|US wave energy resources. Click to enlarge. Source: EPRI|
Finavera Renewables Inc. has deployed and commissioned the AquaBuOY 2.0 wave energy converter off the coast of Newport, Oregon. This marks the first installation of a wave energy converter of this scale off the west coast of North America and moves the company closer to achieving its goal of commercial electricity generation from ocean waves by 2010.
The total incident wave energy flux into the US is approximately 2,100 TWh/yr—about 50% of the total electricity generation in the US in 2006 of 4,254 TWh (BP Stat Review 2007)—and is thus a significant potential resource, according to a 2004 assessment by EPRI, the Electric Power Research Institute.
|Annual average wave energy flux per unit width of wave crest (kW/m). Click to enlarge. Source: Finavera|
The AquaBuOY is a floating buoy structure that converts the kinetic energy of the vertical motion of oncoming waves into electricity. The AquaBuOY is categorized as a point absorber—having a small dimension in relation to the longer wave length in which it is operating. It utilizes a cylindrical buoy as the displacer and the reactor is a large water mass enclosed by a long vertical tube underneath the buoy.
Other wave energy conversion technologies include oscillating water column, overtopping, and attenuator systems.
The AquaBuOY Consists of four elements: buoy; acceleration tube; piston; and hose pump. The acceleration tube, the piston, and the hose pumps constitute the Power Take Off system (PTO).
Movement of the piston within the hollow, open acceleration tube extends or compresses the hose-pumps. A hose-pump is a steel reinforced rubber hose whose internal volume is reduced when the hose is stretched, thereby acting as a pump. Pressurized sea water is expelled into a high-pressure accumulator, and in turn fed to a turbine which drives a generator.
The AquaBuOY 2.0 is situated approximately two and a half miles off the coast of Newport, Oregon. Over the next several weeks, Finavera Renewables will test and analyze the performance of the components and monitor the hydraulic power output. During this phase, all onboard diagnostic equipment will be powered by an onboard Pelton turbine as well as solar panels and small wind turbines installed on the device. Data is being streamed live via wireless and satellite technology for analysis. This test data will be used for the next design iteration of the wave energy converter, with an anticipated deployment in 2008.
The Company is advancing along its project development plan with the phased installation of a multi-device wave park and commercial electricity generation by 2010. The Company currently has wave energy projects totaling more than 250 megawatts (MW) planned or under development on the west coast of North America.