Potential Impacts of Hydrokinetic and Wave Energy Conversion Technologies on Aquatic Environments

Opportunities and constraints for wave energy conversion technologies and projects are evaluated by identifying and characterizing the dominant wave energy systems for United States (US) coastal waters using marginal and joint distributions of the wave energy in terms of the peak period, wave direction, and month. These distributions are computed using partitioned wave parameters generated from a 30 year WaveWatch III model hindcast, and regionally averaged to identify the dominant wave systems contributing to the total annual available energy ( A A E ) for eleven distinct US wave energy climate regions. These dominant wave systems are linked to the wind systems driving their generation and propagation. In addition, conditional resource parameters characterizing peak period spread, directional spread, and seasonal variability, which consider dependencies of the peak period, direction, and month, are introduced to augment characterization methods recommended by international standards. These conditional resource parameters reveal information that supports project planning, conceptual design, and operation and maintenance. The present study shows that wave energy resources for the United States are dominated by long-period North Pacific swells (Alaska, West Coast, Hawaii), short-period trade winds and nor’easter swells (East Coast, Puerto Rico), and wind seas (Gulf of Mexico). Seasonality, peak period spread, and directional spread of these dominant wave systems are characterized to assess regional opportunities and constraints for wave energy conversion technologies targeting the dominant wave systems.

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Wave Power for U.S. Coast Guard First District Lighthouses

Solar Energy ◽

10.1115/isec2005-76105 ◽

2005 ◽

Cited By ~ 1

Author(s):

Andy Walker ◽

Alicen Kandt ◽

Donna Heimiller

Keyword(s):

Energy Conversion ◽

Wave Energy ◽

Alternative Energy ◽

Energy Content ◽

Energy Resource ◽

Coast Guard ◽

Wave Power ◽

Wave Energy Conversion ◽

Submarine Cables ◽

Conversion Technologies

Lighthouses and other navigational aids are situated near tumultuous seas and thus may be good candidates for early applications of wave energy conversion technologies. The U.S. Coast Guard First District is converting lighthouses’ electrical systems to solar power to divest itself of electrical submarine cables and overhead costs associated with cable maintenance. However, in some lighthouses solar conversion is impractical or may compromise historic preservation. Unless alternative energy sources become available for these locations, they will continue to use submarine cables to run on shore power. Lighthouse sites for which shoreline and wave characteristics are suitable would be good candidates for a wave energy demonstration project. This paper describes gravity wave physics and the characteristics of mechanical radiation (growth, propagation, diffraction, and shoaling). A simple expression for energy content of a wave train with a two-parameter Bretschneider spectrum is applied to spectral wave density data collected from 15 buoys to evaluate wave energy resource potential at 31 candidate lighthouse sites in New England. Annual average wave power per meter of wavecrest varied from 3.9 to 21.7 kW/m at the buoys, and from 3.9 to 9.2 kW/m (with an average of 5.0 kW/m) at the lighthouses (buoys with maximum wave power are far out to sea, but still influence the correlation). The performance characteristics of two types of wave energy conversion technologies are used to calculate annual energy delivery by way of example. The paper concludes with a discussion of economics and environmental and permitting issues. It identifies Seguin Island light off a point in Maine and Nauset Beach, Chatham, Nantucket, and Sankaty Head lights (on Nantucket Island and along the outer shore of Cape Cod) as the best sites to begin more detailed evaluations, based on a comparison of wave power and utility rates. Subsequent studies would include demand profile for lighthouses, supply profiles, and resulting storage requirements.

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