Turnagain Arm Tidal Energy Corp. has filed an application for a preliminary permit for the Turnagain Arm Tidal Electric Generation Project, TATEG, a proposal to use Cook Inlet tides to generate electric power.
Christopher D.L. Lee, president and CEO of Turnagain Arm Tidal Energy, told the Federal Energy Regulatory Commission in the company’s March 8 application that this plan differs in several ways from a previous project headed by his father Dominic Shi Fong Lee. The original project involved use of a specific turbine while the current proposal will study “appropriate market ready turbines,” the younger Lee told FERC. Also removed from the current project application is a proposed causeway across Turnagain Arm which would have been a project of the State of Alaska. The cost estimates for likely required studies have also been revised, Christopher Lee said.
Lee, the son of Dominic Lee, took over as the company president following the death of his father last summer. The previous application was withdrawn after Dominic Lee was unable to raise capital, an estimated $20 million, to get the project to the construction permit phase.
Current application
In the March 8 application the company said the goal of the application is to allow the company to “secure and maintain priority of application for a license for the project under Part 1 of the Federal Power Act while obtaining the data and performing the acts required to determine the feasibility of the project and to support an application for a license.”
The proposed term for this permit is 2021 to 2024.
The project would build two 8-mile tidal fences consisting of 1,000 megawatts of turbines each - a total of 2,000 megawatts of peak generating capacity, with a 1,200-megawatt baseline aggregate capacity.
“Many types of turbines are currently available on the market from suppliers around the world,” the company said. “The specific turbine make, model, and specifications will be determined during the preliminary permit phase.”
The turbine chosen “will likely have a rotor designed to be lift driven, much like the modern wind turbines,” the company said.
The tidal bridges would use stacked turbine units extending from the seafloor to the water surface.
The first tidal fence would stretch from just off Fire Island to Point Possession on the Kenai Peninsula, with a service road across the top allowing the turbines to be serviced from the Kenai side.
A second 7.5-mile tidal fence would be 5-7 miles south of Fireland Island and a minimum of 5 miles from the first tidal fence, a distance “needed to allow the tidal force to recover its strength after going through the first fence,” the company said.
The State of Alaska would have the option to build a causeway from Point Possession to Fire Island, some 15 miles.
Environmental issues
“The tidal bridge will have the advantage of being able to harness a large portion of the kinetic energy that flows through the channel, thus enabling reduced conversion losses due to resource by-pass. The blockage ratio of the tidal bridge will be on the order of 50%, leaving a significant part of the waterway open to sea life, sediment, and water flow,” the company said, with moving parts 30 feet wide and 30 feet long “so that the fish, whales, and other sea mammals can swim through without any difficulty.”
The rate at which the turbines turn can be compared to a revolving door at a hotel entrance - just without the glass, the company said. It said the project “can be designed to enable the free movement of fish and whales and produces no noise or other pollution when in place and operating.”
Proposed studies
Studies planned for the project include:
*Preliminary engineering study.
*Preliminary siting investigation.
*Study of current and near future projects of similar scope and size.
*Recommendation of design to suit the site.
*Current and near future turbine and kinetic energy transfer systems study.
*Current and near future electricity transmission systems study.
*Bathymetry study.
*Multiple studies likely to be requested by stakeholders.
Commenting on the proposed study of current and near future industrial battery arrays, the company said the battery arrays were an effort “to mitigate ‘brown out’ periods during slack tides.”
The company estimates $100 million in studies, including $25 million for preliminary engineering studies, $50 million for an environmental impact assessment and $25 million for public relations activities.
The company said it would raise private money for the studies phase of the project and said it has a commitment from an overseas investor for 20% of the project construction cost, estimated at $2 billion.
