structural:scholar_edition, information:extraction
Tidal power

The electrical power generated by tidal marine turbines varies as the cube of the tidal speed. Because the tidal speed doubles, eight times more tidal power is produced during spring tides than at neaps. Cook Strait has been identified as a potentially excellent source of tidal energy.

In April 2008, Neptune Power was granted a resource consent to install a $10 million experimental underwater tidal stream turbine capable of producing one megawatt. The turbine was designed in Britain, and was to be built in New Zealand and placed in 80 metres (260 ft) of water, 4.5 kilometres (2.8 mi) due south of Sinclair Head, in waters known as the "Karori rip". The company claimed there is enough tidal movement in Cook Strait to generate 12 GW of power, more than one-and-a-half times New Zealand's current requirements. In practice, only some of this energy could be harnessed. As of October 2016, this turbine had not been built and the Neptune Power website is a placeholder with no further announcements.

On the other side of the strait, Energy Pacifica applied for resource consent to install up to 10 marine turbines, each able to produce up to 1.2 MW, near the Cook Strait entrance to Tory Channel. The company claimed that Tory Channel was an optimal site with a tidal current speed of 3.6 metres per second (12 ft/s) and the best combination of bathymetry and accessibility to the electricity network. However, despite being validated by computer modelling, no project was forthcoming.