122:
509:
1831:
483:
783:
1949:
1938:
1926:
811:
797:
30:
1914:
652:. It narrows to a width of 6 kilometres (3.7 mi), and is over 50 metres (160 ft) deep in parts. On average, Kaipara tides rise and fall 2.10 metres (6.9 ft). At high tide, nearly 1000 square kilometres are flooded. Spring tidal flows reach 9 km/h (5 knots) in the entrance channel and move 1,990 million cubic metres per tidal movement or 7,960 million cubic meters daily.
561:
high tide occurs five hours before it occurs at the Tasman Sea side. On one side is high tide and on the other is low tide. The difference in sea level can drive tidal currents up to 2.5 metres per second (5 knots) across Cook Strait as well as into the Tory
Channel. An unusual complication is that although there are two spring tides a month on the south side, the north side has only
765:, a Crown Research Institute, and Power Projects Limited, a privately owned Wellington-based company. The programme seeks to develop a wave energy device that generates electricity from both the kinetic and potential energy available in open ocean waves. In 2010 WET-NZ received resource consent for half-scale prototype testing at two test sites. The device is now called
742:
633:
621:
542:
526:
405:
492:
Since the construction of the
Manapouri power station, there has been about five MW of tide-determined generation. The tailrace tunnel exit by Dusky Sound debouches at sea level, and thus the effective head of the power station is affected by the level of the tide there. If the turbines are operated
457:
rather than circular. The effect of this is that the time between high tides changes a little from day to day. The Moon takes about 24.8 hours to orbit around the Earth, so it takes half this time, 12.4 hours, for the M2 tides to occur. The tides can be predicted far in advance, because the Moon and
362:
that also travels around the Earth. There are actually two high tides, because the Earth and Moon, as a system, both rotate about a common centre of mass. This centre is two-thirds out from the centre of the Earth, not at the centre of the Earth. The effect of the Earth spinning about this centre is
753:
On average, ocean waves in New
Zealand deliver about 25 kW to each metre of coastline. The west and south-west coasts have the country's most energetic waves. Even on windless days, swells that were generated in the Southern Ocean still arrive. Less wave energy arrives at the north-east coast,
565:
spring tide a month, as shown in the plot. A further consequence of these opposed tides is that there is almost zero tidal height change at the centre of the strait. Although the tidal surge should flow in one direction for six hours and then the reverse direction for six hours, a particular surge
465:
The actual tide pattern and timing is determined by the nature of the resonances in each ocean basin with the various frequencies of the gravitational influences, over many cycles. New
Zealand's situation (like Iceland's) is a small island in a large basin, and the peaks and troughs of the M2 tides
560:
has tidal flows amongst the strongest in the world, even though it has a smaller tidal range than most places in New
Zealand. This is because the main M2 lunar tide component which circulates anti-clockwise around New Zealand is out of phase at each end of the strait. On the Pacific Ocean side the
674:
Crest plans to place the turbines at least 30 metres deep along a ten kilometre stretch of the main channel. Historical charts show this stretch of the channel has changed little over 150 years. The output of the turbines will cycle twice daily with the predictable rise and fall of the tide. Each
587:
substation. The turbine is a pilot, and will be sited in slower tides for testing. Neptune hopes to generate power from the unit by 2010. The company has 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
566:
might last eight or ten hours with the reverse surge enfeebled. In especially boisterous weather conditions the reverse surge can be negated, and the flow can remain in the same direction through three surge periods and longer. This is indicated on marine charts for the region.
682:. It would have environmental benefits in offsetting annual carbon emissions from a thermal-based, gas turbine generator of 575,000 tonnes of carbon. The project is costed at about $ 600 million and to be economic would have to be scaled up rapidly to near full capacity.
466:
sweep continuously anticlockwise around New
Zealand. When it is high tide on the west coast, it is low tide on the east coast, and vice versa: the straightforward notion of tidal bulges aligned with the Moon is insufficient. These currents are most noticeable in
428:
A third influence occurs because the Moon orbits at an angle to the equator. This means that if one of the bulges travelling around the Earth is above the equator, then the other bulge is below the equator. It also follows that some places will have one daily
709:
into electricity using devices either fixed to the shore, the seabed or floating out at sea. Wave energy varies with time, depending on when and where the winds and storms that drive the waves occur. Tidal energy is more regular and predictable.
