Alaska company pursues 240-MW tidal energy project at FERC

The Federal Energy Regulatory Commission said in a July 18 notice that Turnagain Arm Tidal Energy Corp. has applied for a preliminary permit on a 240-MW tidal hydroelectric project in Alaska.

On Feb. 1, the Turnagain Arm Tidal Energy filed the preliminary permit application, 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 purpose of a preliminary permit, if issued, is to grant the permit holder priority to file a license application during the 36-month permit term. A license application would then be needed at FERC if the decision is to move forward.

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-MW Davis turbines with tidal-to-electrical energy generating units for a total installed capacity of 240 MW;
  • one control building/substation onshore near Anchorage and one near Point Possession;
  • an 18-mile-long, 230-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; and
  • 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.

The proposed project would have an estimated average annual generation of 1,271,950 megawatt-hours.

Dominic Lee is the President and CEO of Turnagain Arm Tidal Energy, with an address in Anchorage, Alaska.

Company says project could replace aging fossil-fired capacity in the region

The southern portion of the Railbelt region – the Mat-Su Valley, Anchorage, and Kenai Peninsula – are highly dependent on natural gas as the source of electricity and heat, and the majority of the generation is combustion turbine generation, said the application. The Cook Inlet gas basin still yields natural gas for power generation and space heating, but known reserves are now falling and dropping field operating pressure are causing concern that the region may not be able to depend on lower Cook Inlet for adequate gas supplies in the future. Nearly all of the thermal generating capacity from coal-fired and natural gas-fired power plants in the Railbelt is more than 20 years old, and much of it is more than 30 years old. The Turnagain project would provide the main populated region of Alaska with inexpensive renewable energy that would not produce greenhouse gasses and can be constructed in an environmentally friendly way, the company said.

The project calls for the use of the turbine supplier’s “Blue Energy Tidal Fence,” which will use the Davis Turbine to generate electricity with the movement of the tides in the Turnagain Arm of Cook Inlet. The Davis Turbine is a low-cost and simple mechanical device  that employs a hydrodynamic lift principle, causing vertically oriented foils to turn a shaft and a generator faster than the speed of the water.

The turbine was developed by Barry Davis in the 1980s under a grant sponsored by the National Research Council Hydraulics Laboratory in Ottawa, Canada, and Energy Mines and Resources Canada. His work evolved from a vertical axis wind turbine concept patented by Darrieus in 1929, into a tidal current driven turbine. This turbine is comprised of vertical hydrofoils attached to a central shaft transmitting torque to a generator. The kinetic energy from tidal flows can therefore be efficiently harnessed and converted to electrical energy, the company said.  

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.