tidal power

The project is applying to use part of the tidal mouth of the Kaipara Harbour in northern New Zealand to generate electricity using submerged marine turbines. Crest Energy plans to generate power for 250,000 NZ homes, or 200 MW, by harnessing about 2.5% of the power of the tidal flows in to and out of the Kaipara Harbour.

For a rapid understanding of the Crest Kaipara Energy Project watch their slide show.



The Kaipara Harbour is a source of pride and the spiritual heartland of the Ngati Whatua people of northern New Zealand. It is one of the largest harbours in the world covering 900 square kilometres with 3000 kilometres of shoreline. The Kaipara extends for 60 kilometres north to south: halfway along its length it has a five kilometre mouth to the Tasman Sea.

Tidal turbines follow the same principles as wind turbines: the faster the current, and the larger the blades, the more power is generated. There are perhaps a dozen companies constructing tidal turbines and others joining the industry.

Crest Energy will develop infrastructure to place 200 turbines in the mouth of the Kaipara. We will offer the turbine locations, with connections to the national electricity grid, to turbine manufacturers, electricity generators and investors. The project should generate over 3% of New Zealand's supply.

Tidal and wind power generation have many similarities and some differences :

• Sea water is 830 times denser than air which means that a tidal turbine can generate much more power for the same flow
• Tidal power works for over 16 hours a day in all seasons
• Tidal turbines are totally submerged and therefore invisible
• Tidal turbines are silent