408:
412:
411:
407:
406:
413:
685:
However, while the
Department of Conservation has approved the project, and has made substantial environmental monitoring conditions part of the consent, the project also has objectors on the grounds of claimed influences on the local
339:
By world standards, New
Zealand's tides are, for the most part, moderate. The tide usually ranges between one and two metres. Tidal currents are usually around two kilometres per hour (one knot). Some exception are in and around
580:, it will be capable of producing one megawatt. It will be placed in eighty metres of water, 4.5 kilometres due south of Sinclair Head, in waters known as the “Karori rip”. Power from the turbine will be brought ashore at
410:
591:
On the other side of the strait, Energy
Pacifica has talked for some time about applying for resource consent to install up to ten marine turbines, each able to produce up to 1.2 MW, near the Cook Strait entrance to
366:
A second influence on the tides occurs because of gravitation from the Sun. Gravitation from the Sun has less influence than the Moon, because it is so much further from Earth. However, the Sun influences the
437:
near Antarctica every 24.84 hours. The height of this tide dwindles to almost zero in a cycle which takes 13.66 days. New Zealand's tides are semi-diurnal. The primary cause, the lunar tide, is labelled the
1301:
63:
was established in 2006 to "promote the uptake of marine energy in New Zealand". According to their 10 February 2008 newsletter, they have 59 members. However, the association doesn't list its members.
603:
The power generated by tidal marine turbines varies as the cube of the tidal speed. Because the tidal speed doubles, eight times more tidal power can be produced at spring tides than at neap tides.
493:
at a fixed flow aperture, the power produced is not constant but follows the tide, an effect that can be seen in the following graph. Note that the timing follows the tides around the clock,
1326:
569:
There are numerous computer model representations of the tidal flow through Cook Strait. While the tidal components are readily realizable, the residual flow is more difficult to model.
279:
1480:
549:
459:
1189:
Bowman, M.J., A.C. Kibblewhite, R. Murtagh, S.M. Chiswell and B.G. Sanderson (1983) Circulation and mixing in greater Cook Strait, New Zealand. Oceanologica Acta 6(4): 383-391
1127:
1448:
390:
New Zealand has a relatively small tidal range, usually less than two metres. However, some of the larger harbours on the west coast of the North Island, in particular the
1538:
310:
500:
The Opunake power station has its tailrace exiting to the beach but its operation is intermittent so if there is any tidal effect on generation there, it is unclear.
1296:
545:
82:
seem to offer the most promising sites for using underwater turbines. Two resource consents have been granted for pilot projects in Cook Strait itself and in the
1374:
1251:
1720:
576:
in the strait. The turbine has been designed in Britain and will be built in New Zealand at a cost $ 10 million. Fourteen metres in diameter and constructed of
409:
1620:
721:, a broad band of westerly winds that span the middle latitudes of the southern hemisphere. The roaring forties extend over most of the southern part of the
68:
880:
2008: Energy Pacifica applies 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
268:
60:
1983:
1490:
420:
This computer animation shows the peaks and troughs of the M2 tides sweeping anticlockwise around New Zealand. When it is high tide on one side of
533:
1323:
512:
Tidal patterns in Cook Strait. The south part (Nelson) has two spring tides per month, versus only one on the north side (Wellington and Napier).
102:
with tidal flows up to 100,000 cubic metres a second. These tidal volumes are 12 times greater than the flows in the largest New Zealand rivers.
1862:
1770:
303:
1151:
1696:
1655:
1830:
1230:
328:
Tidal power is generated by capturing some of the energy in the tides as they cycle forth and back, twice each day. Tidal devices can be
1003:
121:
1087:
284:
1616:
401:
on the tides, though only some will be significant at a given location. The gravitation of the Moon and Sun are the most important.
296:
176:
1167:
1455:
1421:
1068:
71:
is allocating $ 2 million each year from a Marine Energy Deployment Fund, set up to encourage the utilisation of this resource.
1973:
1888:
1815:
955:
920:
910:
215:
761:
Wave Energy Technology - New Zealand (WET-NZ) is a Government-funded research and development collaboration programme between
1978:
678:
The peak level of generation for the combined turbines is about 200 MW. This exceeds the projected peak electricity needs of
915:
845:
59:
projects are currently under development. However, not a lot of public information is available about these projects. The
1847:
717:
dominate in the north, enlivened by an occasional cyclone from the tropics. The rest of the country is dominated by the
358:
of the Moon. About once a day the Moon rotates around the Earth, attracting as it travels the bulge of water called the
86:, and consent is being sought for a project sites at the entrance to the Kaipara. Other potential locations include the
729:. These winds produce some of the stormiest seas in the world, with maximum wave heights regularly exceeding 4 metres.
