Wave Energy: Tapping Into the Source

The approach of winter brings the return of northwest swells to once more wrap local point breaks and pound shorelines. With the changing season come Pacific storms sending wave trains barreling into the coastline in a timeless display of natural power. As the waves crash ashore, the energy from these distant storms meets its end grinding the edge of the continent into cobblestones and sand like crumbs from a cookie. Yet, apart from providing a fleeting ride for an occasional surfer, pelican, or dolphin the power of waves has largely gone unused. This is now rapidly changing. One day ocean swells will not only make local surf breaks come to life, but their untapped energy may power the lights at home, too.

The quest to make electricity using waves stretches back well over one hundred years in California. From about 1870 through 1910 a number of individuals and companies tried to harness the ocean. Several patents went to San Franciscans for wave powered contraptions and outfits sprang up like Hercules Wave Motor Company and Pacific Wave Motor Company. Newspapers and magazines chronicled the events with headlines such as “Power from Waves” and “Unlimited Electric Power.” The San Francisco News Letter ran a story about a wave motor that produced “electric energy for illuminating the streets.” Similar experiments took place along the south coast as well, but most inventions ended in failure. With little success after years of effort interest waned with the rise of coal and oil powered machines.

A century later a resurgent interest in wave energy has been ushered in amidst an atmosphere of heightened environmental awareness. In September, Oregon State University in collaboration with Columbia Power Technologies completed a successful test of a wave energy buoy off the Oregon coast. “The buoy is a point absorber design, which basically means it’s just a buoy that bobs up and down,” said Dr. Ted Brekken, the co-director of the Wallace Energy Systems and Renewables Facility at OSU.

Inside the buoy contains a vertical metal spar coiled in copper. Surrounding this spar a float with magnets rises and falls with each passing swell. “It works pretty much exactly the same way as those shake flashlights; it’s identically the same principal,” he said. “You have a magnet moving past a copper coil generating electricity.” The electricity would then be carried to shore through transmission lines along the seafloor. Development of these buoys for full scale utility use is underway and may be supplying electricity in as little as two years.

Waves transmit more energy than wind because water is denser than air. “The power density is maybe 100 times greater,” Dr. Brekken said. This translates into the need for less ocean space to produce the same amount of electricity a larger land based wind park generates. “The area taken up by a wave park is pretty darn small compared to the overall coastal waters it would be located in,” he said. This leaves the vast majority of coastal waters untouched.

With 70 percent of the world’s surface covered by ocean a remarkable opportunity exists. According to OSU, capturing a mere 0.2 percent of ocean energy could power the world. The wave energy off American coasts can provide as much electricity as the nation’s hydroelectric plants. “Full scale of the wave resource is about the same as the hydro resource, which is approximately six percent,” Dr. Brekken said. “The resource will be fully developed when there is five to seven wave parks with each of those generating over 100 megawatts,” he said. That amount of electricity could power several hundred thousand homes. Attracted by this untapped potential, and driven in part by the fervor surrounding environmental concerns for emission free energy production, broad based support has emerged. The U.S. Department of Energy awarded a $1.25 million grant to OSU this year alone. State governments on the Pacific seaboard are also involved.

Companies like Finavera Renewables are riding the wave of public support for clean energy. They signed the nation’s first power purchase agreement for wave generated electricity with PG&E. The Humboldt County Offshore Wave Energy Power Plant is slated to provide electricity by 2012 from buoys moored 2.5 miles offshore. “For pthe two megawatt project we’re looking at eight devices,” said Myke Clark, a senior vice president with Finavera. The company’s wave energy conversion device, the AquabuOY 2.0, is entirely wave powered. “It’s relatively simple,” he said. “That’s definitely what we like about the technology. The hydraulic fluid is just pressurized seawater so there are no hydraulic oils on board.” The main elements are the buoy, acceleration tube, piston, and hose pump. Seawater enters the buoy with the rise and fall of each passing swell powering a two-stroke hose pump that pressurizes the water. The water is then forced through a turbine that powers a generator to produce electricity.

