Annual Planning Report 2012 - Transpower

Chapter 6: Grid Backbone6 Grid backbone6.1 Introduction6.2 Changes since the 2011 Annual Planning Report6.3 North Island grid backbone overview6.4 North Island grid backbone issues and project options6.5 South Island grid backbone overview6.6 South Island grid backbone issues and project options6.7 HVDC link overview6.8 HVDC link issues and project options6.1 IntroductionThis chapter describes the adequacy of New Zealand’s grid backbone to meetforecast demand and anticipated generation development, approved developmentplans, and further development options for the next 15 years.The grid backbone (see Chapter 3 for more information) provides the connectionbetween the regions. The regions are described in Chapters 7 to 19.Prudent transmission network planning considers a range of generation scenarios tomeet the forecast growth in demand (see Chapters 4 and 5 for more information) todetermine the development option and timing for grid upgrades.Transmission needs for the grid backbone are identified after the commissioning ofcommitted projects. The identification of transmission needs is indicative only, basedon a limited number of load and generation dispatch scenarios, along with the impactof future new generation scenarios. They indicate the possible need for a fullerinvestigation within the forecast period, with the timing and scope of the investigationdetermined by new generation developments and demand growth.The resolving projects to meet the transmission needs are an indicative list only,being possible solutions that will be subject to the Investment Test. They will bedeveloped through the grid planning process as investments to meet the GridReliability Standard and/or to provide net market benefit.For the North Island, the existing and possible future grid backbones are described inSection 6.3, with issues and possible grid upgrades described in Section 6.4.For the South Island, the existing and possible future grid backbones are described inSection 6.5, with issues and possible grid upgrades described in Section 6.6.The HVDC link is described in Sections 6.7 and 6.8. The Annual Planning Report(APR) assumed that the High Voltage Direct Current (HVDC) Pole 1 is replaced byPole 3 in 2012/13.6.2 Changes since the 2011 Annual Planning ReportTable 6-1 lists the specific issues and projects that are either new or no longerrelevant within the forecast period when compared to last year's report.Table 6-1: Changes since 2011Issues/projectsNo new issues or projects completed since 2011ChangeNo change402012 Annual Planning Report © Transpower New Zealand Limited 2012. All rights reserved.