453:
A fourth influence occurs because the orbit of the Moon around the Earth and the orbit of the Earth around the Sun are
1878:
1800:
1795:
1368:
1245:
762:
664:
1686:
758:
is proportional to the square of its height, so a two-metre wave contains four times the energy of a one-metre wave.
383:. When the Sun is at right angles to the Moon, the effects are partially cancelled, producing the small tides called
474:, just off the greater Cook Strait, where, despite the low tidal range, tidal streams can reach nearly eight knots.
1763:
1391:
1200:
348:. Headlands and constrictions like these focus the currents, giving energy levels reaching 750 W per square metre.
572:
In April 2008, a resource consent was granted to Neptune Power for the installation of an experimental underwater
1512:
950:
900:
363:
that it behaves as a centrifuge, resulting in a second high tide bulge in the ocean most distant from the Moon.
1625:
433:
tide, while other places will have semi-diurnal tides twice a day. For example, there is a diurnal tide in the
754:
because it is sheltered from the south-west waves (click the link on the right for a diagram). The amount of
424:
it is low tide on the other side. For this reason, Cook Strait can experience exceptionally fast tidal flows.
1930:
1805:
827:
816:
766:
471:
95:
33:
671:
moving in and out every day near the harbour mouth to produce electricity for approximately 250,000 homes.
1952:
1857:
1820:
1587:
1555:
1396:
1205:
980:
573:
245:
745:
1893:
1756:
1435:
1267:
675:
turbine will have a maximum output of 1.2 MW, and is expected to generate 0.75 MW averaged over time.
1883:
905:
205:
151:
1148:
235:
146:
851:
2008: SeaGen, the world's first commercial scale tidal stream energy generator, goes on stream in
1665:
1650:
1178:
788:
706:
355:
161:
1708:
529:
482:
344:, where tidal currents can be much stronger, and at the entrance to some harbours, particularly
1227:
691:
156:
1010:
859:
852:
755:
679:
656:
171:
166:
113:
91:
1690:
1677:
1659:
1378:
1330:
1305:
1255:
1234:
1155:
895:
867:
718:
645:
391:
345:
87:
79:
1742:
873:
2008: Neptune Power given resource consent to build a pilot turbine off Sinclair Head in
17:
1324:
Pathway to energy generation from marine tidal currents in New Zealand's Kaipara Harbour
833:
2003: Seaflow, the world's first underwater turbine prototype, goes on stream off north
1044:
726:
581:
600:
and access to the electricity network. No application had been lodged by March 2011.
1967:
1942:
1918:
1898:
1852:
1779:
1725:
925:
802:
379:), their tidal effects combine, producing the particularly high and low tides called
333:
220:
210:
1643:
Squeezing information from an elusive ocean: surface currents from satellite imagery
636:
624:
1937:
1517:
881:
796:
593:
577:
225:
83:
44:
29:
1641:
1632:
1925:
1839:
1730:
1592:
1560:
930:
874:
863:
810:
660:
557:
368:
341:
240:
230:
198:
188:
99:
75:
56:
40:
508:
1787:
940:
778:
722:
714:
702:
694:
were concluded in 2010, with a favourable decision released in February 2011.
649:
597:
584:
398:
257:
252:
193:
183:
52:
1713:
1670:
975:
596:. They claim Tory Channel has tidal flows of 3.6 metres per second with good
336:), used to hold the tide back, or turbines anchored within the tidal stream.
1913:
1485:
1115:
945:
935:
841:
687:
384:
376:
359:
1683:
1283:
1130:
Prepared for the Energy Efficiency and Conservation Authority, 18 May 2005
1128:
Marine Energy: Summary of Current Developments and Outlook for New Zealand
434:
372:
588:
requirements. In practice, only some of this energy could be harnessed.
454:
141:
131:
1356:
467:
136:
1640:
Bowen M, Richardson K, Pinkerton M, Korpela A and Uddstrom M (2004)
1582:
1550:
830:
project goes online at La Rance, France, with a capacity of 240 MW.
1513:"Making waves: UK firm harnesses power of the sea ... in Portugal"
1449:"Marine Current Turbines: progress with tidal turbine development"
1426:
Te Ara: The Encyclopedia of New Zealand, updated 21 September 2007
1073:
Te Ara: The Encyclopedia of New Zealand, updated 21 September 2007
834:
668:
507:
481:
403:
371:. When the Sun, Earth and Moon are aligned in a straight line (at
1392:"Anthony Doesburg: Harnessing tidal power not all smooth sailing"
1100:
470:
such as Cook Strait and in Foveaux Strait. A notable example is
1748:
648:, one of the largest harbours in the world, is a channel to the
380:
351:
329:
48:
1752:
1343:
1736:
1628:
Prepared for the Energy Efficiency and Conservation Authority.
