Sunday, March 29, 2009

The Tide is in at Puget Sound

Puget Sound, near Seattle, Washington, is the subject of a number of tidal energy proposals. Though some site research proposals have been denied by the Federal Energy Regulatory Commission, or FERC, others are in the planning or pilot testing stages. These sites will help determine whether tidal energy is a feasible option for alternative energy in the United States. (1)

Traditionally, tidal energy has been captured by tidal barrages or fences, in which water from the tides is allowed into the structure and then released through turbines, which generate electricity. More innovative technology is planned for Puget Sound, where tidal turbines would be installed. The turbines are similar to wind turbines, but they will have to be sturdier because water is denser and will cause more wear on tidal turbines. Though the turbine will be more expensive and use more material to build than the barrages, tidal turbines will produce more energy. (2) Puget Sound is a likely candidate for tidal turbines, since in 20 to 30 feet of water, some currents along the coast reach the desired speed for energy generation. At an ideal current between 4 and 5.5 mph, a tidal turbine can produce the same power as a wind turbine four times its diameter. (4)

There have been many policies to increase alternative energy research, but who controls the domain of tidal energy policy has been disputed. On St. Patrick’s day, lawmakers reached an accord that will clear up disputes on offshore wind and tidal energy. Since 2007, the Interior Department and the FERC had qualms about who would have domain over, and therefore make rules for, offshore energy sources. Tuesday it was decided that the FERC will officially get to decide which tidal and wave energy projects it promotes offshore. (3)

The US Navy is planning research at Puget Sound that will aid the United States in improving their energy supply. Specifically this will deal with Kinetic Hydropower System, or KHPS, technology that will power Naval bases. This technology will use an array of tidal turbines to maximize energy generation with rising and receding tides. Policies drafted by the FERC will determine whether the Navy project and others at Puget Sound will be implemented. (3)


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