U.K.-based Marine Current Turbines on Wednesday announced the installation of what it claims is the world's largest tidal turbine (see Green Light post).

The 1.2-megawatt turbine will be tested for 12 weeks before feeding power into the Northern Ireland grid, the company said.

The news comes just two days after Ocean Power Technologies said it had signed an agreement to team up with Griffin Energy to develop a wave-power system off the coast of Western Australia, Thomson Financial reported. And it comes the same week Hydro Tasmania and Biopower Systems announced they would install two 250-kilowatt water-energy prototypes in Australia - one wave-power system off King Island and one tidal-power system off Flinders Island, according to The Age.

After the testing period, Marine Current expects its system to operate for up to 20 hours per day, producing enough electricity to power 1,000 average homes. If everything goes as planned, that capacity will make this project the largest tidal-stream project in the world, the company said, four times larger than the company's previous Seaflow system, installed in England's Devon County in 2003.

But the testing process is not an irrelevant hurdle.

Take Finavera Renewables as an example. The company in October watched its wave-energy test buoy sink off the shores of the central Oregon Coast only a day before the test was scheduled to end (see Pulling Energy From the Sea).

Even though the buoy produced energy as expected, the rough reality of the marine environment has proven difficult to protect against, especially as companies attempt to remain cost-effective.

Still, interest is picking up, and the United States also hopes to get in on the marine action. The Pacific Gas and Electric Co., a California utility, in December signed the first commercial wave-energy contract in the country - a deal to buy 4,000 megawatt-hours of energy annually from Finavera starting in 2010 (see Wave Energy Finds a Buyer).

Earlier this month, the U.S. Department of Energy announced it is offering up to $7.5 million in grants for hydrokinetic energy such as wave and tidal power (see Funding Roundup: Greentech Bucks Overall Investment Trend).

The department is seeking partnerships with companies and universities to develop the technologies and plans to award up to 17 grants. Applications, found at Grants.gov, are due June 16.

"Water covers more than 70 percent of the Earth's surface," said Andy Karsner, assistant secretary for energy efficiency and renewable energy at the DOE, in a written statement.

"Using environmentally responsible technologies, we have a tremendous opportunity to harness energy produced from ocean waves, tides or ocean currents, free-flowing water in rivers and other water resources to advance the administration's comprehensive energy strategy and provide clean and reliable power in the United States."

On Tuesday, Ireland-based wave-energy company Wavebob also said it plans to open a U.S. office in Annapolis, Md., according to the Baltimore Sun, which added that the company plans to test its technology on the West Coast.