Transpower's Line Service Providers. The boundaries and contacts for contractors in charge of Transmission Lines in each area. Transpower owns and operates the National Grid - the high voltage transmission network connecting areas of generation with towns and cities across New Zealand. The National Grid is made up of over 12,000 km of transmission lines and more than 170 substations. Electricity is transmitted over the grid at high voltages (up to 400,000 volts) from power stations to local lines companies and major industries.
