Close 

The Leading Edge

FORCE advances work on getting tidal units in water

The subsea power cables required to deliver electricity from tidal projects in the Bay of Fundy have arrived at the Fundy Ocean Research Centre for Energy (FORCE). When connected, the 11 km of cables will give the center the largest transmission capacity for tidal power in the world at 64 MW, says Matt Lumley with FORCE.

FORCE, in the Minas Passage area of the Bay of Fundy in Nova Scotia, Canada, also opened a 3,000-square-foot visitor center in November 2011. The center offers information, videos and interactive displays related to tidal energy and the bay.

FORCE, which receives funding support from the government of Canada, province of Nova Scotia, Encana Corp. and participating developers, is scheduled to host four tidal technologies in 2012. Its berth-holders are Atlantis Resources Corp. and Lockheed Martin, Nova Scotia Power and Open Hydro of Ireland, Minas Basin Pulp and Power and Marine Current Turbines, and Alstom of France and its Clean Current technology.

DOE reports ocean resources can provide 15% of electricity by 2030

The U.S. Department of Energy released two reports in mid-January detailing the country's ocean wave and tidal resource energy potential. Mapping and Assessment of the United States Ocean Wave Energy Resource report is a follow-up to EPRI's 2004 study, with the most recent evidence suggesting a 26% increase in wave energy resources.

The Assessment of Energy Production Potential from Tidal Streams in the United States, led by researchers at Georgia Tech Research Corp. in collaboration with DOE, is the first of its kind in the U.S. and includes a geographic information systems (GIS) tool for public use. The report data concludes that U.S. water power resources, including ocean wave, tidal and conventional hydropower, have the potential to provide 15% of electricity in the U.S. by 2030.

"The release of both reports demonstrates the attainable energy potential of our nation's vast ocean resources," said Sean O'Neill, president of the Ocean Renewable Energy Coalition, a trade association dedicated to promoting marine and hydrokinetic renewable energy technologies from clean, renewable ocean resources. "DOE's investment in these studies, as well as the corresponding results, is a testament to the importance of our unique opportunity to pursue a diverse energy portfolio that includes wave and tidal energy in an effort to secure our energy supply, create jobs and lower greenhouse gas emissions."

The reports are the most rigorous assessments undertaken by DOE and its collaborative partners and show the significant contributions that waves and tidal currents off of U.S. coasts could provide to the grid. DOE announced the information in the resource assessments could "help to further develop the country's significant ocean energy resources, create new industries and new jobs in America, and secure U.S. leadership in an emerging global market."

The wave energy assessment concludes that the Pacific Ocean encompass the greatest available wave energy resource in the U.S. The report also outlines the wave energy potential along the East Coast from Maine through North Carolina and from South Carolina through Florida, as well as in the Gulf of Mexico, Alaska's Bering Sea, Hawaii and Puerto Rico.

East Coast startup working on wave-energy converter prototype

With the backing of a $1 million grant from the U.S. Department of Energy, Resolute Marine Energy is launching a pilot program that is expected to yield a wave-energy converter prototype.

Located in Newburyport, Mass., RME is still gathering data to prove that its technology has commercial value. The first live trials could take place this summer.

According to Chief Executive Officer P. William Staby, Nantucket, Mass., has tentatively been chosen as the test site in part because UMass Dartmouth is providing logistical assistance for research.

The grant is also being used to help the company conduct research activities designed to verify and optimize the performance of its patent-pending SurgeWEC technology.

RME recently announced it had successfully completed limited trials of its prototype on the North Carolina coast. RME officials told the Newburyport News, that their prototype is "a near-shore, surge-type wave energy converter that is mounted on the sea floor just outside the surf zone and captures energy from waves that pass overhead."

Slow currents have Campbell River refocused on research

The city of Campbell River could lead Canada in developing energy from the ocean tides, according to an organization pushing for ocean energy in British Columbia. Situated along Discovery Passage, Campbell River could be the place where the tidal energy industry is developed, said Chris Campbell, executive director of Ocean Renewable Energy Group, which supports ocean energy projects across Canada.

"The reason why Campbell River keeps coming up and why national companies look here is Discover Passage includes five of the top 50 Canadian (tidal power) sites," Campbell told the Campbell River Mirror. "This is an industry yet to be developed. There are no suppliers, which translates into an opportunity for researchers and an opportunity for the region to be a leader as this industry is designed."

The city led a tidal power assessment study last year, the first municipality in British Columbia to do so, and results indicated that currents around the fishing pier are not fast enough to power electricity. However, the area is suitable for research and demonstration purposes.

Campbell said that Ocean Renewable Energy Group and other marine energy proponents will be writing a letter to the provincial government asking the cabinet to enable BC Hydro to offer "enhanced standard-offer" contracts for a small group of pioneering wave and tidal projects.

