The project has an area of approximately 1691 ha and is located within waters with current velocities in excess of 2.0 m/s. This would allow for 456 turbines at this location.
Clarence Strait is a narrow body of water in the vicinity of the Vernon Islands, approximately 50 km north of Darwin, Northern Territory and south of the Tiwi Islands. It links the Beagle Gulf in the west with the Van Diemen Gulf in the east. The Strait is situated within the Timor Sea with the Vernon Islands located within the Strait. The islands consist of North West Vernon, South West Vernon and East Vernon Island and Knight Reef. These islands form three channels that wind through the area. These are generally 100 m to over 1 km wide and have complex bathymetry.
The proposed Clarence Strait site was identified as the site with the greatest tide velocities in the greater Darwin vicinity. Clarence Strait experiences tidal variations of up to 8 m, producing extended periods of suitable tidal currents. The water depth in Clarence Strait varies from 25 to 50 m based on Australia Hydrographic Charts of the area (adequate depth for TEG) and the velocity ranges from 2.00 to 2.75 m/s.
Established in 2007, Tenax Energy identified a significant gap in Australia’s renewable energy sector. Recognising that Australia is in a unique position with thousands of kilometres of coastline, Tenax Energy set about researching how to maximise this natural resource to generate green energy and reduce our greenhouse gas emissions.
Preliminary details outlining the Clarence Strait project were completed in December of 2008. As of July 8th, 2009, the project is currently subject to review under the Environmental Assessment Act (EA Act). During this period, there will be the opportunity for public to comment at the various stages in the assessment process. These opportunities will be listed on the items for public comment page and will be advertised in the local paper as they arise. No devices are yet in the water.
The first stage of the Clarence Strait project involves the establishment of a global centre of excellence in tropical tidal energy. This is supported by MOUs with the Research Institute for the Environment and Livelihoods at Charles Darwin University and with the European Marine Energy Centre in Scotland, and will form an integral part of the initial 10MW or pilot phase of the project. It will accelerate the development of the Clarence Strait project and at the same time contribute to the understanding of the technologies by regulatory bodies in tropical zones and in the Asia Pacific region.
A formal Notice of Intent (NOI) for assessment under the Environmental Assessment Act of 1982 was prepared by URS Australia Pty Ltd (URS) on behalf of the proponent Tenax Energy Pty Ltd (Tenax Energy). Although Northern Territory legislation applies to the project area, there is also Commonwealth legislation that will apply to the project as well, notably the EPBC Act.
The proponent referred this proposal to the Australian Government under the Environment Protection and Biodiversity Conservation (EPBC) Act. On 28 January 2009, the project was deemed to be a controlled action and will be assessed under the bilateral agreement between the NT and Australian Governments. The controlling provisions are:
- Listed threatened species and communities (sections 18 and 18A);
- Listed migratory species (sections 20 and 20A); and
- Commonwealth marine areas (section 23 & 24A).
Tidal energy generation is a relatively new technology and as there are no previous examples of such a project in the proposed area, consideration will need to be given to site and species-specific monitoring programs for the identification and management of actual and potential environmental impacts. In addition, relevant technical data from environmental impact assessment studies for related technologies should be provided to assist in the assessment of impacts.