Cook Strait - Cables

Cables

Electric power and communication cables link the North and South Islands across Cook Strait, operated by Transpower.

• Power cables: Three submarine power cables cross Cook Strait between Oteranga Bay in the North Island and Fighting Bay in the South Island as part of the HVDC Inter-Island, which provides an electricity link between Benmore in the South island and Haywards in the North Island. Each cable operates at 350 kV, and can carry up to 500 MW, with Pole 2 of the link utilising one cable and Pole 3 utilising two cables. The link's capacity is 1200 MW, but restricted to 1000 MW due to inadequate voltage support at Haywards. The cables are laid on the seabed within a legally defined zone called the cable protection zone (CPZ). The CPZ is about seven kilometres wide for most of its length, narrowing where it nears the terminals on each shore. Fishing activities and anchoring boats are prohibited within the CPZ.

• Communication cables: Fibre optic cables carry telecommunications across Cook Strait, used by New Zealand’s main telecommunication companies for domestic and commercial traffic and by Transpower for control of the HVDC link.