P - Transmission

AECOMPuketoi Wind Farm Technical ReportExecutive SummaryMighty River Power Ltd is currently proposing to build a new wind farm in the Puketoi Ranges approximately40kms south east from Palmerston North. The proposed wind farm is to contain up to 53 turbines, each with up to6.15 MW generating capacity. Electricity generated will be collected by combinations of 33kV overhead lines andunderground cables and then fed into the national grid via a 220kV overhead transmission line.AECOM has been engaged by MRP to provide details of the transmission system to be used to connect thePuketoi Wind Farm to the Turitea Wind Farm and the national grid.Transmission line and internal reticulation design has taken into consideration line capacity, transmission voltage,clearance height of wires from the ground, structural loading, electrical earthing, electrical field and magnetic fieldlevels.A 39km long 220kV overhead line is proposed between the Puketoi Wind Farm and the Turitea Wind FarmPlantation Substation. It has been designed to provide for a single transmission solution for the Puketoi WindFarm and other generation projects in the wider Puketoi area in order to reduce costs and environmental effects.The proposed 220kV overhead line comprises two circuits supported by both steel lattice structures and single ordouble steel pole structures with a combined total of 111 structures with a maximum structure height ofapproximately 52m.Electricity generation from the proposed wind turbines is collected using a system of both underground and aerialcables at a voltage of 33kV. The aerial 33kV collection system lines comprise single, double and triple polestructures supporting single, double and triple circuits, and will extend for approximately 23kms. The proposed33kV line routes comprise of 166 structures, with a maximum height of 22m.A new 33/220kV on site substation is to be located below the summit of the Puketoi range in order to connect the33kV collection circuits and to step the voltage up to 220kV for connection to the national grid.27 July 2011