Firms see tidal energy as wave of future

November 25, 2010 By Bob Drogin

Moored in the channel, the little gray barge strains against a raging morning tide. The torrent soon will drain nearby rocky inlets and fishing harbors by 20 feet - as high as a two-story house - only to flood them again six hours later.

Tucked under the stern, horizontal turbines spin in the swirling current. The huge mechanism looks like an old lawnmower reel, but it is America's most ambitious effort yet to produce electricity by harnessing the of the moon and sun on the sea.

"This is cutting-edge," Ryan Beaumont, an engineer, said as he monitored the turbines from a control room on the barge. "No one has done tidal energy like this before."

"We call this the Kitty Hawk of tidal energy," said John Ferland, vice president at Ocean Renewable Power Co., owner of the project.

The start-up company aims to link a larger turbine system to eastern Maine's power grid next fall in the country's first small-scale commercial use of .

Tapping the tides is the latest niche in the search for affordable, renewable energy. Widespread use may be years off, but advocates say tides and other hydrokinetic systems, from to free-flowing rivers, ultimately could meet up to 10 percent of America's electric power needs - more than hydropower dams now supply.

Pilot projects or studies are under way in Washington's Puget Sound, in Alaska's Cook Inlet, off the coasts of Florida, California, Oregon and Hawaii, in New York City's East River, along the and elsewhere.

"These are coastal resources, and most people live along the coasts," said Hoyt Battey, a water power expert at the U.S. Energy Department.

"When you're talking about providing half the power of Alaska or Hawaii, or half the power of New York, that's significant."

For now, the technology for marine and hydrokinetic power remains in its infancy, and costs are prohibitively high. Ireland, Denmark, Portugal, South Korea, China, Australia and other nations have been testing the waters for years. Commercial operations are rare.

"Basically, it's much more difficult to do things underwater than on dry land," said Robert Thresher, research fellow at the National Renewable Energy Laboratory, a federal facility in Golden, Colo. "The water tears stuff apart. There's fish, rust, fouling ... all kinds of problems."

Canada may be closest to finding solutions. It is investing $75 million for three pilot projects in the upper Bay of Fundy, home to the world's highest tides. The first test turbine weighs 400 tons, has a peak capacity of one megawatt and looks like a sunken windmill.

"I believe if we can do it in Fundy, you can do it anywhere," said John Woods, who heads the authority that runs the projects. He hopes to gather enough data by 2015 to determine whether tidal power is technically feasible, environmentally safe and economically viable.

In theory, the U.S. resource is immense. Waves and currents are relatively reliable in some areas, and tides ebb and flood twice a day like clockwork. They thus are more predictable resources than wind or solar power.

Unlike wind, however, tides with sufficient range and velocity run only in the nation's northeastern and northwestern corners, mostly Maine and Washington, plus Alaska. Waves are consistently high only on the Pacific coast north of Point Conception, Calif., and in Hawaii.

Several developments suggest a surge of U.S. interest, however.

The Federal Energy Regulatory Commission reported this month that it has issued 140 hydrokinetic preliminary permits for proposals to tap tides, waves or river currents, up from a handful a few years ago. In many cases, officials said, applicants are staking claims in case the technology takes off.

In September, the Energy Department awarded $37 million in matching grants for the first time to companies with the most promising prototypes or that appeared close to commercial service. Several states and the military also have provided support.

Working with the Navy, for example, Ocean Power Technologies last month connected a small test buoy in the swells off Oahu to the power grid that serves the Marine Corps Base Hawaii, marking a first for a wave energy device in U.S. waters.

"We have demonstrated that our technology works, that it can survive in harsh ocean conditions and can deliver high-quality power to the grid," said Robert Lurie, a vice president of Ocean Power, which is based in Pennington, N.J.

Next spring, the company plans to anchor a larger power buoy in the waves off Reedsport, Ore., for further tests. The ultimate goal, Lurie said, is to build "multi-buoy wave farms" generating enough power to light 50,000 homes.

In Washington state, the Snohomish County Public Utility District plans to install two large turbines to gather tidal data half a mile offshore and 200 feet deep in Admiralty Inlet in Puget Sound.

"We would hope to operate for three years and then make a decision on whether to expand," said Craig Collar, project manager.

The industry has struggled so far to gain a foothold in California. Last month, Pacific Gas & Electric Co. suspended a proposed $50 million pilot project for wave energy near Eureka, citing the difficulty of obtaining permits and the high cost of development.

"It was a substantial investment for an unproven technology," said PG&E spokesman Brian Swanson.

He said the utility still was considering a 100-megawatt project in the seas off Vandenberg Air Force Base, near Santa Barbara.

"We are very committed to wave energy," Swanson said.

Proposals to exploit the colossal currents under the Golden Gate Bridge have hit the rocks, however.

"There is a great dispute over whether it's feasible because of the huge vortexes and turbulence," said Roger Bedard, former head of ocean energy at the Electric Power Research Institute, an industry think tank in Palo Alto. "The whole watershed of Northern California flows through this one-mile gap."

Tides in Maine's rugged Cobscook Bay, at the mouth of the Bay of Fundy, flow as fast as the average man can run. Fishing boats in Eastport, the easternmost town in the United States, rise and fall like toys in a bathtub. The currents create a giant whirlpool, called the Old Sow, that is treacherous for small boats. Vast tidal flats and seaweed-draped boulders emerge or vanish every few hours.

In 1935, at the height of the Depression, President Franklin D. Roosevelt backed a plan to build tidal dikes here to impound the seas for electric power. Roosevelt had spent summers on nearby Campobello Island in Canada.

