GPO Box 7077, Riverside Centre,
Brisbane, Qld Australia 4001.
Level 11, 77 Eagle Street
Phone: (07) – 3211 – 8614
Fax: (07) – 3211 – 8619
24 August 2001
Basslink Joint Advisory Panel,
C/- Dept of Infrastructure,
Traralgon Office,
120 Kay Street,
Traralgon, Vic 3844.
Dear Sir,
Re: Submission on Basslink
TransEnergie Australia Pty Ltd (TransEnergie) is pleased to provide this submission to the Basslink Joint Advisory Panel on the Basslink project.
Background
TransEnergie Australia Pty Ltd is a subsidiary of the Canadian utility Hydro-Quebec. Within Hydro Quebec TransEnergie is the owner of extensive transmission assets consisting of both ac and dc facilities ranging in voltage from 49 kV to 765 kV, and with a total length of over 32,000 kilometers. In 1998 the value of TransEnergie’s transmission assets exceeded $US12.2 Billion. Outside of Canada, Hydro Quebec also owns and operates transmission networks in the United States, Chile and Australia.
TransEnergie has extensive experience in the development of network services within Australia. For example, TransEnergie has developed the 180 MW Directlink interconnection between the New South Wales and Queensland electricity markets, and the 220 MW Murraylink interconnection between the Victorian and South Australian electricity markets which is presently under construction, with commissioning due for April 2002. TransEnergie is also developing a number of other interconnection projects in the Australian National Electricity Market (NEM) eg Southernlink and Snowylink.
TransEnergie is therefore well qualified to comment on the Basslink project.
TransEnergie’s Comments
TransEnergie wishes to comment on the following aspects of the Basslink project:
- The use of mono-polar dc technology with sea electrodes,
- That Basslink is proposed to be developed overhead through Victoria, and
- The 600 MW capacity of Basslink.
The Use of Monopolar Technology with Sea Electrodes
TransEnergie notes that Basslink:
‘will be a 400 kV, direct current (DC) mono-pole electricity interconnector, with sea electrodes either side of Bass Strait’.
There are a number of serious environmental issues related to the use of sea electrodes, and these can be summarized as follows:
- As the sea electrode has a slightly higher voltage potential than the ground there is a voltage drop in the ground around the electrode. Depending on actual soil conditions, this region can be quite small, or quite large. Any other metallic structure in this region (such as pipelines or other armored cables) will have additional corrosion due to this voltage drop. If the region extends up to land it is also possible that other minor problems may appear.
- Electrolytic reaction at the anode:
- There will be some chlorine release at the anode. The total amount released from a 600 MW electrode would be of the same order as the water cleaning plant of a small city.
- Compass deviation may be significant in shallow waters.
As a result of such problems it is understood that no new European projects will be permitted to employ sea electrodes. For example, the SwePol link was originally proposed with sea electrodes, but these were replaced with a return cable due to environmental concerns. The new Norwegian HVDC projects under development (NorNed to Holland and Viking/Euro to Germany) will also not use sea electrodes.
In addition, the United States of America National Electric Safety Code (ANSI C2) prohibits the use of the earth as the low voltage current return path. On that basis TransEnergie considers that Basslink should not be permitted to employ sea electrodes.
The Use of Overhead Lines
TransEnergie notes that Basslink’s preferred Victorian construction is an overhead route along the Old Rosedale Road. Further, TransEnergie notes that:
‘the Old Rosedale Road underground route achieves the best biodiversity and amenity results but at a high cost that renders the project commercially infeasible’.
TransEnergie does not understand nor agree with this statement.
TransEnergie’s Australian projects have been developed with a focus on minimizing environmental impacts, while at the same time ensuring that the projects are commercially viable. Key to the success of this strategy has been the use of the latest dc technology developments. This has served to reduce environmental permitting requirements and thereby facilitate ‘speed to market’. For example, both the Directlink and Murraylink interconnections have employed the latest HVDC Light technology developed by ABB Power Systems AB of Sweden.
Advantages of this technology include that TransEnergie’s interconnections require no overhead transmission line components. For example, the Murraylink interconnection, presently under construction between Victoria and South Australia, will be 180 kilometers in length, and yet will require no overhead transmission line i.e. Murraylink will be underground for its entire 180 kilometers. Whilst that will establish Murraylink as the longest underground transmission line in the world, it does not represent a constraint limit on the technology.
TransEnergie does not consider that the cost of undergrounding is exorbitant, as implied in the report. Rather, TransEnergie considers that recent technology developments mean that the total costs (including permitting) of underground versus overhead developments are now in many cases comparable.
TransEnergie therefore considers that there are commercially viable options for the undergrounding of the Victorian component of Basslink.
Basslink’s capacity
TransEnergie notes that Basslink is to be developed with a sustained capacity of approximately 480 MW, but that in addition Basslink will have a short term capacity of up to 600 MW.
TransEnergie is not aware of the basis of the planned 600 MW capacity. However, it is noted that this capacity has the potential to lead to significant changes in Tasmanian stream flows. On that basis the 600 MW capacity may not be optimal from the environmental perspective. TransEnergie does however note that the optimal capacity for the traditional technology proposed for Basslink is 600 MW.
Recent technology developments mean that Basslink could be economically developed now as a staged project with (for example) an initial capacity of 300 MW, and an option to increase at a later date to 600 MW should further studies show that the environment is able to support the increased capacity.
Conclusions
TransEnergie considers that as proposed Basslink is employing out of date technology that has potential for significant adverse environmental impacts. This is demonstrated by the fact that the proposed technology is no longer permitted in Europe or North America.
TransEnergie considers that the use of the latest dc technologies would mitigate many of these adverse impacts. For example, TransEnergie is employing such technology to develop the Murraylink interconnection as the longest underground interconnection in the world at 180 km in length. This length does not represent a constraint (technically nor economically).
On that basis TransEnergie considers that there are significant environmental issues that the Basslink ‘Integrated Assessment Statement’ has not addressed.
Regards,
Dr. A. Cook
Managing Director