WAVE ENERGY RISING

Wave energy current cost: ~45-50 cents/kilowatt-hour (10 times the price of fossil fuel electricity). But there has been almost no commercial-sized activity and no mass production. The price is expected to fall fast with economies of scale, making wave energy ready for the marketplace.

Whatever Happened to Wave Energy?
Michael Schirber, October 29, 2007 (LiveScience via Yahoo News)

WHO
Andrew Parish, CEO, Wavebob Ltd.; Carolyn Elefant, CEO, Ocean Renewable Energy Coalition;

WHAT
The harsh ocean environment and the hard motion of ocean waves represent serious challenges for wave energy developers.

Wavebob (click to enlarge)

WHEN
- The ocean surface is almost always moving, so wave energy is not intermittent. The fluctuations in ocean movement are relatively predictable.
- The 1st farm is almost running off Portugal.
- A wavebob prototype began making electricity in October off Galway in Ireland. Wavebob engineers plan to launch a full-scale, 1.3 megawatt prototype in 2009.

WHERE
- Some 90 wave energy concepts are on record but most are only on paper.
- Ocean energy is located near population centers.
- Test projects are up and running in Europe.

WHY
- Computer modeling now allows for substantial testing.
- US wave energy potential estimate: 250 million megawatt-hours/year, 6.5% of US electricity need.
Development has been slow due to regulatory complications and lack of incentives.
- Wavebob concept is called a single point absorber and is especially effective and adaptive in harsh ocean environments: a buoy-like device w/two free-floating parts: a light, donut-shaped body bobs on the surface linked by a shaft to a heavier part deep below the surface. The relative motion drives a piston makes electricity.
- Portugal wave farm: 3 Pelamis floating attenuator devices. 400 ft long, bending/flexing snake-like segments work hydraulic pumps that generate electricity.
- Oscillating water columns funnel water into chambers forcing trapped air up to drive a turbine.
- Overtopping devices capture the cresting wave’s force and channel its flow.

Schematic representation of the "bobbing" part at the water's surface and the fixed section deep below. (click to enlarge)

QUOTES
- Parrish, Wavebob: "It's a hard technology to try to develop…The sea is not the most hospitable environment…But there will not be one device that fits all ocean environments…The big challenge is to get more devices out of the bath tub and into the sea…"
- Elefant, Ocean Renewable Energy Coalition: "We are past the technological hurdles…Now the problem is just getting the projects in the water."