Penrose, Glen Innes, East Tāmaki, and Ōtāhuhu. Improving security of supply The incident at Otahuhu in June 2006 had a major influence on subsequent decisions about the development of the grid. On 11 December 2006, the Electricity Commission (NZ) received an application from Transpower for the establishment of a new 220 kV gas insulated switchgear (GIS) facility at Otahuhu, adjacent to but geographically separate from the existing outdoor 220 kV switchyard. This project was described as the Otahuhu substation diversity project, and included transferring approximately half of the circuits from the existing switchyard to the new GIS switchyard, to improve network resilience. The project was approved in August 2007. Further steps have been taken to increase security of supply to Auckland, by reducing the dependence on Otahuhu. These include the diversity provided as part of the North Island Grid Upgrade Project by connecting the new Whakamaru to Brownhill Road transmission line to Pakuranga substation, rather than directly to Otahuhu. A second major project, the North Auckland and Northland grid upgrade project provides underground 220 kV cables from Pakuranga to Penrose, and from Penrose to Albany on the North Shore, via Hobson Street in the Auckland CBD. A 220 kV- capable overhead transmission line between Pakuranga and Otahuhu has also been upgraded from 110 kV to 220 kV. See also 1998 Auckland power crisis List of power outages Whakamaru to Brownhill Road transmission line North Auckland and Northland grid upgrade project References Power outages in New Zealand Auckland Blackout, 2006 Auck Auck 2000s in Auckland Electric power transmission systems in New Zealand Auck June 2006 events in New Zealand