This report outlines the status of hydrokinetic power generation technology, the expected trajectory of improvement over the next five years, and recommended actions the state can take to accelerate this technology field. The report is based on numerous sources as well as data collected by ACEP over the past year at a hydrokinetic research site in Nenana, Alaska. Turbines placed directly in river, ocean, or tidal current generate hydrokinetic power from the kinetic energy of moving water (current). The available hydrokinetic power is a function of the density of the water and the speed of the current cubed. The minimum current required to operate a hydrokinetic device is typically 2–4 knots (1–2 m/s), but optimal currents are in the 5–7 knot (1.5–3.5 m/s) range. The Alaska region contains about 40% of the total U.S. river energy resource, 90% of the total U.S. tidal energy resource, and 40% of the U.S. continental shelf wave energy resource. Hydrokinetic turbines have frequently been discussed as an option for generating power in communities located along Alaska’s major river systems, and for tidal energy applications in Cook Inlet and coastal Southeast Alaska.
Challenges to developing a commercial hydrokinetic industry in Alaska include determining the technological, operational, and economic viability of hydrokinetic turbines, meeting permitting requirements, and gaining stakeholder acceptance. Hydrokinetic technology can be affected by debris, sediment, frazil, and surface ice; river dynamics (turbulence, current velocity, channel stability); and the interaction of turbine operations with fish and marine mammals and their habitat. The question of turbineoperation impacts on the aquatic environment is one of the major issues that will determine stakeholder and permitting agency views toward this new technology. The 2010 hydrokinetic turbine demonstrations conducted at Ruby and Eagle were significantly adversely affected by in-river debris floating on the surface and neutrally buoyant debris. These experiences indicate that developing technology to mitigate debris problems will need to be a high priority for practical hydrokinetic power production.
Alaska is well positioned to facilitate river and marine hydrokinetic technology (RMHT) as it transitions from emerging to developed technology over the next five to ten years, by building on current and planned national and state structures. These structures include the Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE, formerly the Minerals Management Service), the Department of Energy, and the Denali Commission, as well as Alaska state funding support for renewable energy projects and development of emerging technologies and research.