Asset safety and reliability
Hydro Tasmania expends significant capital keeping its assets safe and reliable. This year’s major capital expenditure was on projects for Catagunya Dam and the Lake Margaret, Poatina and Tungatinah power stations, see figure 9.
The Catagunya Dam is a $38 million project, replacing corroded post-tensioned cables to ensure the future stability of the dam and improve flood handling capability. Construction started in the summer of 2008/09 and is expected to be complete in summer 2010/11. It is a key element of the Dam Safety Program.
The Lake Margaret project involves modernising and recommissioning the station, which was closed in 2006. Construction on the $14.7 million project started in October 2008 and is expected to be completed in October 2009. The redeveloped power station will add 50 GWh to the system when commissioned. In addition, a mini-hydro power station was planned in 2008/09 for Lower Lake Margaret. When this is complete in 2009/10 it will provide a further 20 GWh.
The Poatina project continued the modernisation of three machines, which started in 2007 and will continue into 2010, with a total cost estimate of $53 million. When completed, this project will result in improved reliability, more efficient maintenance routines and safer working conditions, and will ensure compliance with NEM system requirements. It will also add 30 GWh to the system.
The Tungatinah project involves modernising three of the five machines at the power station to address operating risks. The project cost estimate is $71.8 million. This year, the planning, design and procurement work was all but completed. Construction work will start in 2009/10. When complete, this project is expected to add 9 GWh of energy to the system.
Our major system improvements for safe assets included upgrades to the primary protection system and the protection and control program. This investment will contribute to plant and personal safety and the life-cycle risk management of the assets, and contribute to improved reliability.
We continued to implement the primary protection testing program. The works completed in 2008/09 contributed to a lift in compliance from 87 to 94 per cent. We also implemented the protection and control upgrade program, starting work on the John Butters and Anthony power stations, and progressing design and procurement for the Mackintosh and Bastyan power stations.
1000 GWh project
The 1000 GWh project addresses the challenge posed by the decrease in our system’s capacity. Hydro Tasmania initiated the 1000 GWh project in 2007/08 to identify and implement developments within the existing hydropower system to increase system capacity.
By 30 June 2009, it had created an additional 30 GWh of capacity as a result of the Lake River pipeline and progress on the Poatina Power Station upgrade.
A further 50 GWh capacity will be created in October 2009 with the commissioning of the Lake Margaret Power Station redevelopment.
Our aim is to create the first 425 GWh of additional capacity by 2015. This will largely be achieved through a series of mini-hydro installations, power station upgrades and water diversions. These projects are expected to cost around $180 million. After 2015, we expect to pursue machine upgrades and dam raising opportunities to bring the total to 600 GWh. Further work will take place in the following year to identify the remaining 400 GWh of additional capacity.
As noted above, our dam safety risk management procedures are supported by emergency management plans, which are regularly reviewed and maintained, to respond to a broad range of events.
An external review of our emergency management plans – particularly the links with other entities and the Tasmanian Electricity Emergency Management Plan – was undertaken on behalf of the Tasmanian Economic Regulator. This review found the plans to be well developed and robust, and demonstrate that Hydro Tasmania is well prepared to contribute to continuity of electricity supply in Tasmania during an emergency event.
We reviewed our dam safety emergency plan, which resulted in more clearly defined roles and responsibilities for management and operations and the alignment of the roles with the current business structure. We continued to implement our Dam Safety Program, which ensures our dams do not pose an unacceptable social or business risk. We undertake constant monitoring and regular risk assessments to ensure our legislative and duty of care obligations are met. The program includes training in dam safety awareness, surveillance practices and emergency response.
No public safety or significant environmental incidents associated with Hydro Tasmania dams were reported during 2008/09.