Thursday, April 23, 2009

Oregon's Power Potential (4/8) Wave & Tidal

Wave Power / Tidal
The Oregon wave power projects convert the Pacific Ocean's heavy rolling swell into renewable energy. Buoys harness the near constant rise and fall of waves.

One type of power buoy, is tethered to the ocean floor so the buoy shaft remains fixed in place, as the outer section bobs up and down in the water. That motion, coupled with magnets and copper coil, generates electricity. Another type is a long snake type. The waves flex the snake and the joints generate electricity. These are being used in Portugal. The ominously named Wave Dragon type has long arms that extend out to concentrate wave energy were the water can be dropped through a turbine much like a hydroelectric dam. These are currently being used in Norway. One tidal type is a man-made blowhole that forces air through a turbine. These are currently being used in Scottland.

Oregon's spectacular coastline could become the United States' center for wave energy development. Two demo projects are underway. If expanded, wave power could generate much of the state's future energy needs.

Wave harnessing was proposed in the August 1932 edition of Modern Mechanix. Globally, wave energy is now undergoing a revival not seen since the OPEC energy crisis of the 1970s. At that time, ocean energy (wave and tidal) enjoyed a brief period of attention, as oil supplies slumped and the price of crude skyrocketed. However, interest waned as prices for fossil fuels dropped and incentives to develop alternative energy supplies evaporated. "Wave energy is still in its infancy," said Justin Klure, a senior energy advisor for Oregon Department of Energy. "In order for ocean energy resources to be viable, advances need to be made in the technology and wave energy must be made affordable to consumers.”

Due to the prevailing winds, waves are more powerful on the west coast of the continent. Along Oregon's 460 kilometers of open coastline, waves average 1.5 meters high during the summer months and 3.5 meters during the winter. This makes Oregon an ideal location for wave power. Electrical engineers at Oregon State University (OSU) are developing buoys that can withstand the elements and that they believe will be a key component in affordable clean power. With the development of OSU prototypes and plans for a wave farm near Gardiner some hope our state becomes the center for this nascent industry.

The Oregon coast's paucity of sunshine also makes wave technology appealing to state regulators. When compared to wind and solar power, waves are more consistent. Water is 800 times denser than air so the amount of energy extractable from ocean power is an order of magnitude greater. Some wave proponents claim that harnessing just 0.2 percent of the ocean's energy would meet the entire planet's power needs. Just the with the extraordinary solar claims, this is likely a theoretical statement that ignores many of the real problems of collecting and transmitting the energy, but it does make the point that there is a massive untapped potential.

Incoming swell can be predicted with 80 percent accuracy. A modest sized plant of 200 buoys could illuminate all of downtown Portland. Clearly there is an opportunity for Oregon here.

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