Line route options

In response to Grange's request to be connected to the grid, Western Power investigated and discarded a number of line route options before deciding on the current alignments.

Option one

Connecting a transmission line from Muja directly to Southdown (not passing through Kojonup)

Western Power explored the option of going directly from Muja power station to Southdown. However, to secure future power supplies in the lower southwest, we were considering building a terminal substation in Kojonup. Routing the line through Kojonup would make it possible for us to connect the substation to the grid.

Option two

Undergrounding the transmission line between Kojonup and Southdown

This option examined the possibility of undergrounding the 220 kV transmission line between Kojonup and Southdown. The cost of undergrounding 220 kV lines is approximately seven times greater than building overhead transmission lines pushing the cost of building the line well over the $1 billion mark, making the mine uneconomical.

Option three

Dual circuit lines from Kojonup to Mount Barker with deviations south to Albany and east to Southdown

This option included a 220 kV line from Muja to Kojonup. From Kojonup a 132 kV line and a 220 kV line would run on the same set of towers (the 132 kV on the one side of the tower and the 220 kV on the other on what is called a dual circuit line) to Mount Barker. At Mount Barker the 132 kV line would continue south to Albany and the 220 kV would deviate east to Southdown.

This option was not chosen because this route requires the transmission line to run directly between the Stirling Ranges and the Porongurups and is a significantly longer line route.

Option four

Dual circuit from Kojonup directly to Albany, with a deviation from Albany to Southdown

This line route is similar to option 5. However, this option differs where the dual circuit line continues from Kojonup as far as Albany and does not deviate at Mount Barker. The deviation now runs east from Albany to Southdown.

This option was not pursued, as the line route is 60 km longer than the other options available, therefore significantly increasing the overall cost of the line.

Option five

Onsite power generation

Grange Resources explored the possibility of using onsite power generation. This option was discarded, as it is extremely expensive. Diesel-powered generators also emit significant greenhouse gasses. Grange Resources can be contacted for more information on the process they followed in determining why wind power and bio fuel power were not chosen.

Investigating alternatives for Grange Resources

GHD's investigations of the two potential line routes between Kojonup and Borden concluded in March 2007.

The information below was gathered from community consultation recommendations. The line route south of Gnowangerup was the preferred route. This line route was referred to the Environmental Protection Authority and gained approval in August 2007 .

Western Power Field Officers have contacted landowners along the transmission line route to finalise and negotiate any line route changes.

See also:

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