Many nations rely on coal, oil and natural gas to meet most of their energy needs. Fossil fuels are a limited resource. Fossil fuels also cause air, water and soil pollution and produce greenhouse gases that contribute to global warming. Renewable energy from sources that renew themselves as quickly as they are used. Examples include energy from the sun, wind, moving water, and plants. Wind and solar energy are clean energy sources that have the potential to make a significant contribution to New Zealand's economy. New Zealand is richer in renewable energy resources than developed countries, and much of its energy comes from harnessing energy stored in rivers, lakes and geothermal fields. Nearly a third of total energy consumed, including electricity, heat and transport fuels, comes from renewable sources. (http://www.teara.govt.nz/en/wind-and-solar-power/page-1). The 70% share of renewable energy sources makes New Zealand one of the countries with the lowest carbon dioxide emissions in relation to electricity production. Electricity demand has grown by an average of 2.1% per year since 1974 and by 0.6% from 2005 to 2011. Despite being slightly above the global range, New Zealand is called one of the least efficient countries from an energy point of view when comparing economic production with electricity consumption. (http://en.wikipedia.org/wiki/Electricity_sector_in_New_Zealand). New Zealand's economy relies on a range of energy types from a variety of imported sources. While the transportation sector is highly dependent on imported fossil fuels, the electricity sector in particular is highly dependent on imported fossil fuels, the electricity sector derives its primary energy sources from local sources such as hydroelectric and gas. (http://www.iscr.org.nz/f310, 14...... half of the document ...... the regions. As a result, we can plan future capacity on the backbone network with much greater certainty Identifying it now gives us the opportunity to determine strategies that will reduce the cost and footprint of providing this additional capacity and allows us to consider a broad range of technology options to deliver it well ahead of critical need dates and changes in demands regional connections may require significant additions to regional connections from the network backbone, but in these cases expansion of network capacity in regional connections is not necessary in every scenario increased capacity of existing lines or improvement in system performance with use of demand management could have added value in this case.