Wave Power Could Revolutionize Renewable-Energy

There's enough wave energy in the oceans to power the world, and scientists are finally close to harnessing it. 

The wave-power revolution has quietly and gradually gained momentum. The Department of Energy announced it would allocate as much as $40 million in funding to develop of the nation’s first open-water wave-energy-testing facility in a location to be determined.

When it comes to tapping the commercial viability of this renewable resource, we could be on the cusp of a tidal change. For decades wave energy has lagged behind wind energy  and solar, in part because harnessing it is so complex.

It involves a number of factors — the speed, height, direction of a swell and the intervals between swells — and more variables equal higher costs.

Additionally, harnessing wave power involves installing costly equipment in a corrosive and treacherous environment.

Then there’s the challenge of transmitting that energy from offshore to the power grid.

These realities have scared away many would-be investors. Regulatory hurdles have put off others: In 2008, what would have been the first commercial wave-energy project in the country was nixed by California’s Public Utilities Commission, which said the technology was too new to be trusted.

The potential is so huge: A report from the Intergovernmental Panel on Climate Change suggests the power-generating potential of the world’s oceans exceeds human energy requirements. Imagine no need for  coal, fossil fuels, nuclear generators, solar arrays or wind turbines — and no need to rely on overseas suppliers.

According to the U.S. Department of Energy, waves along American coastlines have the potential to generate as much 2,640 terrawatt hours a year — enough to power more than 200 million American households, free of emissions.

Waves are more consistent and predictable than either solar or wind power, meaning it will be easier to plan the integration of wave energy into a power grid. They also pack a bigger punch. Water moving at 12 miles a hour (normal for a standard day at the beach) offers the same power potential as wind moving at 110 miles per hour (not so standard for a day anywhere).

The Scottish-built Pelamis, the world’s first commercial wave farm, launched off the coast of Portugal in 2008. The system, which consisted of four caterpillar-like converters spanning a total of more than 1,500 feet, began supplying 1,500 homes with clean electricity but was shut down after two months due to frequent breakdowns and financial struggles.

The U.S. Navy-sponsored Azura system, however, currently powering a Marine Corps base near Hawaii’s Kaneohe Bay on the north shore of Oahu has been successfully tapping the ocean’s power supply for a year. The 45-ton floating device rotates 360 degrees and, unlike many other wave converters, is able to extract power from both the horizontal and vertical motions of the waves. Since March of last year a larger implementation, the first wave farm consisting of multiple units, has been making headlines in Australia. 

Source: Salon

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Taxonomy

• Energy
• Wave Energy
• Water