Air Force Academy tests wave energy converter

Aeronautics researchers at the U.S. Air Force Academy in Colorado have completed testing of an ocean wave energy converter in a wave tank at the Offshore Technology Research Center in College Station, Texas.

Work on this converter, called the Cycloidal Wave Energy Converter, began in 2008 with a National Science Foundation grant to create the first free-floating, fully submerged wave energy converter that generates power from deep ocean waves. The original concept was tested at the 1:300 developmental scale. The most recent unit tested was at a 1:10 scale. This is the last step before building a full-sized ocean-going device, said Dr. Juergen Seidel, one of the researchers developing the technology.

A cycloidal turbine consists of one or more blades that are oriented parallel to a main shaft and attached at a radius. This technology is in use in the wind and marine propulsion industries. To be used as a wave energy converter, the unit needs to be synchronized to the incoming wave via an upwave sensor and feedback control system that controls the main shaft power takeoff and the pitch of the blades. Although the shaft can be oriented either horizontally or vertically, a horizontal orientation is favorable for deep ocean waves.

Scientists are using a research grant from the U.S. Department of Energy to increase the converter's technology readiness level from 3 to 4, on a scale of 1 to 9. Level 4 signifies that a component of a system has been validated in a field environment. Level 9 designates a mission-ready product that is ready for full-size, large-scale use.

In 2010, researchers incorporated under the name of Atargis Energy Corp.

Several issues were uncovered and resolved during this most recent round of testing. During the first submerged test of the generator, bubbles were observed coming from one of the gearboxes. When opened, this gearbox was half full of water and had to be further sealed to eliminate the leak. Researchers discovered additional leaks in the pylons that affected the actuators that control the pitch of the blades.

The completed tests confirmed the generating capabilities of the converter, said Dr. Stefan Siegel, developer of the technology. Researchers gathered detailed force and movement data that lined up with previous results from small-scale tests and simulations, he says.

Atargis plans to return to the offshore Technology Research Center in early 2012 to test the use of multiple wave energy converters at once. The tank allows testing of up to three converters simultaneously.

Instream Energy using BAE center to advance hydrokinetic turbine

International technology firm BAE Systems has agreed to grant Instream Energy Systems ongoing access to BAE's Advanced Technology Center to develop further Instream's hydrokinetic turbine technology. Instream, of Vancouver, is an early stage renewable energy company focused on development and commercialization of proprietary hydrokinetic power generation systems.

In 2010, Instream worked with BAE on a demonstration project at Duncan Dam, a BC Hydro storage dam on the Duncan River in British Columbia that regulates flows into the Kootenay River Basin. BC Hydro allowed Instream and Powertech Labs to install four 25-kW vertical-axis turbine-generators and systems developed by Powertech in the Duncan Dam tailrace to demonstrate the technology.

"The Instream demonstration project at BC Hydro's Duncan Dam underscores that a hydrokinetic system has a small environmental footprint, and has the potential to produce clean and renewable electricity on a commercial basis," BC Hydro Chief Technology Officer Kip Morison said.

Director John Rossall of BAE's Offset Programs said Instream expects to remove much of the business risk associated with the next generation of hydrokinetics as a result of its relationship with BAE, BC Hydro and Powertech.

Results released in testing of PowerBuoy wave energy unit

Wave energy technology company Ocean Power Technologies Inc. announces the results of tests it performed with its PowerBuoy system for the U.S. Navy.

The tests, performed off the New Jersey coast for the Navy's Littoral Expeditionary Autonomous PowerBuoy (LEAP) program, showed the PowerBuoy is capable of providing consistent power for offshore equipment and devices in a wide range of sea conditions.

Specifications of the project called for a payload power delivery on a continuous basis of 150 W, OPT says, though the actual output was significantly higher than expected. OPT's units supplied power in excess of 400 W for the duration of the deployment and produced peak sustained electrical power of 1,500 W. An on-board power management and storage system allowed the payload to be supplied with power during extended periods of zero wave activity.

The LEAP program was designed to help minimize the Navy's maintenance and fuel replenishment costs. Currently, systems requiring remote power at sea are often powered by diesel generators.

In other news, OPT will soon begin work on a new prediction model that is exected to boost the power output of the company's PowerBuoy systems. OPT's goal is to develop a system that will assess the characteristics of incoming waves before they reach the PowerBuoy wave stations - thus giving the energy-producing units more time to react. It is expected that this will increase the buoys' outputs while reducing the cost per MW hour of energy produced.

The project is being partially funded by a US$3 million grant from the European Union's Seventh Framework Programme and is part of a larger project called "WavePort."

WavePort is a multi-national consortium of companies that will use OPT's newest technology in a new PB40 PowerBuoy system that is to be built at an existing mooring site near Santona, Spain.

More HR Current Issue Articles
More HR Archives Issue Articles

To access this Article, go to:
http://www.hydroworld.com/content/hydro/en/articles/hr/print/volume-31/issue-2/departments/the-leading-edge.html