430:
394:, experience significant currents as the tides rise and fall.
530:
Cook Strait currents before and after high tide at Wellington
1033:
462:(NIWA) run a tidal computer model specific to New Zealand.
418:
Global surface elevation of the M2 ocean tide (NASA)
1085:
Stevens, Craig; Smith, Murray and Gorman, Richard (2005)
47:
resources but does not yet generate any power from them.
1726:
Electricity Generation from Tidal Power In New Zealand
1201:"Green light for Cook Strait energy generator trial"
460:
National Institute of Water and Atmospheric Research
1871:
1838:
1786:
1158:
Energy NZ No.6, Spring 2008. Contrafed Publishing.
734:
613:
518:
855:, Northern Ireland with a peak capacity of 1.2 MW.
497:the usual twenty-four cycle of electricity usage.
655:In 2011, Crest Energy, a power company, received
1318:
1316:
1314:
1298:Kaipara Harbour Environmental Information Review
1279:
1277:
1662:The Gamma Series, Royal Society of New Zealand.
1637:Water & Atmosphere, Vol.12, No.4 - December
1481:"Wave power scientist enthused by green energy"
858:2008: Crest Energy Kaipara Limited applies for
1697:Harnessing the Tides: Marine Power Update 2009
1436:Implementing Agreement on Ocean Energy Systems
1416:
1414:
713:Two wind zones affect New Zealand. South-east
1764:
1063:
1061:
1059:
1057:
1055:
1053:
304:
8:
1621:Energy Efficiency and Conservation Authority
1045:Energy Efficiency and Conservation Authority
458:Earth have orbits that are predictable. The
69:Energy Efficiency and Conservation Authority
1684:NZ: Chance to turn the tide of power supply
848:devices and has a peak capacity of 2.25 MW.
1771:
1757:
1749:
1631:Rickard, Graham and Hadfield, Mark (2004)
1322:Bellve, AR; Austin, G and Woods, B (2007)
1295:Haggit T, Mead S, and Bellingham M (2008)
1034:Aotearoa Wave and Tidal Energy Association
311:
297:
269:Nuclear power proposed as renewable energy
104:
61:Aotearoa Wave and Tidal Energy Association
36:has the fastest tidal flows in New Zealand
1144:
1142:
1140:
1138:
1136:
1088:Ocean bounty: energy from waves and tides
1081:
1079:
690:and charter fishing. Appeals before the
98:. The harbours produce currents up to 6
28:
1179:Lunar tides in Cook Strait, New Zealand
967:
534:Te Ara: The Encyclopedia of New Zealand
112:
1863:Development of tidal stream generators
1739:(Wave Energy Technology - New Zealand)
1551:"DOC considering Kaipara turbine plan"
1420:Stevens, Craig and Chiswell, Stephen.
1390:Doesburg, Anthony (1 September 2008).
1067:Stevens, Craig and Chiswell, Stephen.
976:"Tidal power rides wave of popularity"
746:Average wave height around New Zealand
731:
610:
515:
1091:Water & Atmosphere, Vol.13, No.4.
7:
1672:Tidal power rides wave of popularity
1646:Water & Atmosphere, Vol.12, No.4
1372:Energy NZ, Vol 1, No 1, Winter 2007.
546:Underwater topography of Cook Strait
1249:Energy NZ, Vol 1, No 1, Winter 2007
1199:Doesburg, Anthony (15 April 2008).
844:goes on line in Portugal. It uses
840:2008: The world's first commercial
705:involves converting the energy in
667:, which would use the substantial
67:From 2008 to 2011, the government
25:
1617:Marine energy in NZ report - 2008
1308:ARC Technical Publication TP 354.
1948:
1947:
1936:
1924:
1912:
1829:
1284:Photo gallery of Kaipere Harbour
870:, with a peak capacity of 200MW.
809:
795:
781:
740:
659:to install about 200 underwater
631:
619:
540:
524:
421:
120:
1984:Renewable energy in New Zealand
1889:Ocean thermal energy conversion
1423:Ocean currents and tides: Waves
1370:Harnessing the power of the sea
1247:Harnessing the power of the sea
1101:Ocean Tides and Magnetic Fields
1070:Ocean currents and tides: Tides
956:Renewable energy in New Zealand
921:Renewable energy in New Zealand
911:Ocean thermal energy conversion
837:with a peak capacity of 300 KW.
