An decommissioned underground substation under Dee street, which involves taking all the switchboard gear and transformers out of the underground substation, is expected to be completed over the next week.
PowerNet chief executive Jason Franklin said there were 12 underground substations in Invercargill which were at least 50 years old and they were replaced above the ground when they came to the end of their lives.
Above-ground substations were easier to maintain and safer to work on, Franklin said.
The Dee St underground substation had come to the end of its life when a switchboard fault in May resulted in “some smoke underground”.