Friday, August 1, 2008

Tide is slowly rising in interest in ocean power

By Efrain Viscarolasaga

Renewable energy analysts suspect the world’s ocean waves could provide two terawatts of electricity per year — about one-seventh of the estimated world energy consumption in 2007 — yet unlike wind turbines and photovoltaics, the technology for converting that potential into electricity is still in its infancy.

With the renewable energy race on, however, there is no shortage of new ideas for making ocean power economically and logistically viable.

“The industry is like a big funnel right now,” said Roger Bedard, head of the ocean energy department of the Electric Power Research Institute in Palo Alto, California. “There are hundreds, if not thousands, of ideas on the top, but very few that are in the prototype stage, and even less that have been tested in the water.”

New England boasts several of those companies that are moving closer and closer to commercialization, each looking at its own different twist to the technology.

With a real-water test in Maine completed over the winter, Fall River-based tidal power developer Ocean Renewable Power Co. LLC is the furthest along in terms of deployment, and also believed to be the only local company looking at tidal power, which uses the daily motion of the tides to generate power. While the technology has proven functional, its application is limited to areas with drastic tidal changes, located in higher latitudes, such as Maine and Oregon.

Bristol, R.I.-based Ocean Wave Energy Co. and Watertown, Mass.-based Resolute Marine Energy Inc., on the other hand, are working on exploiting the undulation of waves to generate power. Ocean Wave Energy’s design uses three buoys in a single module that rise and fall in a piston-like motion to generate power. While the company has gone through several different versions of its technology, the premise is based on patents awarded to founder Foerd Ames in 1980.

Resolute was founded last year and is still in its earliest stages. CEO William Staby would not disclose the details of his firm’s technology, but said it is based on “point absorber” designs, which uses a piston-like motion similar to that used by Ocean Wave Energy, but in a single buoy unit.

While grid-connected power is the main goal for ocean power in general, both Resolute and Ocean Wave Energy are eyeing smaller applications in the near term. Resolute intends to apply the technology to offshore facilities, such as those in the exploration and aquaculture industries.

Ames, on the other hand, said his technology can be used to power offshore hydrogen generation through electrolysis or water desalinization.

While each company uses different approaches, the common thread — and primary reason ocean power has yet to penetrate the public alternative energy consciousness — is the challenge of working in the harsh marine environment.

“The key hurdle here is, can they survive in the rough environment in which they will have to operate?” said Staby. “And the next question is, can you build a survivable product cost-effectively?”

While industry insiders are bullish on the future of wave and tidal power, progress is coming slowly. At this time, there are no commercial-sized deployments for wave power operating in the world, though tests like Ocean Renewable Power’s in Maine and several in the United Kingdom are moving the industry forward.

“The energy density of the ocean is much more significant than solar or wind, and that makes it actually cheaper to deploy,” said Bedard. “It’s the operation, installation and maintenance costs that are still unknown.”