769:and is being tested in Hawaii.
397:Altogether there are sixty-two
280:Topics by country and territory
1721:Video: Chasing currents (NIWA)
1511:Alok Jha (25 September 2008).
1226:Renewable energy development:
51:reported in 2007 that over 20
1:
1666:Tidal Power | Kaipara Harbour
1539:Tidal power in the UK: SeaGen
1116:Tide Forecaster (New Zealand)
916:Pelamis Wave Energy Converter
399:recognised natural influences
354:are controlled mainly by the
1848:List of tidal power stations
1715:A Beautiful Source of Energy
1583:"Tidal power trial approved"
1004:"AWATEA February newsletter"
625:Kaipara Harbour main channel
446:stands for the Moon and the
1931:Renewable energy portal
1879:List of offshore wind farms
1801:List of wave power projects
1796:List of wave power stations
1634:Forecasting ocean "weather"
763:Industrial Research Limited
665:Kaipara Tidal Power Station
637:Proposed cable and turbines
285:Marketing and policy trends
2000:
487:Generation and tide height
1907:
1827:
1228:Tidal Energy: Cook Strait
1104:NASA Visualization Studio
951:Wind power in New Zealand
901:Intermittent power source
739:
630:
618:
539:
523:
18:Wave power in New Zealand
1733:– J Floor Anthoni, 2000.
1709:Ocean Energy Review 2008
1626:Marine energy fact sheet
1489:. London. Archived from
450:stands for twice a day.
332:or dam like structures (
1333:University of Auckland.
926:Salinity gradient power
817:Renewable energy portal
1974:Tidal power by country
1858:Tidal stream generator
1743:Power Projects Limited
1652:Harnessing the Oceans?
1649:Stevens, Craig (2007)
1588:Television New Zealand
1556:Television New Zealand
1397:The New Zealand Herald
1206:The New Zealand Herald
513:
489:
425:
246:Tidal stream generator
37:
1979:Wave power by country
1894:Offshore construction
1693:Anthony Bellve, 2005.
1438:October 2010 Bulletin
866:near the entrance of
511:
485:
416:
32:
1884:Marine current power
1168:Chart of Cook Strait
906:Marine current power
574:tidal stream turbine
206:Marine current power
152:Crosswind kite power
1731:Oceanography: waves
1106:, 30 December 2016.
828:first tidal barrage
707:ocean surface waves
236:Sustainable biofuel
147:Carbon-neutral fuel
108:Part of a series on
1689:2012-03-10 at the
1658:2008-10-18 at the
1377:2011-07-24 at the
1329:2008-10-14 at the
1304:2012-02-18 at the
1254:2011-07-24 at the
1233:2009-02-14 at the
1154:2010-08-01 at the
826:1966: The world's
789:New Zealand portal
514:
490:
426:
356:gravitational pull
162:Geothermal heating
38:
1961:
1960:
1943:Oceans portal
1919:Energy portal
1619:Prepared for the
984:. 2 December 2007
751:
750:
692:Environment Court
642:
641:
555:
554:
414:
321:
320:
157:Geothermal energy
92:Hokianga Harbours
16:(Redirected from
1991:
1951:
1950:
1941:
1940:
1929:
1928:
1917:
1916:
1833:
1773:
1766:
1759:
1750:
1605:
1604:
1602:
1600:
1579:
1573:
1572:
1570:
1568:
1547:
1541:
1536:
1530:
1529:
1527:
1526:
1508:
1502:
1501:
1499:
1498:
1476:
1470:
1469:
1467:
1466:
1460:
1454:. Archived from
1453:
1445:
1439:
1433:
1427:
1418:
1409:
1408:
1406:
1404:
1387:
1381:
1366:
1360:
1354:
1348:
1347:
1340:
1334:
1320:
1309:
1293:
1287:
1281:
1272:
1271:
1264:
1258:
1243:
1237:
1224:
1218:
1217:
1215:
1213:
1196:
1190:
1187:
1181:
1176:
1170:
1165:
1159:
1146:
1131:
1125:
1119:
1113:
