Energy seekers look to ocean's power

By LIDIA WASOWICZ, UPI Senior Science Writer

SAN FRANCISCO, April 20 (UPI) -- Surf's up for a research group seeking to catch the wave to a free, plentiful, Earth-friendly and never-ending source of power: the ocean.

In the next few weeks, experts from around the country will start beach-hopping along the California coast to study the feasibility of using sea swells as a potential source of renewable energy that is more constant than the wind and sun.


The aim of the project, funded by a $120,000 grant from the California Energy Commission and expected to last approximately nine months, is to determine how much ocean-based electricity could be generated along the 1,100-mile coastline of the energy-beleaguered state, to project the likely costs of such production and to identify any environmental issues tied to developing wave-to-wire systems that could help keep the lights burning.

Initial assessments indicate a potential 23,000 megawatts of electricity -- enough to meet the needs of 23 million average homes -- churn in the swells off California's northern coast alone, an appealing alternative for an environmentally conscious state rattled by rolling blackouts and sky-high spikes in utility bills.


The state utility Pacific Gas & Electric Co., taking technological and environmental constraints into account, estimated in a 1991 report that 20 percent of that power could be harvested. Now investigators want to take a closer look at the true potential from the waves.

"The overall goals of this project are to assess the ability to use ocean-wave energy resources off the California coast to provide affordable, reliable, clean and safe electricity and identify the optimal locations for developing ocean-wave energy systems," team leader Asfaw Beyene, professor of mechanical engineering at San Diego State University, told United Press International.

"To date, only small portions of the California coast have been evaluated for their ocean-wave energy potential, and there has not been an ocean-wave energy assessment for California that takes into account the relevant technical, economic and environmental considerations," Bayene said. Such considerations include the impact of marine power stations on shipping lanes, commercial fishing, sea life, water sports and area aesthetics.

The scientists are charged with pinpointing the likelihood, benefits and effects of converting the kinetic energy that drives waves into electricity that powers homes and businesses before hard-to-come-by public and private funds are invested in such a venture.

The stakes could be significant, and not just for the Golden State whose fortunes lost much of their shine with the energy-turned-fiscal crisis that persisted from mid-2000 to the summer of 2001.


"Wave energy, like wind and solar energy -- and unlike biomass energy -- is effectively nonpolluting, so I believe it should be considered in the mix of renewable energy sources to be used in California and other coastal states," Mark. Jacobson, associate professor of civil and environmental engineering at Stanford University, told UPI.

"Wind, solar, plus wave energy could supply 20 to 35 percent of California and the U.S. power needs if the American public decides this is what it wants," Jacobson said.

The political climate appears warming toward alternative sources, with the U.S. Senate Energy Committee endorsing a "renewable portfolio standard" that would require utilities to generate 5 to 10 percent of their power from solar, wind, geothermal and other forms of renewable energy, which currently comprise 1 percent of the nation's electricity mix. In its traditional ahead-of-the-pack environmental position, California is already using such resources to meet 12 percent of its energy demands, and officials have vowed to boost the figure to 17 percent by 2006.

Riding the wave to success will be no small task for ocean energy proponents. For one thing, creating machinery that fits the job description presents researchers with a formidable challenge.

"The device must be capable of gathering useful energy from a relatively calm sea with wave heights of 3 or 4 feet. It must also be able to harvest from and survive heavy seas where wave heights can routinely exceed 60 feet," Beyene said. "As a result, simplicity becomes a leading design criterion."


The idea is to capture power from the ceaseless motion of the ocean waves, a sustainable resource created as wind blows over the water's surface and preserved until reaching the coastal shallows and beaches where the energy is released. The World Energy Council estimates that the equivalent of twice the global electricity production could be harvested from the world's oceans, which cover three-quarters of the planet's surface.

A key challenge is how to make the concept competitive economically with conventional sources of energy -- electricity produced by burning coal costs approximately 2.6 cents per kilowatt-hour, about a third of the price for power from wave generators installed in the United Kingdom.

"The predicted generating costs of wave energy have been historically high, but they have decreased significantly in recent years," Beyene said. "Wave energy is now predicted to be economic in niche markets, with potential for improved economics in the future."

Decades in the making, current wave-energy-to-electricity converters fall into three basic categories:

*float or buoy systems that rely on the soar and sink of swells to drive hydraulic pumps;

*fixed oscillating water column devices that employ the in-and-out motion of shore waves to turn air-driven turbines;

*tapered channel systems that propel waves squeezed into small reservoirs to gush through turbines, in a fashion reminiscent of hydroelectric dams.


While fixed devices, mounted to the seabed or shore, offer maintenance and other advantages over floating systems, they are suited to only a limited number of available areas.