The device’s simplicity lessens concerns about pollution in the event of its failure. “In catastrophic circumstances,” he explained, “if it happens to go down there is almost no environmental impact.” Finavera confirmed this when their prototype sank last fall. “It sat on the ocean floor for almost nine months and there was no impact.” Despite the setback the power generating mechanics of the buoy worked. Finavera is currently developing the next generation of AquabuOy.

Certain ocean conditions are better than others. During the summer the buoy generates less electricity than the winter storm season. “The device can work in a variety of conditions, but winter is best and produces significantly higher output,” Mr. Clark said. Although in exceptionally rough conditions the buoy would be temporarily inactive. “In huge massive storms,” he noted, “there is going to be shut off; at a certain level they wouldn’t be operating.”

Waves may provide a clean source of electricity, but environmental concerns still exist. Electromagnetic fields around buoys may interfere with marine mammal and fish sensory systems. Possible physical effects from buoy placement and underwater transmission lines may alter local wave patterns, currents, and beaches. Other problems also remain unknown. Not only will wave parks impact sea life, but coastal communities, too. Alliances have formed to speak up for local interests. While cooperation in Oregon among the university, energy companies, and community stakeholders has been strong, argument has arisen in California.

Fishermen Interested in Safe Hydrokinetics (FISH) is a coalition of stakeholders in Fort Bragg formed in response to proposed wave parks in Mendocino County waters. The alliance includes groups like the Recreational Fishing Alliance, Salmon Restoration Association, and Sonoma County Abalone Network. FISH opposes the hasty issuance of permits by the Federal Energy Regulatory Committee (FERC), which granted a permit to PG&E to begin preliminary studies assessing the feasibility of wave parks. According to the coordinator of FISH, Jim Martin, there is widespread “suspicion” in his community toward FERC and PG&E. “They refuse to grant us a seat at the table,” he said. At the same time Fort Bragg City Council and Mendocino County have filed lawsuits against FERC in federal court. The opposition is based, in part, on concerns about potential adverse effects from wave parks that will directly impact port communities.

“One of our major concerns is loss of access,” Mr. Martin said. Portions of ocean are slated to be cordoned off for wave parks, but lost access isn’t the only issue. These projects may impact an area beyond where a particular group of buoys is moored. “We do not know that it is safe for fish,” observed Mr. Martin. With their commercial livelihood and recreational interests on the line, the alliance insists on a thorough assessment of the technology’s safety. “One thing we’re not negotiable about,” he made clear, “is the need for adequate environmental review and analysis of potential impacts to marine ecosystems.” Considering much of the support behind wave energy is based on environmental concerns it’s an ironic demand to have to make. “We’re interested in safe renewable energy that respects existing sustainable use of the ocean for fishermen, divers, surfers, and the rest of the public,” Mr. Martin said.

The Central Coast may be in for a similar experience. Green Wave Energy Solutions applied to FERC for a permit earlier this year. The Thousand Oaks based company hopes to stake out a 17 square mile patch of ocean off Morro Bay to Point Buchon to carry out preliminary studies. With at least 12 different projects currently being discussed for the Pacific coast wave parks will eventually be installed somewhere. As Myke Clark notes about Finavera’s contract with PG&E, “We have to deliver the electricity by the end of 2012.” Wave parks render a particular area of ocean inaccessible so it’s crucial people get involved to speak up on behalf of coastal communities. And while FERC may be frustrating some locals companies like Finavera are more engaged. “We really think communities have to be partners in a project. We get out and really canvass the local stakeholders,” Mr. Clark said.

The ocean remains the greatest pool of untapped renewable energy on the planet. The push is on to capture this homegrown source of clean power and there are lots of players in the game. Corporations, universities, state, and federal government and community based organizations. While the wave energy industry remains in an emergent state, the level of enthusiasm pushing it forward will likely ensure its long-term success. It’s possible to make electricity from waves. It now remains to create devices capable of supplying large population centers and weave through the obstacle course of competing interests to get them installed. It will take broad based cooperation, but within sight is an opportunity to help wean ourselves from other pollution ridden sources of electricity.

Published in print in the November 2008 issue of Deep Magazine. Archived online at deepzine.com.

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