The six sets of new 33kV high-voltage underground cables would take electricity from the national grid to substations on the Aurora Energy Dunedin network, Delta chief executive Grady Cameron said.
''These upgrades will future-proof electricity supply to 18,500 Dunedin consumers,'' he said.
''The existing cables are nearing the end of their useful life for high-voltage supply and use gas and oil as insulation, [which is] now an outdated technology. Modern cables use poletheylene plastic for insulation, removing the need to insulate using pressurised gas.''
The work started in December with the installation of 1.8km of PVC ducting to house the cables from the Andersons Bay substation to Portsmouth Dr.
The next scheduled upgrade was the Neville St substation by Carisbrook, Mr Cameron said.
