Editing Cook Strait (section)

==Tidal power==
{{See also|Ocean power in New Zealand}}

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.<ref name="benign"/> Cook Strait has been identified as a potentially excellent source of tidal energy.<ref>Vennell, R., Major, R., Zyngfogel, R., Beamsley, B., Smeaton, M., Scheel, M. and Unwin, H., 2020. Rapid initial assessment of the number of turbines required for large-scale power generation by tidal currents. Renewable Energy, 162, pp.&nbsp;1890–1905. {{doi|10.1016/j.renene.2020.09.101}}.</ref>

In April 2008, Neptune Power was granted a resource consent to install a $10&nbsp;million experimental underwater [[Tidal stream generator|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 {{convert|80|m|ft}} of water, {{convert|4.5|km|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.<ref name="NZ_Herald_10504122">{{cite web |url=http://www.nzherald.co.nz/business/news/article.cfm?c_id=3&objectid=10504122 |title=Green light for Cook Strait energy generator trial |author=Doesburg, Anthony |date=15 April 2008 |work=[[The New Zealand Herald]] |access-date=26 September 2011}}</ref><ref>Renewable energy development: [http://renewableenergydev.com/red/tidal-energy-cook-strait/ Tidal Energy: Cook Strait] {{webarchive |url=https://web.archive.org/web/20090214122513/http://renewableenergydev.com/red/tidal-energy-cook-strait/ |date=14 February 2009 }}</ref><ref>[http://www.contrafedpublishing.co.nz/Energy+NZ/Harnessing+the+power+of+the+sea.html ''Harnessing the power of the sea'']. Energy NZ, vol.&nbsp;1, no.&nbsp;1, Winter 2007. {{webarchive|url=https://web.archive.org/web/20081014154810/http://www.contrafedpublishing.co.nz/Energy%2BNZ/Harnessing%2Bthe%2Bpower%2Bof%2Bthe%2Bsea.html |date=14 October 2008 }}.</ref><ref name="benign">[http://www.contrafedpublishing.co.nz/Energy+NZ/Benign+tides.html Benign tides]. {{Webarchive|url=https://web.archive.org/web/20100801055539/http://www.contrafedpublishing.co.nz/Energy+NZ/Benign+tides.html |date=1 August 2010 }}. Energy NZ, no.&nbsp;6, Spring 2008. Contrafed Publishing. Accessed 1 March 2009.</ref> In practice, only some of this energy could be harnessed.<ref>[http://www.radionz.co.nz/audio/national/ngts/2009/02/19/salty_water Radio New Zealand].</ref> 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 {{convert|3.6|m/s|ft/s}} and the best combination of [[bathymetry]] and accessibility to the electricity network.<ref name="benign"/> However, despite being validated by computer modelling,<ref>Plew, D. R. and Stevens, C. L., 2013. Numerical modelling of the effect of turbines on currents in a tidal channel–Tory Channel, New Zealand. Renewable Energy, 57, pp.&nbsp;269–282. {{doi|10.1016/j.renene.2013.02.001}}.</ref> no project was forthcoming.