Hydro Tasmania and Basslink have announced that the Basslink Interconnector, the 500MW cable linking electricity grids across Tasmania and Victoria, could be offline until mid-October 2019 while repair work is undertaken.
The cable bundle which is responsible for the interconnector’s energy transmission comprises a high voltage direct current (HVDC) cable, a low voltage metallic return and a fibre optic cable.
Basslink identified a failure in the low voltage cable (metallic return) which is believed to have caused the interconnector’s Direct Current Protection system to trip on the morning of 24 August.
The identified failure is located in an above ground section of the low voltage cable in the transition station in Gifford, Victoria. Basslink is currently preparing a plan for the repair.
Based on current information, Basslink said it has notified the Australian Energy Market Operator (AEMO) that the interconnector will be offline until mid-October. It also proposed further testing, which would better inform the return to service date.
Basslink said it will update the market with any changes to the proposed return to service date as repairs progress. At this point in time, the outage only affects the electricity interconnector. Basslink’s telecoms cable (providing broadband services to internet service providers) continues to operate.
Hydro Tasmania’s Acting Chief Operations Officer, Jesse Clark, said Tasmania has ample on-island resources to manage the situation.
“We have a world-class hydropower system that’s served Tasmanians well for more than a century, excellent wind power resources and the ability to run gas-fired generation if required,” Mr Clark said.
“While the news that Basslink could be offline until mid-October is not ideal, it won’t cause any energy security concern for Tasmania.
“On the back of good winter inflows, Hydro Tasmania’s storages are at a very healthy level of 45.5 per cent, which is well above the High Reliability Level.”