SWEDISH UTILITY GIANT DIVES INTO WAVES

Vattenfall has high hopes for wave power
February 1, 2010 (UPI)

"Swedish energy giant Vattenfall says ocean energy -- such as wave power, salinity power or power from sea currents -- will become commercially viable as early as 2020.

"The Swedes place their hopes in wave power, which they estimate could account for up 10 percent of Vattenfall's power generation in 2030…Vattenfall says it can ultimately produce around 250 TWh of green power, enough to supply up to 40 million people…However, wave power is still an immature technology. Vattenfall is researching three different concepts -- Seabased, Wavebob and Pelamis."

Sweden's Seabased wave energy device, waiting to go to sea. (click to enlarge)

"The device developed by Swedish company Seabased has been tested since August 2009 off the Norwegian coast. The wave power facility is made up of several small buoys floating on the ocean surface that are linked via power cables to linear generators anchored to the seabed…

"Wavebob is…a similar but much larger device…made up of two buoys, one floating on, and the other below the water surface…[T]he motion between the two buoys…acts on hydraulic pistons that in turn pump oil to drive generators…Each device is around 60 feet in diameter and nearly 300 feet high, and has a power output of around 1.5 MW…[Wavebob] automatically adjusts its response to suit the prevailing wave climate and thus maximizes its power generation capacity…[making] wave power more efficient, cheaper, easier to maintain and environmentally less intrusive…The project is supported by the Irish government, which…[expects] to create 120,000 green jobs over the next few years."

Schematic of how the Seabased device works. (click to enlarge)

"An even larger device is the Pelamis, to be tested later this year off the Scottish coast. The 450-foot Pelamis looks a bit like a giant steel snake floating on the water. It rides the waves parallel to their direction and absorbs energy by restricting the motion of the bodies relative to each other by hydraulic rams.

"All three concepts face…harsh seas with a minimum of maintenance…[and minimizing] economic impact on marine animals… to become commercially viable…Ireland and Scotland, two countries with great wave power potentials, have indicated that they would be willing to subsidize this new technology…Vattenfall says it wants to have a large-scale demo site online by 2015 and make the technology commercially feasibly by 2020…"