1107:
1098:
1092:
1083:
1074:
1065:
1048:
1042:
1036:
1031:
1025:
1024:
1022:
1021:
1015:
1009:. Archived from
1008:
1000:
994:
993:
991:
989:
972:
860:resource consent
853:Strangford Lough
819:
814:
813:
805:
800:
799:
791:
786:
785:
784:
756:energy in a wave
744:
743:
732:
657:resource consent
644:The entrance to
635:
634:
623:
622:
611:
544:
543:
528:
527:
516:
415:
313:
306:
299:
177:Run-of-the-river
172:Hydroelectricity
167:Geothermal power
124:
114:Renewable energy
105:
21:
1999:
1998:
1994:
1993:
1992:
1990:
1989:
1988:
1964:
1963:
1962:
1957:
1935:
1923:
1911:
1903:
1867:
1834:
1825:
1782:
1777:
1705:
1691:Wayback Machine
1660:Wayback Machine
1613:
1611:Further reading
1608:
1598:
1596:
1581:
1580:
1576:
1566:
1564:
1549:
1548:
1544:
1537:
1533:
1524:
1522:
1510:
1509:
1505:
1496:
1494:
1478:
1477:
1473:
1464:
1462:
1458:
1451:
1447:
1446:
1442:
1434:
1430:
1419:
1412:
1402:
1400:
1389:
1388:
1384:
1379:Wayback Machine
1367:
1363:
1355:
1351:
1342:
1341:
1337:
1331:Wayback Machine
1321:
1312:
1306:Wayback Machine
1294:
1290:
1286:– Crest Energy.
1282:
1275:
1266:
1265:
1261:
1256:Wayback Machine
1244:
1240:
1235:Wayback Machine
1225:
1221:
1211:
1209:
1198:
1197:
1193:
1188:
1184:
1177:
1173:
1166:
1162:
1156:Wayback Machine
1147:
1134:
1126:
1122:
1114:
1110:
1099:
1095:
1084:
1077:
1066:
1051:
1047:- Marine Energy
1043:
1039:
1032:
1028:
1019:
1017:
1013:
1006:
1002:
1001:
997:
987:
985:
974:
973:
969:
965:
960:
896:Capacity factor
891:
868:Kaipara Harbour
864:marine turbines
823:
822:
815:
808:
801:
794:
787:
782:
780:
775:
741:
719:roaring forties
700:
646:Kaipara Harbour
632:
620:
614:External images
609:
607:Kaipara Harbour
541:
525:
519:External images
506:
488:
480:
419:
404:
346:Kaipara Harbour
326:
317:
80:Kaipara Harbour
23:
22:
15:
12:
11:
5:
1997:
1995:
1987:
1986:
1981:
1976:
1966:
1965:
1959:
1958:
1956:
1955:
1945:
1933:
1921:
1908:
1905:
1904:
1902:
1901:
1896:
1891:
1886:
1881:
1875:
1873:
1869:
1868:
1866:
1865:
1860:
1855:
1850:
1844:
1842:
1836:
1835:
1828:
1826:
1824:
1823:
1818:
1813:
1808:
1803:
1798:
1792:
1790:
1784:
1783:
1778:
1776:
1775:
1768:
1761:
1753:
1747:
1746:
1740:
1734:
1728:
1723:
1718:
1711:
1704:
1703:External links
1701:
1700:
1699:
1694:
1681:
1678:Why Marine>
1675:
1668:
1663:
1647:
1638:
1629:
1623:
1612:
1609:
1607:
1606:
1574:
1542:
1531:
1503:
1471:
1440:
1428:
1410:
1382:
1361:
1349:
1344:"Crest Energy"
1335:
1310:
1288:
1273:
1259:
1238:
1219:
1191:
1182:
1171:
1160:
1132:
1120:
1108:
1093:
1075:
1049:
1037:
1026:
995:
966:
964:
961:
959:
958:
953:
948:
943:
938:
933:
928:
923:
918:
913:
908:
903:
898:
892:
890:
887:
886:
885:
878:
871:
856:
849:
838:
831:
821:
820:
806:
792:
777:
776:
774:
771:
749:
748:
737:
736:
735:External image
727:Southern Ocean
699:
696:
661:tidal turbines
640:
639:
628:
627:
616:
615:
608:
605:
553:
552:
537:
536:
521:
520:
505:
502:
486:
479:
476:
417:
325:
322:
319:
318:
316:
315:
308:
301:
293:
290:
289:
288:
287:
282:
274:
273:
272:
271:
263:
262:
261:
260:
255:
250:
249:
248:
238:
233:
228:
223:
218:
213:
208:
203:
202:
201:
196:
191:
181:
180:
179:
169:
164:
159:
154:
149:
144:
139:
134:
126:
125:
117:
116:
110:
109:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1996:
1985:
1982:
1980:
1977:
1975:
1972:
1971:
1969:
1954:
1946:
