TransGrid completes $147 million transmission line project

A $147 million construction and commission project has recently been completed, providing a 115 km long 330 kV transmission line that will connect the Wellington substation in the NSW Central West to TransGrid’s 500 kV network, via a new 500/330 kV substation at Wollar.

“The main driver of the project was the steady increase of electricity demand in the central western areas of NSW,” said Peter McIntyre, General Manager of Network Development at TransGrid. “The purpose of the new transmission line was to create a second 330 kV link to our existing Wellington substation, a major bulk electricity supply point to the Central West, with the capacity to supply around 500,000 homes.”

Prior to the new line, Wellington was connected to the National Electricity Market via a single 330 kV link and four 132 kV connections. A second 330 kV connection now means TransGrid can overcome reliability concerns such as low voltages and thermal rating limits on the four 132 kV lines, which occur during scheduled maintenance of the existing 330 kV line.

The project began with the selection of a study area for the transmission line to avoid densely populated areas and balanced environmental, social and economic constraints. After extensive community consultation, TransGrid selected a preferred corridor for the proposed transmission line and commenced a detailed environmental impact statement. Construction then commenced February 2008 and included the erection of 277 individual ‘delta’ steel structures.

“Over 70 contracting and supervisory staff were required to complete the construction of the transmission line, specialising in foundations, access and vegetation management, tower erection and stringing,” said Don Paton, Manager of Projects at TransGrid, who led the team of project managers, engineers, consultants, contractors and designers to build the line. “TransGrid also appointed an independent environmental management representative prior to the commencement of any construction, to oversee the environmental considerations and constraints in building the transmission line.”

After 11 months of building, two new transformers were delivered to the completed substation. Each transformer was 85 m long, weighed 125 tonnes and was moved using three prime movers, police and pilot vehicle escorts.