Ocean energy is divided into in-stream tidal and wave energy.  All ocean technologies are in the pre-commercial stages, with European manufacturers and research institutes, particularly in the United Kingdom, leading the way.

In-stream tidal energy technology consists of many designs, but all convert the kinetic energy of the flowing water into electricity, most using some type of turbine.  Turbine designs range from underwater wind turbine-style, to vertical- or horizontal-axis cross-flow turbines.  The most mature and tested designs have been in place at the European Marine Energy Centre (EMEC) in Scotland since 2008.  (Please see the Device Assessment or the Manufacturer sections for links to pictures and further information).  Since in-stream tidal energy derives into power from the tides, the power production is a highly predictable, if not constant, power source.

Wave energy conversion (WEC) devices are also in the pre-commercial stage.  As an emerging technology, a wide array of designs aim to convert wave energy into electricity.  From heave devices, like the Pelamis, to oscillating water columns, to single buoys riding the waves in the open ocean, a great many potential designs are being tested around the world.  While not as consistent as the tides, the amount of potential wave energy is frequently predictable days in advance.

River in-stream energy conversion (RISEC) devices work in a similar manner to tidal devices, but generally on a smaller scale.  In the summer of 2008, Ruby deployed and tested the first river hydrokinetic device in Alaska, a 5 kW New Energy Encurrent turbine.  A picture of the turbine is included to the right.

AEA is a participant in a multi-state evaluation of tidal and river energy technologies led by the Electric Power Research Institute (EPRI).  According to EPRI, Alaska has extensive tidal energy resources and over half the nation's potential wave energy.

As part of the Renewable Energy Fund, AEA is party to a number of Alaska river hydrokinetic studies.  The first is a multi-site hydrokinetic study being implemented by the University of Alaska Anchorage.  In the summer of 2009 it characterized the hydrokinetic resources at more than a dozen villages.  Also through the RE Fund, AEA is providing support for the University of Alaska Fairbanks’ Nenana hydrokinetic test center.  Lastly, the village of Iguigig received funding for a pilot project in the Kvichak River.

If you are interested in receiving e-mail updates on Ocean and River Energy, please add your e-mail address to the AEA Ocean River Energy Distribution List at the following link: http://list.state.ak.us/guest/RemoteListSummary/ocean_river_energy_wg

Neil McMahon, Assistant Project Manager
Geothermal and Ocean and River Energy Programs
Tel. (907) 771-3027
Fax (907) 771-3044
E-mail: nmcmahon@aidea.org