But Congress soon canceled the project. All that remains is a tabletop model in the town museum, and an old March of Time newsreel with grainy footage of what the announcer called "a monument to disappointment."

Ocean Renewable Power Co., based in Portland, Maine, launched its first cross-flow turbine at Eastport in 2007. The helix-shaped design, with foils modeled like twisted airplane wings, was small and tethered to a former fish farm barge. But it worked.

The company built a bigger unit, with two sets of foils, and a high-tech barge, for $2.5 million. Both went in the water last spring, then came out for more tweaking. Testing resumed Oct. 1 in a fast-flowing channel flanked by wooded hills and rocky cliffs.

"They've put Maine on the map for tidal power," said Betsy Biemann, president of the nonprofit Maine Technology Institute, which supports emerging technologies that can benefit the state.

The environmental impact still isn't clear. University of Maine researchers are trying to assess the risk to fish, diving seabirds, seals and other creatures in a pristine ecosystem.

"We still have to show the turbines aren't a fish chopper or whale thumper," said Bob Lewis, who heads Ocean Renewable Power's onsite operations.

The goal is to deploy a turbine unit twice as big on the seafloor next fall. It will have a rated capacity of 150 kilowatts, enough to light 50 to 75 homes, and feed into the Bangor Hydro Electric grid.

If all goes well, four more turbines will be added a year later. The total estimated cost: $21 million, half from federal and state grants, the rest from private investors. The company hopes the turning tides can supply most of the region's electricity in six years.

"We're not going to replace nuclear plants," Lewis said. "But we can help. We can be part of the solution."

(c) 2010, Los Angeles Times.
Distributed by McClatchy-Tribune Information Services.

3.5 /5 (2 votes)  

Filter


Move the slider to adjust rank threshold, so that you can hide some of the comments.


Display comments: newest first

SiBorg
Nov 26, 2010

Rank: not rated yet
Interesting bit of kit, a similar concept came out of Oxford Uni (http://inhabitat....urbine/) and it seems like there are some definite advantages, in terms of the swept area, compared to the prevalent horizontal axis concepts. But in the end the real decider will be how easy they are to operate and maintain.
tarheelchief
Nov 29, 2010

Rank: not rated yet
I am surprised more energy companies are not converting their offshore platforms for refineries,for wind farms,for tidal power stations,for solar panel research.They have created a grid system to support these structures,and these same grids could be utilized by various utility companies.Instead of recycling these platforms as reefs,it might be helpful to utilize them in other ways.The potential for wind farms in the North Sea is just one place where you might see useful and economical conversions.
Rank 3.5 /5 (2 votes)
Relevant PhysicsForums posts

More news stories

Apple CEO Cook gives up $75M in stock dividends

(AP) -- Apple says CEO Tim Cook is giving up $75 million in dividends on restricted stock.

Technology / Business

created 3 hours ago | popularity not rated yet | comments 1

Computers excel at identifying smiles of frustration (w/ Video)

(Phys.org) -- Researchers at the Massachusetts Institute of Technology (MIT) in the US have trained computers to recognize smiles, and they have turned out to be more adept at recognizing smiles of frustration ...

Technology / Computer Sciences

created 10 hours ago | popularity 4 / 5 (2) | comments 1 | with audio podcast report

Beyond oil, can Alaska be tapped as a source for renewable energy?

Alaska has massive hydro, wind, geothermal and other renewable resources, but the state's rural villages are chained to diesel and suffer oppressive energy costs they say threaten their existence. Lawmakers, energy experts ...

Technology / Energy & Green Tech

created 4 hours ago | popularity not rated yet | comments 0

HyperSolar shows dirty water no barrier to power world

(Phys.org) -- The Santa Barbara, California, company, HyperSolar, is set to transparently share the ups and downs of its research experiences toward the company’s ultimate vision, successfully producing ...

Technology / Energy & Green Tech

created 23 hours ago | popularity 4.8 / 5 (14) | comments 17 | with audio podcast report

Researchers successfully test solar desalination system for arid land agriculture

Ben-Gurion University of the Negev (BGU) researchers have created a man-made oasis in the desert with the successful application of a solar-powered desalination system that provides water for irrigation in arid regions. The ...

Technology / Energy & Green Tech

created 5 hours ago | popularity not rated yet | comments 1


Skp2 activates cancer-promoting, glucose-processing Akt

HER2 and its epidermal growth factor receptor cousins mobilize a specialized protein to activate a major player in cancer development and sugar metabolism, scientists report in the May 25 issue of Cell.

Math predicts size of clot-forming cells

UC Davis mathematicians have helped biologists figure out why platelets, the cells that form blood clots, are the size and shape that they are. Because platelets are important both for healing wounds and in strokes and other ...

Early physical therapist treatment associated with reduced risk of healthcare utilization and reduced overall healthcare

A new study published in Spine shows that early treatment by a physical therapist for low back pain (LBP), as compared to delayed treatment, was associated with reduced risk of subsequent healthcare utilization and lower ...

Pancreatectomy OK without downstaging from therapy

(HealthDay) -- Pancreatectomy improves median survival in pancreatic cancer patients even when presurgical neoadjuvant therapy does not lead to radiographic downstaging of tumors, according to a study published ...

Flesh-Eating bacteria no cause for panic, experts say

(HealthDay) -- Despite scary headlines by the score, most people don't have to fear that they'll be the next victim of the so-called flesh-eating bacteria disease, experts say.

Of mice and mental models: Neuroscientific implications of risk-optimized behavior in the mouse

(Medical Xpress) -- Regardless of an organism’s biological complexity, every encephalized animal continuously makes under-informed behavioral choices that can have serious consequences. Despite its ubiquity, ...