1944:
1939:
1934:
1932:
1927:
1922:
1920:
1915:
1910:
1909:
1906:
1900:
1899:Osmotic power
1897:
1895:
1892:
1890:
1887:
1885:
1882:
1880:
1877:
1876:
1874:
1870:
1864:
1861:
1859:
1856:
1854:
1853:Tidal barrage
1851:
1849:
1846:
1845:
1843:
1841:
1837:
1832:
1822:
1819:
1817:
1816:United States
1814:
1812:
1809:
1807:
1804:
1802:
1799:
1797:
1794:
1793:
1791:
1789:
1785:
1781:
1780:Marine energy
1774:
1769:
1767:
1762:
1760:
1755:
1754:
1751:
1744:
1741:
1738:
1735:
1732:
1729:
1727:
1724:
1722:
1719:
1717:
1716:
1712:
1710:
1707:
1706:
1702:
1698:
1695:
1692:
1688:
1685:
1682:
1679:
1676:
1674:
1673:
1669:
1667:
1664:
1661:
1657:
1654:
1653:
1648:
1645:
1644:
1639:
1636:
1635:
1630:
1627:
1624:
1622:
1618:
1615:
1614:
1610:
1594:
1590:
1589:
1584:
1578:
1575:
1563:. 30 May 2008
1562:
1558:
1557:
1552:
1546:
1543:
1540:
1535:
1532:
1520:
1519:
1514:
1507:
1504:
1493:on 2012-12-23
1492:
1488:
1487:
1482:
1475:
1472:
1461:on 2012-02-20
1457:
1450:
1444:
1441:
1437:
1432:
1429:
1425:
1424:
1417:
1415:
1411:
1399:
1398:
1393:
1386:
1383:
1380:
1376:
1373:
1371:
1365:
1362:
1358:
1353:
1350:
1345:
1339:
1336:
1332:
1328:
1325:
1319:
1317:
1315:
1311:
1307:
1303:
1300:
1299:
1292:
1289:
1285:
1280:
1278:
1274:
1269:
1263:
1260:
1257:
1253:
1250:
1248:
1242:
1239:
1236:
1232:
1229:
1223:
1220:
1208:
1207:
1202:
1195:
1192:
1186:
1183:
1180:
1175:
1172:
1169:
1164:
1161:
1157:
1153:
1150:
1145:
1143:
1141:
1139:
1137:
1133:
1129:
1124:
1121:
1117:
1112:
1109:
1105:
1102:
1097:
1094:
1090:
1089:
1082:
1080:
1076:
1072:
1071:
1064:
1062:
1060:
1058:
1056:
1054:
1050:
1046:
1041:
1038:
1035:
1030:
1027:
1016:on 2008-10-14
1012:
1005:
999:
996:
983:
982:
977:
971:
968:
962:
957:
954:
952:
949:
947:
944:
942:
939:
937:
934:
932:
929:
927:
924:
922:
919:
917:
914:
912:
909:
907:
904:
902:
899:
897:
894:
893:
888:
883:
879:
876:
872:
869:
865:
861:
857:
854:
850:
847:
843:
839:
836:
832:
829:
825:
824:
818:
812:
807:
804:
803:Oceans portal
798:
793:
790:
779:
772:
770:
768:
764:
759:
757:
747:
738:
733:
730:
728:
724:
720:
716:
711:
708:
704:
697:
695:
693:
689:
683:
681:
676:
672:
670:
666:
662:
658:
653:
651:
647:
638:
629:
626:
617:
612:
606:
604:
601:
599:
595:
589:
586:
583:
579:
575:
570:
567:
564:
559:
551:
547:
538:
535:
531:
522:
517:
510:
503:
501:
498:
496:
484:
477:
475:
473:
469:
463:
461:
456:
451:
449:
445:
441:
436:
432:
423:
402:
400:
395:
393:
388:
386:
382:
378:
374:
370:
364:
361:
357:
353:
349:
347:
343:
337:
335:
331:
323:
314:
309:
307:
302:
300:
295:
294:
292:
291:
286:
283:
281:
278:
277:
276:
275:
270:
267:
266:
265:
264:
259:
256:
254:
251:
247:
244:
243:
242:
239:
237:
234:
232:
229:
227:
224:
222:
221:Osmotic power
219:
217:
216:Ocean thermal
214:
212:
211:Marine energy
209:
207:
204:
200:
197:
195:
192:
190:
187:
186:
185:
182:
178:
175:
174:
173:
170:
168:
165:
163:
160:
158:
155:
153:
150:
148:
145:
143:
140:
138:
135:
133:
130:
129:
128:
127:
123:
119:
118:
115:
111:
107:
106:
103:
101:
97:
93:
89:
85:
81:
77:
72:
70:
65:
62:
58:
54:
50:
46:
42:
35:
31:
27:
19:
1810:
1745:Publications
1714:
1671:
1651:
1642:
1633:
1597:. Retrieved
1595:. 2 May 2008
1586:
1577:
1565:. Retrieved
1554:
1545:
1534:
1523:. Retrieved
1518:The Guardian
1516:
1506:
1495:. Retrieved
1491:the original
1484:
1479:Emily Ford.
