Pacific Division, Naval Facilities Engineering Command / Third Naval Construction Brigade
Vol. 43, No. 12 / December 2001
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The power of waves - Hawaii's waves a potential source of renewable energy By Don Rochon, PACDIV Public Affairs Officer Sometimes, even the most common things turn out to be something extraordinary. Take for instance the new Office of Naval Research (ONR) sponsored project that PACDIV is working on. In a project full of potential far-reaching proportions, the ocean surrounding Hawaii will be used to generate electricity.
No, that’s not a misprint. Utilizing its Small Business Innovative Research (SBIR) program, ONR has contracted with Ocean Power Technologies, (OPT) Inc. of New Jersey to develop and deploy a system that will convert the mechanical energy of ocean waves into electricity. The SBIR program is well known for its dual use technological opportunities -- technologies that have both military and civilian applications to it.
Public support Public meetings were recently held in Kailua and at the State Legislature to provide information about the project; initial reaction seemed to be very supportive. A candidate site for the project is an area approximately 3,500 feet off Marine Corps Base Hawaii (MCBH); accordingly, Windward Neighborhood Boards were some of the first groups briefed.
Potential economic and environmental benefits are readily apparent for a larger scale project. The demonstration project off MCBH, however, is principally intended to develop and validate the technology base required to design and reliably operate wave energy converters in the ocean and connect them to an electrical grid.
New technology OPT has been producing this technology for a few years now; 1997 was the first year they conducted ocean tests on it. They improved the design in 1998 before testing and validating a prototype in 1999. Currently, PowerBuoyTM systems are scheduled to be deployed off the coast of New Jersey by the end of this year and off the coast of Australia by early next year.
OPT first developed the technology with a SBIR contract from ONR to develop a wave power system to generate small amounts of electricity for recharging batteries onboard remote underwater vehicles at sea, instead of having to bring them back to shore to do it. The successful results of these initial low-power wave energy converters led the Navy and members of Congress to realize the potential benefits of expanding the scale of the buoys to produce power suitable for connecting into an electric power grid.
Hawaii's ideal waves If waves are so ubiquitous, why was Hawaii chosen as the place for the project? According to T. W. Thorpe in a paper titled, "Current Status and Developments in Wave Energy" delivered to the 2001 Marine Renewable Energy Conference, "There are several regions around the world with high incident wave power levels." Hawaii is one of them. It just so happens that Hawaii has some of the highest annual mean power of waves per square meter of wave front. In other words, every square meter of wave front generating in Hawaiian waters has on average some of the highest recorded wave power around the world. And this project hopes to take advantage of it.
"Besides Hawaii having some of the best wave action required for power generation, the climate here is ideal for working year round, collecting the data we need," explained Kendall Kam, PACDIV BOS 16 electrical engineer. The data collection period is planned for between two and five years. "Also, the location where we want to place the buoys in the waters off the Marine Corps base is close to shore, which will help in transmission load requirements of the underwater cable."
The benefits of wave energy
A powerful system In addition to the obvious electrical prospective, data collection will also focus on ocean survivability. Earlier attempts at wave power energy generation did not fare so well because of the formidable ocean forces that are inherent at sea. The PowerBuoyTM system that will be installed was specifically designed with this thought in mind. A U-joint at the base will help protect the buoy in large ocean swells associated with the high winds and surf of hurricanes and tropical storms. Instead of the buoy withstanding all the pressures itself, the U-joint will allow the buoy to lie down in the water if ocean forces become too great, thereby distributing some of these forces away from the buoy. This concept allowed a similarly designed buoy to withstand Hurricane Bonnie off the coast of New Jersey.
Safety was also a primary design factor, with controllers (computers) built in to constantly monitor system performance, relaying real-time information back to shore. If a fault or a connectivity break of any kind is detected, the system could be shut down immediately. There is also a Global Positioning Satellite (GPS) device attached, so if the buoy ever did separate from its moorings, an electronic signal will notify the appropriate personnel so corrective action can be taken.
PACDIV’s involvement Kam is the on-site project manager and is coordinating the environmental study of this promising project with PACDIV’s Environmental Planning Division (PLN 23), and with the Naval Facilities Engineering Service Center (NFESC). PLN 23 has submitted a request for proposal to a Hawaii engineering firm to conduct all required environmental assessments and permits needed in accordance with the National Environmental Policy Act (NEPA). This assessment period will take place before any buoy is deployed. Current planning projections call for deployment of the buoys in early 2003.
In addition to PACDIV’s involvement, ONR is the program manager, NFESC will provide project management and technical oversight, and OPT is the contractor for the project. "It’s a great team to be working on," stated Kam. "I’ve been working with some really impressive people for over six months now on this project, and we all can’t wait to see the data that will be generated after we deploy the buoys." |
For
this project, two to six buoy-like structures (called the PowerBuoy