• Resource consent for 1MW turbine.
• Aim to start trial by early 2009.
• Impact on marine mammals critical.

Neptune Power has gained resource consents for a tidal generation turbine off Sinclair Head in Cook Strait, which it hopes will lay the groundwork for a tidal energy industry in NZ. The company is planning to trial a 1MW turbine about 5km offshore, hopefully from early 2009. Director David Beach is delighted with the speed with which the Greater Wellington Regional Council has processed the consent application, with approval coming in less than six months. Beach says the company has come to an agreement with commercial fishermen in the area, and also with the Department of Conservation, which is worried about the impact of the turbine on some whale species and other marine mammals. In fact, a key feature of the trial will be studying the impact of tidal turbines on marine mammals in Cook Strait, which Beach notes is a “big unknown” at the moment, as there has been little research done into marine mammals in the Strait.

He adds the feasibility of a commercial tidal generation project could hinge ultimately on the impact on marine mammals. Beach notes dolphins and killer whales all have a well-developed acoustic system, which warns them of obstacles in the water, so they shouldn’t be a problem. But other species of whale and possibly other sea mammals could be an issue.

Neptune is looking at a UK-made tidal turbine for the trial but Beach won’t disclose details yet. The turbines, understood to cost about $10m each, are now being tested off the Orkney Islands, which has become the world’s leading area for trialling tidal turbine technology. Beach says once initial testing has been completed in the UK, Neptune hopes to build the final turbine in NZ. This could take place later this year or early in 2009.

Neptune’s initial resource consent is for 10 years, which Beach says allows more than enough time for the trial. Neptune hopes to make a decision on tidal energy’s commercial viability within two years of putting the trial generator in the water. Beach says Neptune has been talking to Meridian Energy and other power generators about the possibility of a joint venture in tidal energy. So far they have shown little interest, due to the risky nature of such a venture.

But Neptune is confident it can attract the necessary investment from within NZ to develop a commercial tidal generation project, without the need for any of the existing power generation companies to come on board. Beach says the ideal would be to build 30 turbines as an initial venture. Current turbines are 1MW each, so it would generate a relatively modest 30MW. But new tidal turbine technology being developed in the UK should see 5MW units available in a few years. Ultimately, Neptune believes there could be potential for several thousand megawatts of tidal energy in Cook Strait.

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