Tapered channel systems, with very few moving parts, carry the benefits of low maintenance costs and high reliability as well as power on demand, since the reservoir can store the energy until needed. But they have stringent requirements that not all coastal areas can meet: consistent waves with sufficient energy, deep water near the shore and a prime location for a reservoir.

The team's mission includes evaluating the commercial potential of existing technologies that aim to catch the waves' power.

"The resource assessment will determine approximately how much energy is available from any location off the California coast at any particular time and will provide locations in which the conditions for the different available OWEC (ocean wave energy conversion) technologies are best suited," David Navarro of the state energy commission told UPI.

Several hundred patented devices designed to operate on the shoreline, near shore or offshore are in various stages of design and deployment around the globe. None yet appears made to order.

Shoreline devices may be easier to access and maintain and have no need for deep water moorings and long underwater electrical cables, but most have been saddled with prohibitively high installation costs.


Near-shore devices stick to shallow waters, typically 33 to 83 feet deep, avoiding the building and maintenance expenses of systems situated in deeper, more distant waters. Yet that is where powerful waves are more probable and environmental conflicts less likely, experts told UPI.

Offshore generators, geared toward depths of more than 132 feet, may carry not only a higher price tag but also the added complexity of connecting them to the power grid by long transmission cables strung along the sea floor.

"The task for (the researchers) is to determine how much potential energy lies in the waves off the coast of California at any given time. The task of the OWEC companies is to make their device(s) efficient enough to be competitive with existing electricity-generating technologies, fossil or renewable," Navarro said.

"The potential is large, but the engineering hurdles, plus the cables to shore, make this unlikely to become a very large-scale energy technology," said Daniel Kammen, professor in the Energy and Resources Group and director of the Renewable and Appropriate Energy Laboratory at the University of California at Berkeley.

Kammen, who has testified as an expert before congressional hearings on energy policy, added, "But for some local applications, it can not only do well, but be an economic winner."


With uncertain cost and performance, wave energy technologies have attracted little capital in the United States since the initial surge in interest, and dollars, in the 1970s.

"A successful track record will be required prior to any substantial investment, particularly in view of the demanding environment in which these devices will operate," Beyene said.

A reversal in California's energy fortunes and a revival of interest in renewable energy sources may turn the tide in their favor, ocean energy advocates such as AquaEnergy Group Ltd. hope.

The Mercer Island, Wash., developer of wave energy converters plans to build a $2.5 million demonstration plant off Wa'atch Point in Neah Bay on Washington's northwest coast. The local utility has agreed to buy 1 megawatt of power from the project, which features one of the few offshore technologies.

In Berkeley, Calif., start-up Sea Power & Associates is trying to raise $1.2 million to install a prototype ocean wave generator driven by the rise and fall of ocean waves along the Northern California coast. The entrepreneurs got a jump-start last year when they took home the $10,000 grand prize at the Social Venture Competition sponsored by the Haas School of Business at UC Berkeley for their patented Wave Rider technology. The series of lightweight concrete floats would sit 1 to 2 miles offshore and connect to a hydraulic pump extending 60 feet to the ocean floor.


On a larger scale, countries such as Norway, Scotland, Japan, Australia and Indonesia have been forging ahead with government-backed wave energy operations. The world's first commercial marine power station, an oscillating water column system operated by ocean energy pioneer WaveGen, based in Inverness, began supplying power to the small Scottish island of Islay in November 2000.

Several other OWC designs are getting their feet wet in various coastal corners of Europe, Asia and Australia. For example, Ocean Swell Powered Renewable Energy, is an ocean-bottom-mounted plant designed to operate in 50 feet of water within a half-mile or so of shore. It is capable of generating up to 2 megawatts of power. A commercial version, OSPREY 2000, is to be deployed this year in Ireland, which enjoys one of Europe's best wave climates yet imports more than 90 percent of its energy.

The Islay plant aside, most wave energy devices remain at the research and development stage and have yet to enter the market. A number of companies, however, are poised to unveil their first commercial schemes.

British Columbia's electric utility, BC Hydro, plans to build the first wave power facility in North America. The 3-to-4-megawatt device on Vancouver Island would use an oscillating water column system developed by Energetech Australia Pty Ltd. The venture is part of a 20-megawatt Vancouver Island Green Energy Demonstration project, which will include 10 megawatts of wind power and 6 to 8 megawatts of micro-hydroelectric power by 2004. To pursue such undertakings in North and South America, Energetech has established a U.S. subsidiary, Energetech America.


Proponents hope that once these generators start proving the ocean's power, marine energy plants will become the wave of the future.

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