Ocean energy . . . continued
Photo of Atlantic Ocean off Hull, MAPhoto of Hull Municipal Light Plant's Vestas wind turbine, Hull, MAPhoto of Hull 2 wind turbine, Hull, MAPhoto of Hull 2 1.8 MW wind turbine, Hull, MAPhoto of IBEW union's wind turbine, Dorchester, MASustenance logo
Photos: (1) Atlantic Ocean off Hull, MA (2) Hull Municipal Light Plant's municipally owned Vestas 660 kW wind turbine ("Hull 1") on the shores of Massachusetts Bay, Hull, MA (3) Hull 1 shown on its monopole mounting (4) Hull Municipal Light Plant's 1.8 MW wind turbine ("Hull 2"), also at the coastline, Massachusetts Bay, Hull, MA (5) IBEW union's wind turbine at its Dorchester, MA office building, near the Massachusetts coast

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Could the ocean power New England? . . . concluded

The third type of off-shore wind is deep water wind energy, or so-called "Blue H" technology. These wind turbines will likely be mounted on floating platforms. Such projects have been tested in 1/3 scale projects, but they haven't been tested in New England's ocean environment. Longer underwater electricity transmission cables will likely add significantly to the cost of deep water wind projects. On-line full scale versions of such projects are probably five to ten years in the future, Miller suggested. Because of deep water wind's stronger force, they offer the potential to generate 14 times the energy of shallow water wind projects. "That's where the energy is, so sooner or later we are going to go out there and get it," said Miller.

Miller showed photos of a variety of wave-energy technologies that have been tried. So-called "over top" projects allow the wave to spill over and into a funnel with the wave driving a electricity-generating turbine below. "Oscillating water column" technology would use the force of the wave to compress air, mimicing natural shoreline "blow holes," with the resulting compressed air driving a turbine.

"Attenuators" have articulated sections that move with the waves, pushing hydraulic fluid that powers an electrical generator. A large-scale Portuguese pilot project was up and working, but unfortunately the equipment was pulled on-shore for upgrades when the financial crisis hit, and the pilot company went out of business before the attenuator was placed back in service.

"Point absorbers" use buoys moving up and down in the waves to pump hydraulic fluid to drive a generator. The first FERC-licensed point absorber project, of the "AquaBuoy" company on the west coast, was abandoned, however, when the company could not get its equipment to perform. Another technology, the "Oyster," used a hinged device compressed by waves to pump hydraulic fluid to power a generator.

Unlike wind energy, where almost everyone has settled on a three-blade horizontal axis turbine as the most favored technology, there has been no consensus on the best approach for wave-energy, according to Miller. "These guys are just starting . . . no one's figured out the best way to do it," he said.

Miller also described a number of tidal energy projects. These essentially involve an underwater propeller or turbine driven by tidal flow in a high-velocity tidal flow location. Verdant Power has a tidal project with six such propellers anchored in the East River in New York, but has had repeated problems with propeller blades cracking, Miller noted. Marine Current Turbines, generating 1.2 megawatts from tidal energy, is the first tidal energy project to plug into the electric grid, in the United Kingdom. Some companies are also experimenting with helical turbines, first developed at Northeastern University, and with vertical tidal turbines, which have the advantage of keeping the electrical generators up above the water surface, reducing waterproofing issues.

Miller said that tidal generation requires a location where the tidal flow is moving at a minimum of 5 nautical miles (nauts) per hour, which limits the locations where tidal generating stations could be considered. The only Massachusetts location known to have a 5 naut tidal flow is a channel between Martha's Vineyard and Nantucket, he said.

Ocean thermal generation is also being explored off Hawaii. There the temperature differential between the top of the ocean and the depths is used in a heat pump arrangement for generating power. Miller said that ocean thermal was most likely to work in the Caribbean and other equatorial waters. Energy generation in ocean current areas, for example, in the Gulf Stream, are also being considered. The difficulty, said Miller, is that such currents are typically only around 1 naut in speed, making them inefficient electricity-generating sources with today's technology.

Survivability is a real challenge in all marine energy projects, as the ocean is a harsh environment, Miller said. Scotland and the U.K. are 'way ahead of us' on this, he said, using phased design and testing to work through equipment issues before building full-scale versions. The European Marine Energy Centre in Scotland is the only marine renewable generating testing center, said Miller. MREC hopes to develop one or more similar New Engalnd area ocean testing locations, pre-permitted, to reduce the huge costs of permitting just to test pilot equipment. MREC is looking at a number of possible ocean energy testing locations, including off Martha's Vineyard, at the Mass Maritime Academy on the Cape Cod Canal, in Edgartown, MA on Martha's Vineyard, at a Long Island Sound location, on the moorings at NH's twenty-year-old off-shore aquaculture site, and under the General Sullivan bridge in Portsmouth, NH where the pinched basin there causes rapid tidal flow in both directions.

The regulatory process for siting marine energy facilities is complex, even for testing, Miller explained. The Federal Energy Regulatory Commission (FERC) and the Marine Mineral Service (MMS) both have federal permitting jurisdiction for different aspects of such facilities, and depending on location, the Army Corps of Engineers can also be involved. FERC and MMS have different rules, and different application and award processes, complicating permitting. If the project is within three miles of shore, state agencies also have jurisdiction. Miller praised Massachusetts for its foresight in developing an ocean spatial management plan, designating certain areas in its three-mile coastal zone as off-limits for such facilities, some areas that may be appropriate for energy facilities, and others that need more examination.

Despite the obvious technical challenges, Miller was optimistic when asked about the future for marine renewable energy. He said that, in a 5 naut tidal location, tidal-powered electricity generation was aleady "close to economically viable" at 5-9 cents per kilowatt hour (kwh), compared to coal at about 4 cents / kwh. Electricity from shallow water wind is running about 12-15 cents / kwh, also "not bad at all," he said.

Venture capitalists have been hesitant to invest in marine renewable energy, however, because of its high capital costs. "This is a place where the government's very valuable in putting the seed money in to get these things going," Miller suggested. He noted that in the last year of the Bush administration, the administration requested zero money for marine renewable energy, but Congress put in $3 million. The following year Congress put in $10 million for it. This year Congress upped the figure to $40 million. When asked what it would take to change the framework of the energy world to shift to such renewable sources, Miller answered, "put a tax on carbon, if it's high enough, you'll get those decisions."

Miller concluded by saying "in case you have any doubts about my commitment to marine renewable energy, this is what I do for fun," showing a photo of himself rowing as part of a small whale boat crew in the ocean. "That's real renewable energy," he joked, "although I've definitely discovered that every year the amount of [that] renewable energy gets to be less and less."

The New England Marine Renewable Energy Center is based at UMass Dartmouth. It has received funding from UMass, the Mass Technology Collaborative, and the Department of Energy. MREC has organized several Ocean Energy for New England conferences, and in 2008 launched the University Research Consortium, comprised of a number of universities and colleges in New England and Scotland "to encourage research into marine renewable energy technologies." The Consortium includes several of the UMass campuses, MIT, the Woods Hole Oceanographic Institution, and the University of Edinburgh, among others. Next year MREC is planning to hold its Ocean Energy seminars in conjunction with the annual New England clean energy conference.

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