Hydropower

Marine Hydrokinetics

Issue 2 and Volume 33.

NSF awards grant for underwater kite research

A three-year, US$300,000 grant from the National Science Foundation will allow David Olinger, associate professor of mechanical engineering at Worcester Polytechnic Institute (WPI) in Massachusetts, to conduct research on developing a new form of ocean energy.

The research builds on Olinger’s prior research, funded by NSF and the U.S. Environmental Protection Agency, in which he developed a low-cost kite system that used wind to generate power. Olinger and a team of graduate students developed computational models that predict trajectories and power output for kites of different sizes and tethers of different lengths, which can be used to design kites capable of flying in stable, high-speed figure-eight patterns under changing weather conditions.

The same algorithms can be applied to the design of underwater kites, Olinger said. However, “instead of moving air, you have moving water and the kites have rigid wings.”

Olinger will now evaluate designs for undersea kites and explore methods for tethering them to floating platforms similar to those used for oil and gas rigs. WPI said the team will also examine the advantages and disadvantages of mounting turbine-generators directly to the kites or placing the generators on the platforms.

The final stage of Olinger’s research will see the construction of scale models, which will be tested in water tanks at WPI and the Alden Research Laboratory.

Olinger said the underwater kites potentially offer a number of advantages over stationary marine hydrokinetic (MHK) units.

“For one, the generators can be smaller, since with the figure-eight motion the kite will move three to five times faster than the current, greatly amplifying the power output – which could be as much as 64 times greater than the output of a comparably-sized stationary turbine,” Olinger said. “And since the kites will be attached to floating platforms, rather than located on the sea floor, they will be substantially less expensive to install and easier to retrieve for maintenance.”

FORCE, Nortek Scientific introduce new tool for tidal developers

A new instrument designed to provide high-resolution, real-time measurements of turbulent water flow at turbine hub height will make it easier for marine energy developers, researchers say.Called the “Vectron,” the instrument was developed by the Fundy Ocean Research Center for Energy (FORCE) in partnership with Nortek Scientific.

Vectron is the first tool of its kind in the world, FORCE said, and will be critical to understanding tidal turbine performance as it allows users to capture accurate measurements of turbulence at specific heights.

The FORCE test site – located in Nova Scotia’s Bay of Fundy – has a tidal flow equaling more than 14 billion tons of water at speeds exceeding 5 meters per second. Understanding the environment is critical to turbine design, the group said, as it will allow designers to unlock the bay’s potential.

The device will be deployed on FORCE’s Fundy Advanced Sensor Technology (FAST) platform, which is designed to monitor and characterize the site using onboard equipment.

Before Vectron was developed, FORCE said most tidal speed measurements have been taken using acoustic Doppler current systems.

ORPC to help develop marine power project off Alaska coast

Resolute Marine Energy has selected Ocean Renewable Power Company’s subsidiary, ORPC Solutions, to provide project management and regulatory affairs services for RME’s Yakutat Wave Energy Project in Alaska.

Located on the Gulf of Alaska, Yakutat is a remote community of 650 that relies entirely on diesel fuel transported by barge from Washington. The 1,000-mile trek has driven fuel prices as high as US$8 per gallon, ORPC said, threatening the area’s economic and social viability.

A preliminary permit granted by the Federal Energy Regulatory Commission (FERC) earlier this year shows plans for a 750-kW installation that would use ORPC’s SurgeWEC devices. The developers are now working with a number of regulatory agencies to obtain the date necessary for a formal license.

“ORPC’s demonstrated success in permitting marine hydrokinetic projects and the company’s strong relationships with regulatory agencies will be of great benefit as we move from preliminary to final permit status and start deploying our wave energy converters in 2015,” RME co-founder and Chief Executive Officer Bill Staby said. RME is a marine and hydrokinetic development company based in Boston.