Administration building, which houses the central control room and distributed control system (DCS), was completed in April 2024. This building is where the future operations and maintenance team will be based. However, there will be a hive of commissioning activity for the DCS for the next few months. The DCS is the ‘brain’ of the entire power station, and all plant functions require verification and testing by the DCS using a visual representation of the facility.
The installation of the Hunter Power Project’s SFC Buildings was a multidisciplinary team effort that required careful planning. The buildings weigh 24 tonnes each and were transported more than 1,500km on a three-day journey from Adelaide before arriving to site in August 2023. The installation took place in an area where Simultaneous Operations (SIMOPs) is vital and attention to detail is required. SIMOPs involves supervisor and trade interactivity on the ground for the coordination of effort and safety. This is a key milestone – unit 1 is on the critical path and is important to the project’s commissioning portion.
The installation of the Hunter Power Project’s Fin Fan Coolers has been successful. These closed-loop cooling systems weigh 30 tonnes each and are essentially air-cooled heat exchangers (ACHE). The process fluid enters the ACHE through inlet nozzles, passes through the tube bundle, and exits through outlet nozzles, cooling down as it transfers heat to the surrounding air. The tube bundle is cooled from air forced through by fans driven via electric motors. At HPP, each gas turbine has a dedicated closed-loop cooling water system. These systems circulate demineralised water treated with corrosion-inhibiting chemicals to cool the following equipment:
June 2024
In the civil space at the Hunter Power Project, most services – including trade waste, stormwater systems, oily water systems, fire ring mains, and mechanical services – are completed in the ground. All concrete slabs in GT1, GT2, and Balance of Plant areas are completed except for some minor pipe supports and trenches, infill slabs, and light pole foundations. The civil team will now work on the finishing touches to site with infill pavement slabs, earthworks for pavements, and remaining pits and bollards.
June 2024
All four Balance of Plant Tanks have been completed and passed their hydrostatic tests. This involved filling the tanks with water to ensure there were no leaks. Each tank is approximately 11 metres high, with an internal diameter of 15 metres, and has a capacity of 1.944 million litres. When full, the total weight of each tank is 1,993 tonnes. The Service Water Tank is for potable water used across the project, while the Demineralised Water Tank will hold demineralised water of extremely high purity for use in the power generation process. It took 46 B-double trucks delivering 42,000L of water each from Colongra Power Station to fill the Demineralised Water Tank (third from left in image). The total travel distance of this two-week process was 5,520km or HPP to Perth and almost halfway back. All four tanks will now be handed over to the commissioning team, who will start filling the remaining tanks with diesel to be used for commissioning of the turbine. These diesel tanks will hold the back-up fuel to keep the turbines going when gas is not readily available.
It requires teamwork, precision and specialised transport to get our huge Snowy 2.0 power station components safely to site. Delivery of the largest and widest loads occur at night for safety reasons and to minimise disruption to the public. Two prime movers pull and one pushes the 7.5 metre wide and 156-tonne spiral case, escorted by pilots and the police.
The Snowy 2.0 Cooma precast manufacturing facility hit another significant milestone and completed production of 100,000 of 130,000 tunnel lining concrete segments. More than 230,000m3 (or more than 550,000 tonnes) of concrete was used to manufacture these seven-tonne precast segments, installed by tunnel boring machines used on the Snowy project.
