Emerging technology gives renewable tidal energy a chance
By JAMES NEGRI/ecoRI News contributor
The next big thing in renewable energy may be well out of sight, but not out of mind for the beneficiaries of an evolving form of sustained, environmentally friendly source of electricity: marine hydrokinetics.
Although still emerging from its nascent stage, marine hydrokinetics, or tidal energy, is starting to make its presence known in the Northeast. As the need for large-scale renewable energy grows, those in the industry are optimistic that, when achieved, homegrown tidal energy will be revolutionary in this field.
“There is a definite ability to generate the technology from the region, for the region,” said John R. Miller, executive director of the Marine Renewable Energy Collaborative (MRECo) in Marion.
Marine hydrokinetics is often compared to wind energy, which is well ahead technologically. Conceptually, underwater turbines are similar to wind turbines. A current spins the propeller, which then activates a turbine. That motion enables a generator to convert the energy into electricity. The problems for tidal energy lay mainly in the price tag attached to the development of viable equipment.
Miller said tidal power may never deliver the same share of power as wind to the global renewable-energy mix, but tidal energy is more predictable and dependable.
MRECo is part of the concentration of marine-science technology along the East Coast and in southeastern Massachusetts that is emerging as the source for some of the nation’s most noteworthy and commercially viable tidal-energy systems, called arrays.
The Massachusetts Maritime Academy in Buzzards Bay is taking a strong initiative in supporting marine hydrokinetics. Last year, the school announced a $7 million plan to build a tidal-energy dock jutting out from Taylor’s Point at the end of the Cape Cod Canal, where the academy is located. The two-phase project will result in a pier extending 250 feet south, then angle out toward the canal and continue another 950 feet.
Capt. Thomas Bushy, of the Massachusetts Maritime Academy and the project manager for this installation, is optimistic about the future of the project. Mass. Maritime recently received confirmation of a $2 million state grant to help the dock reach its full proposed length. Last year, the project received a $1 million state grant that came with two caveats: $150,000 must fund a turbine and $850,000 must support further research.
Mass. Maritime is working with a German company to buy a $150,000 turbine. The remaining $850,000 will fund hydrokinetic research collaborations with the University of Massachusetts Dartmouth and Bristol Community College in Fall River.
The proposed dock extension at Mass. Maritime will wrap around the T.S. Kennedy, the on-campus educational vessel. The dock will become a test site for hydrokinetic turbines, which Bushy said will help public research efforts and assist private renewable-energy development companies. Mass. Maritime hopes to obtain the initial building permits for the project early next year. After awarding contracts, construction is expected to start in May.
Beyond the price of equipment, testing and permitting can consume 70 percent of the cost required to implement hydrokinetic systems. “The permitting process is very arduous,” Bushy said.
Unlike wind energy, tidal energy must cope with several damaging elements underwater, such as wave action, sediment and corrosion.
“The ocean is just plain mean,” said Geoff Cowles, associate professor at the School for Marine Science and Technology at UMass Dartmouth.
Cowles is conducting modeling and other research to make turbines more adaptable to the harsh underwater conditions and to determine the amount of energy an array can harvest. His research is helping local projects advance, such as those underway at MRECo. The nonprofit collaborative has been integral in the push for hydrokinetic power generation in the region.
After leaving the Advanced Technology Manufacturing Center at UMass Dartmouth, Miller started MRECo. He knows the price for testing this technology is incredibly expensive, and the lack of funding from private investors can be a deterrent. “It’s always hard finding money,” he said.
In addition, there is a lack of fortified testing facilities in southern New England. The University of New Hampshire and the University of Rhode Island both have testing tanks designed for testing small-scale tidal systems, but full-sized testing is necessary for the technology to advance.
Miller said testing from barges is less than optimal because their lack of stability can compromise the research.
Limited testing of a turbine, however, is happening at the U.S. Geological Survey’s Conte Fish Laboratory in Turner Falls, Mass.
Miller is optimistic about the potential of establishing a testing facility not far from MRECo’s office. With permission from the Army Corps of Engineers, MRECo is considering its own testing facility adjacent to the railroad bridge that crosses the Cape Cod Canal. Miller said the strong current in the canal exceeds the 4-knot speed needed to generate tidal power. MRECo is planning to test a turbine, designed in Germany, in about a year, which would demonstrate the canal’s ability to power a rechargeable fuel-cell battery.
Southeast of the Cape Cod Canal, between Martha’s Vineyard and Nantucket, is the Muskeget Channel. Due to its strong tidal current, the channel has been chosen as a site for a tidal-energy project. Edgartown spent $2 million surveying the site. The project is nearing the stage of receiving its operating license for a five-year, 5-megawatt array. Edgartown, in collaboration with MRECo, has agreed to dedicate one turbine for testing, which would become the first full-sized test facility in the region.
In 2011, a turbine designed by the Boston-based Free Flow Power Corp. was tested in the Muskeget Channel, with the help of a $98,000 grant from the Massachusetts Clean Energy Center and a Mass. Maritime barge.
Outside of southern New England, there are several noteworthy projects. In 2012, the Ocean Renewable Power Co. (ORPC), based in Portland, Maine, conducted the first federally licensed tidal-power tests on a commercial scale in Cobscook Bay, Maine. Located near the Bay of Fundy, in the Minas Passage, this area is home to the strongest tidal currents on the East Coast. According to a study by Acadia University in Nova Scotia, the passage contains nearly 7,000 megawatts of energy, 2,500 of which can be extracted without severely altering the tidal range.
The current’s enormous strength was proven in 2009 when it destroyed turbines being tested by the Fundy Ocean Research Center (FORCE) in Nova Scotia. The blades of the turbines broke within three weeks of their installation. FORCE has continued improving its data collection in the area to ensure greater success for future projects in the passage.
The site remains an epicenter for the industry, as companies such as Lockheed Martin develop new turbines. Verdant Power, based in Roosevelt Island, N.Y., is another pioneer in the field. The company is developing a tidal-energy project in Manhattan’s East River that is expected to set a strong example for this potential energy source. An array of 30 turbines, scheduled for completion next year, is designed to generate about a megawatt of power, about as much as one commercial-scale wind turbine. This electricity will be distributed to 9,500 New York residents. Verdant also hopes to use the electricity generated by the river’s strong tidal flow rate to power car-charging stations, giving New York the first tidal-powered cars.
Current work at UMass Dartmouth, Mass. Maritime, the University of Rhode Island, Brown University, Massachusetts Institute of Technology and the Woods Hole Oceanographic Institute supports Miller’s claim that, “Within 100 kilometers of Boston is arguably the greatest concentration of ocean engineers and scientists in the world.”
MRECo, Miller said, is already at work on other projects with universities and municipalities in New England, such as bringing tidal power and other renewable energy to places such as Cuttyhunk Island that are unconnected to the power grid and completely powered by fossil fuels.
Although more research and testing is needed, Miller believes the advancement of testing facilities and data collection along the East Coast will permit the marine hydrokinetics industry to advance, providing a new form of renewable energy.
James Negri is a journalist and a senior in the civil and environmental engineering program at UMass Dartmouth.
This story was funded through a grant from the Marion-based Island Foundation. It's the second article in a four-part series on grassroots renewable-energy efforts ongoing in southern New England.