Oregon State University

Sea Power

Annette Von Jouanne and Alan Wallace

The mill is silent now, and still. When International Paper succumbed to the slump in logging a few years ago and shut the doors on a plant that had once employed 650 in Gardiner and neighboring Reedsport, commerce in the coastal Oregon communities took a body blow.

The pain of the mill closure was compounded by catches of coho salmon that had been dwindling for a decade. As loggers knocked the mud off their caulk boots for the last time and fishermen let their commercial licenses lapse, families drifted away. Schools lost students. Today, Reedsport’s many boarded-up storefronts signal a community in distress.

The town sits back from the open ocean, snug against the sheltering hills of the Coast Range and wrapped inside the arc of sand that forms Winchester Bay. But out beyond the bay, past the bar, churns the constant, unceasing movement of what could someday stanch the decline of this place: Pacific Ocean waves. That’s because a team of Oregon State University researchers has been inventing devices for creating electricity — clean, renewable, low-impact energy — from the motion of the ocean. And they’ve zeroed in on Reedsport as the “sweet spot” for testing and demonstrating new technologies — in part because the old mill’s power substation, now sitting idle, could quickly be reengaged and once again buzz with electricity. Just a tiny fraction of the energy contained in the Earth’s seas — their currents, tides, waves, and heat — could power the entire planet. Tom Tymchuk is awe-struck by the statistic. “If you could harness even 1 percent of ocean energy, you could light up the world,” says the Central Lincoln Public Utility District board member, struggling to take in the enormity of that idea. “Light up the world!”

Compared to wind — the current frontrunner in renewables — waves are a lot more efficient. That’s because of what OSU electrical engineer Annette von Jouanne calls “energy density.” “Water is about 1,000 times more dense than air,” she points out. “That means you can extract more power from a smaller volume, which in turn means lower cost.” Besides, waves roll in with a lot more regularity than wind blows. Energy is available from waves upward of 80 percent of the time, compared to 45 percent or less from wind, leading to more efficient scheduling for other energy sources on the grid.

More than 20 agencies, including the Oregon and U.S. departments of energy, are backing OSU’s initiative to launch a U.S. Ocean Wave Energy Research, Development and Demonstration Center to create and test wave-power technologies. With members of Oregon’s congressional delegation strongly behind the initiative, it’s quite possible that the roar of the surf and the tang of salt spray could someday replace the kthunk-kthunk of the mill and the acrid smell of pulp as the sounds and smells of prosperity in Reedsport and other sagging economies up and down the coast.

Surviving the Tempest

The notion of extracting energy from waves is not new. When von Jouanne and her colleague, OSU electrical engineering professor Alan Wallace, began exploring the potential of wave power, their search for prior scientific writings and inventions took them into records two centuries old. As they pored over thousands of patents for turning wave energy into electricity, they pinpointed the big flaw in those earlier designs: too many moving parts. In an environment as tempestuous as the sea, moving parts require frequent maintenance and are vulnerable to breakdowns.

“To capture energy from waves, the device must be survivable, reliable, and maintainable,” says von Jouanne, a principal investigator in OSU’s wave energy research project. “In the past, there have been some failures because of the survivability issue.”

Prevailing technologies generate power by compression of a liquid (such as water) or a gas (such as air). Pumps and pistons, valves and filters, hoses and tubes, fittings and couplings and all sorts of switches, gauges, meters and sensors go into operating these systems. In contrast, with $270,000 from the National Science Foundation and a total of $60,000 in proof-of-concept grants from Oregon Sea Grant at OSU, von Jouanne and Wallace are developing technologies that work with just a handful of basic components, including an electric coil, a buoy and a magnetic shaft secured by a steel cable.

One of the OSU devices on the drawing board — which the engineers describe as a “permanent magnet linear generator” — works like this: A spiral of copper wire is secured inside a 12- by 15-foot long buoy made of an impervious composite of plastic and fiberglass. The coil surrounds a magnetic shaft, which is stationary and tetheredbouy to the ocean floor by a steel cable. As the buoy rises and falls on the waves, the coil moves up and down relative to the shaft, inducing voltage as it passes through the magnetic field. A power take-off cable carries the resulting electric current about 100 feet down to the seafloor where another cable takes the power generated by many buoys to an onshore substation.

One buoy is projected to generate 100 kilowatts of power, on average. A network of about 500 such buoys could power downtown Portland. Moreover, wave parks could address the state’s energy imbalance. West of the Cascades, Oregon consumes about 1,000 megawatts more than it generates. By tapping about 5 percent of the coastline, wave energy could make up the difference, and no new transmission lines would be needed.

The engineers’ goal is to produce a device that is lean and streamlined, designed to withstand gale-force winds, monster storms and the vagaries of sea life, from rafts of floating bull kelp to colonies of seals looking for a place to haul out. The engineers are now working on their fourth and fifth prototypes. They call their simplified approach to energy conversion “direct drive.” The fishermen just call it common sense. As one lifelong Oregon fisherman, Terry Thompson, puts it, “There’s a rule of working in the ocean that fishermen use that goes, ‘Keep it simple, stupid.’”

Wallace and von Jouanne agree. “Simplicity is the essence of it,” Wallace says. However, embedded in their design is a great deal of engineered precision. The magnetic shafts are made of a steel alloy that creates an exceptionally strong force field. The highly conductive “air-gap” coils are made of solid copper instead of the more common combination of copper and steel used in generator armatures. Thus, the conversion of mechanical motion (waves) into electrical energy can take place with great efficiency and efficacy.

The engineers develop their prototypes in OSU’s Motor Systems Resource Facility, the highest-power motor and drives testing lab at any U.S. university, and test them across campus in the O.H. Hinsdale Wave Research Laboratory, which boasts a 342-foot flume. But it will be in Reedsport that the wave-energy buoys meet their real test: the Pacific Ocean.

Of all the waves washing across the planet, Oregon’s are optimal for extracting energy, according to a study by the Palo Alto, California-based Electric Power Research Institute (EPRI). That’s because on the West Coast, the trade winds blow strong and steady, and the seafloor is a long, gentle slope, a configuration that lends itself to good wave action. And then there’s the old mill just north of Reedsport. In addition to its 50-megawatt electrical substation, it has an outflow pipe stretching 3,000 feet into the ocean — a ready-made conduit for the subsea power cable bringing electricity back to shore.

Von Jouanne and Wallace have been working closely with Justin Klure of the Oregon Department of Energy to promote the Reedsport/Gardiner area as an optimal location for the nation’s first commercial wave park. Several developers have stepped forward with the first planned phases in the 20- to 30-megawatt range. Manufacturing and fabrication would be performed locally, meaning job opportunities for coastal Oregonians. At about one to three miles offshore, the park will be invisible from the beach, thus preserving views, but close enough to make anchoring and transmission feasible.

Read more on this story at Terra Magazine

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