Every now and then, you’ll hear about a new wave energy project, and if you’re like me, your reaction is probably, “Waves, energy, that sounds cool.” But then I wonder, if wave power is so cool, how come it’s not being implemented more widely? Maybe you’ve wondered that as well. If so, here’s your wave power cheat sheet.

There are a bunch of different designs, but they all operate on the same fundamental principle: Waves move things (up and down, back and forth). Any time you have movement, you can convert that movement into a movement that can turn a turbine. And when you can turn a turbine, you can create energy.

Tidal and current energy — the energy harnessed from the ocean’s tides and currents. They all get lumped under the moniker “ocean-generated power,” but each uses different equipment and have different pro’s and con’s.

Waves are hundreds of times more powerful than wind. Plus, they’re much more predictable. In theory, wave power could supply up to 10 percent of the United States’ energy needs

The ocean is a violent beast. It has sunk wave power equipment, broken off turbine blades, and severed moorings. “The ocean has eaten alive the machines we've put up against it," the director of the Sierra Club’s global warming program told the San Francisco Chronicle last year. Add to that the ocean’s long-term corrosive effect on any piece of machinery that takes up residence in its briny waters, plus the difficulty of storing and moving power from the ocean back to land, and the cost of building wave-energy systems goes through the roof. Currently, power generated from waves is significantly more expensive than that from solar or wind. As if that weren’t enough, there are unresolved ecological concerns. It’s not yet clear what the long-term impacts of wave energy systems will be on surrounding marine life.

Investor money is what ultimately determines whether a technology moves forward or not, and so far investors have not been keen on wave power because the economics currently don’t work out. All of which means a lot of the technology is still in its infancy, with no immediate prospects for growing significantly in the near future. Still, large companies like General Electric and Chevron that are searching for renewable energy sources have been poking around. And this year, the U.S. Department of Energy made its first grants for wave power research since 1992.

The first commercial wave farm went on line off the coast of Portugal in September. And in the U.S., Pacific Gas & Electric is building a wave farm off the California coast, which is set to become operational in 2012. Other than that, there are few significant commercial wave energy ventures.

The Economist: “The Coming Wave”

The New York Times: “Power from the Restless Sea”

CNET Green Tech: “Wave and Tidal Power Looks for Its Footing”

Image courtesy of Finavera