Central NSW transmission line completed

TransGrid will energise its new 330 kV transmission line built between Wollar and Wellington in March, a $147 million project to increase the reliability of supply to residents and businesses in the central west of NSW.

The Wollar to Wellington line is TransGrid’s first major steel structure transmission line since the completion of the Queensland National Interconnector in 2000. The new line stretches for 115 km and connects Wellington substation 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,” TransGrid general manager of network development, Peter McIntyre said.

“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, in order to increase the reliability of supply to the area.”

The new Wollar substation was energised on 14 January, 2010 after 15 months of construction.

Prior to the new line being constructed, Wellington was connected to the National Electricity Market via a single 330 kV link and four 132 kV connections. The construction of a second 330 kV connections means TransGrid can now 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.

“Once energised, the new transmission line will increase the security of supply to the region, with the capacity to supply around half a million average homes,” Mr McIntyre said.

TransGrid manager of projects, Don Paton led a team of project managers, engineers, consultants, contractors and designers tasked with building the new line.

Preparations for the Wollar to Wellington project began with the selection of a study area between Wollar and Wellington, which included areas surrounding Beryl, Gulgong and Ulan.

“The study area for the transmission line avoided densely populated areas and was selected on the basis it balanced environmental, social and economic constraints of building a transmission line between Wollar and Wellington,” Mr Paton said.

TransGrid also strengthened their ongoing partnership with Greening Australia by commencing the Molong Grassy Woodland Community Restoration Project.

After 11 months of building, two new transformers were delivered to the completed Wollar substation during September 2009, marking the beginning of the final phase of the substation’s construction.

“Each transformer weighed approximately 125 tonnes, was over 85 m in length and was moved using three prime movers, police and pilot vehicle escorts,” Mr Paton said.

Since the transformer delivery, the project team’s activities have included

commissioning and testing, as well as taking students from the local Wollar public school on a tour of the new substation.

“The excursion with the local school children to the new Wollar substation helped satisfy all their curiosity about the construction movements which have been taking place over the past two years,” Mr Paton said.