Transgrid trials innovative technique for recycling aged transmission lines

Transgrid is rolling out an innovative new technology that enables it to recycle spent transmission lines in situ, cutting the lifetime emissions of its infrastructure and saving money.

The transmission network company has partnered with German manufacturing firm ZECK, which created the technology, to recycle conductors in western Sydney.

The system works by feeding the spent conductors into a machine, the ZECK Al/Steel Separator (ZAS), under tension, which peels off the outer aluminium layer and cuts it into 30-70mm pieces ready to be smelted. The steel core is then wound onto a cable drum, ready for recycling.

The idea was pitched by Transgrid’s field coordinator Mitch Coppock. Just under two weeks into the trial, Transgrid has run about 40km of conductors through the machine, yielding about a kilogram of aluminium per metre of conductor.

“Something like that hasn’t been done in Australia before and being part of this initiative is exciting,” said Coppock.

“Anything innovative we can do is very important in our industry, especially anything that can have good long-term effects … and the environmental impacts this has are huge.”

In the past, conductors had to be shipped overseas to have their outer aluminium layer removed before the line could be recycled fully, at great cost and producing significant emissions.

Transgrid’s network includes 13,000 kilometres of high-voltage transmission lines across NSW and the ACT. Assuming the transmission lines are not impacted by external factors (such as bushfires or corrosion) the lifespan of a typical conductor is more than 90 years – but as the network is upgraded, more lines will need replacing.

Over the next five years Transgrid will replace an additional 785 kilometres of conductor.

Transgrid says this new technology could cut up to 90% of the emissions involved in recycling conductors.

“Everyone wins out of this solution,” said Coppock. “For Transgrid we can get a much higher return on the conductor as compared to current processes, the environment wins with reduced emissions and local businesses benefit too as they get readily available and processed aluminium.

“By taking out that overseas shipping we also guarantee the quality of labour that is used to process it, making it a more transparent and ethical process,” he added.

By eliminating the cost of offshore processing, Transgrid says it can can achieve a return of three times on scrap metal rates of up to three dollars a kilogram. Over the next three to five years, the technology is forecast to deliver upwards of two to three million dollars in extra revenue from recycling.