1474:
1463:. Retrieved
1456:the original
1443:
1431:
1422:
1401:. Retrieved
1395:
1385:
1369:
1364:
1359:Crest Energy
1352:
1338:
1297:
1291:
1262:
1246:
1241:
1222:
1210:. Retrieved
1204:
1194:
1185:
1174:
1163:
1149:Benign tides
1123:
1111:
1103:
1096:
1086:
1069:
1040:
1029:
1018:. Retrieved
1011:the original
998:
986:. Retrieved
979:
970:
882:Tory Channel
862:to sink 200
760:
752:
712:
701:
684:
677:
673:
654:
643:
602:
594:Tory Channel
590:
578:carbon fibre
571:
568:
562:
556:
499:
494:
491:
464:
452:
447:
443:
439:
427:
396:
389:
381:spring tides
365:
350:
338:
327:
226:Solar energy
84:Tory Channel
74:The greater
73:
66:
45:ocean energy
39:
26:
1840:Tidal power
1811:New Zealand
1593:Newstalk ZB
1561:Newstalk ZB
931:Tidal power
875:Cook Strait
715:trade winds
669:tidal flows
558:Cook Strait
504:Cook Strait
472:French Pass
422:Cook Strait
369:tidal range
342:Cook Strait
324:Tidal power
241:Tidal power
231:Solar power
199:Small hydro
189:Micro hydro
96:French Pass
76:Cook Strait
57:tidal power
41:New Zealand
34:French Pass
1968:Categories
1788:Wave power
1599:1 November
1567:1 November
1525:2008-10-09
1497:2008-10-15
1465:2009-03-06
1403:1 November
1212:1 November
1020:2009-03-02
988:1 November
963:References
941:Wave power
723:Tasman Sea
703:Wave power
698:Wave power
688:ecosystems
650:Tasman Sea
598:bathymetry
585:Island Bay
455:elliptical
385:neap tides
258:Wind power
253:Wave power
194:Pico hydro
184:Hydropower
43:has large
1806:Australia
1486:The Times
946:Wind wave
936:Wave farm
842:wave farm
680:Northland
478:Manapouri
377:full moon
360:high tide
1953:Category
1821:Scotland
1687:Archived
1656:Archived
1521:. London
1375:Archived
1327:Archived
1302:Archived
1252:Archived
1231:Archived
1152:Archived
981:One News
889:See also
773:Timeline
725:and the
663:for the
582:Vector's
435:Ross Sea
334:barrages
846:Pelamis
468:straits
431:diurnal
392:Kaipara
142:Biomass
132:Biofuel
94:, and
88:Manukau
1737:WET-NZ
1680:– BWEA
1118:– NIWA
442:. The
137:Biogas
1872:Other
1459:(PDF)
1452:(PDF)
1268:"RNZ"
1014:(PDF)
1007:(PDF)
835:Devon
767:Azura
352:Tides
100:knots
1601:2011
1569:2011
1405:2011
1214:2011
990:2011
550:NIWA
375:and
330:weir
90:and
78:and
55:and
53:wave
49:TVNZ
1357:FAQ
563:one
495:not
373:new
1970::
1591:.
1585:.
1559:.
1553:.
1515:.
1483:.
1413:^
1394:.
1313:^
1276:^
1203:.
1135:^
1078:^
1052:^
978:.
548:–
532:–
440:M2
387:.
1772:e
1765:t
1758:v
1603:.
1571:.
1528:.
1500:.
1468:.
1407:.
1346:.
1270:.
1216:.
1023:.
992:.
884:.
877:.
448:2
444:M
312:e
305:t
298:v
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
