By K.Steiner-Dicks on Feb 26, 2014

The Turnagain Arm of Cook Inlet, located at Anchorage, Alaska, has the second

highest tidal energy potential in the world. This site fulfils the two key conditions for success:

Having high tides and secondly being near a key market, Anchorage, home to half the Alaskan population.

In a 2012 presentation published by Alaska power company, Chugach Electric, Turnagain Arm Tidal Energy Corporation. (TATEC) proposed to build a 240MW tidal power plant with a potential for expansion to 1,200MW that will be market-ready by 2018.

In February 2013 the tidal power company filed an application for a preliminary permit, pursuant to section 4(f) of the Federal Power Act (FPA), proposing to study the feasibility of the Turnagain Arm Tidal Electric Generation Project to be located on the Turnagain Arm of Cook Inlet and adjacent lands of the Kenai Peninsula Borough and the Municipality of Anchorage, Alaska.

The sole purpose of a preliminary permit, if issued, was to grant the permit holder priority to file a license application during the permit term. However, a preliminary permit does not authorise the permit holder to perform any land-disturbing activities or otherwise enter upon lands or waters owned by others without the owners' express permission.

The proposed project would consist of an 8-mile-long tidal fence situated between Fire Island near Anchorage and Point Possession in the Kenai Peninsula Borough, and consisting of 24, 10-megawatt (MW) Davis turbines with tidal-to-electrical energy generating units for a total installed capacity of 240 MW.

As part of the development would be one control building/substation onshore near Anchorage and one near Point Possession connected to an 18-mile-long, 230-kilovolt (kV) submerged transmission line connecting the tidal fence to the existing Chugach Electric Association substation at Point Woronzof in Anchorage and a new substation at Point Possession.

The aboveground works would include a 28-mile-long, 230-kV aboveground transmission line running parallel to an existing Homer Electric Association (HEA) transmission line corridor and extending from Point Possession to the existing HEA Nikiski substation; and also appurtenant facilities. The proposed project would have an estimated average annual generation of 1,271,950 megawatt-hours.

At the time of the 2012 utility presentation, the proposed project would cost just over $880m with current peak electrical power demand in the Anchorage area in the region of 803MW. With operations and maintenance of such a facility at about 1% of the construction cost, the first phase debt could be repaid within six years once operating, and within one year on the Phase II expansion, according to the project presentation on the Chugach Electric web site.

Reportedly, the technology to be used is proven yet patent pending by TATEC’s The LaRance Tidal Power Plant in France, which has been in operation since 1966, and produces 240MW electricity, which is in turn, sold to its local residents at 1.2 cents/kilowatt-hour.