Will Oceans Be Our Best Source of Clean Power?

The resource is clean, renewable and vast. In fact, it covers 70 percent of the planet. That would be the ocean, with endless waves and ceaseless tides that can be harnessed to create electricity with zero carbon or particulate emissions. If logistical, environmental and efficiency challenges can be overcome -- a big "if" -- this could be a major clean energy source for the half of the world's population who live within 50 miles of coasts.

So far wave and tidal power have not been tapped on a commercial scale, but a number of pilot projects are underway worldwide and so far the prospects seem relatively promising.

This summer the world's first commercial offshore wave power project was launched off the coast of Portugal. The Agucadora Wave Park consists of three 142-meter-long hinged steel tubes called Pelamis machines. As waves move along the tubes, they move up and down and hydraulic devices at the joints generate electricity. The project plans call for 25 Pelamis machines generating up to 21 megawatts of power, which would save 60,000 tons of carbon emissions per year compared to a fossil fuel plant making the same amount of energy.

Meanwhile a commercial shore-based wave energy project was also launched in Islay, Scotland. The LIMPET, or Land Installed Marine Powered Energy Transformer, is attached to the shore and uses the waves' momentum to funnel air into turbines to produce electricity. Plans are also in the works for a 40-turbine, four megawatt wave project in Scotland's Siadar Bay which could provide electricity for a fifth of Scotland's population.

Australia, England and Israel are among other countries where the government and private companies are actively pursuing wave power.

As with other renewable energy methods the US is lagging behind Europe, but there are a number of wave power projects in the works off the west coast. In September Oregon State University's Hatfield Center and the University of Washington secured a $6.25 million, five-year grant from the Department of Energy for wave energy development including an experimental project involving large energy-generating buoys about 12 miles off Newport, Ore.

"It's very much an emerging technology," said Roger Bedard, head of ocean power for the Electric Power Research Institute, the research and development arm of the utility industry. "I am not ready to say whether the US or the world should add wave power to the portfolio of energy options. What are the effects on sedimentation, fish, marine mammals, whales migrating from Alaska to Baja? First we need to do pilot testing and get hardware in the water to answer these questions."

Bedard said there are currently about 40 device developers in various stages of development. About six are doing full scale prototype testing, he said, and about 25 more have done subscale testing in the ocean. Others are still testing devices in wave tanks.

In December 2007 the Federal Energy Regulatory Committee (FERC) issued its first permit for a hydrokinetic wave energy project in the U.S., the Makah Bay Offshore Wave Pilot Project which calls for four floating buoys and an underwater transmission cable two miles off the coast of Washington state. It is being developed by the company Finavera Renewables Ocean Energy and expected to power 150 homes. But Bedard said it still needs permits from multiple government agencies, a lengthy and costly process, to proceed.

"Unfortunately in this country the regulators want to know what the environmental effects are before we put it in the water, but we need to do pilot tests in the water to know," he said. "It's a catch 22." In 2008, FERC permit applications for wave energy projects were filed by Pacific Gas & Electric in Mendocino and Humboldt County, Calif.; and by other private companies in California and Oregon. "PG&E has all the coast of California with good strong waves as their territory," said Bedard. "They're the one utility that can really capitalize in a big way in the future in wave energy."