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Directory:Wave buoys

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Wave Buoys

Wave buoys convert the ocean or sea wave energy into electricity. The flotation portion undulates with the waves, while a shaft fixed to the sea floor provides the counter-active force from which energy can be generated.

Table of contents

How it Works

Permanent Magnet Linear Generator Buoys

Permanent Magnet Linear Generator Buoy designUniversity of Oregon
Permanent Magnet Linear Generator Buoy design
University of Oregon

"In the permanent magnet linear generator buoy, an electric coil surrounds a magnetic shaft inside the buoy, and while coil is secured directly to the buoy (see illustration), the magnetic shaft is anchored to the sea floor. When waves cause the coil to move up and down relative to the fixed magnetic shaft, voltage is induced and electricity is generated. Each buoy could potentially produce 250 kilowatts of power, and the technology can be scaled up or down to suit a variety of energy needs. A fleet of about 200 such buoys could power the business district of downtown Portland." (PhysOrg (

How Much Energy Can be Harnessed?

"Each [permanent magnet linear generator] buoy could potentially produce 250 kilowatts of power, and the technology can be scaled up or down to suit a variety of energy needs. A fleet of about 200 such buoys could power the business district of Fredericton." (PhysOrg (

Main Developers


  • Pelamis Wave Power: In the Sweet Spot of the Curl for Renewable Energy ( - The Edinburgh based Pelamis Wave Power Converter has undergone stringest testing over the past ten years before its launch into the commercial market. The project has achieved world-wide attention and created a divided base of support within Scotland. (PhysOrg; Nov. 9, 2007)
  • Ocean Power Delivery ( - The Pelamis is an offshore semi-submerged, articulated structure composed of cylindrical sections linked by hinged joints. The wave-induced motion of these joints is resisted by hydraulic rams, which pump high-pressure oil through hydraulic motors via smoothing accumulators.
  • Portugal to get world's first commercial wave farm ( - Pelamis prototype phase completed, they are now ready to commence commercial application. Energy converter is an elongated metal unit that looks like a big semi-submerged sausage, with hinged segments that rock with the sea, up and down and side to side, pumping fluid to hydraulic motors that drive generators. Three to begin; additional 30 by end of 2006, each generating a little less than 1 megawatt. (Reuters; May 20, 2005) (Thanks Slashdot (
  • Pelamis Wave Energy Converter is Launched ( - "Following six years of detailed design and development, UK-based Ocean Power Delivery has completed the build of the first full-scale Pelamis Wave Energy Converter. Similar in size and rating to a modern wind turbine the Pelamis is designed to harness the energy contained in ocean waves to produce electricity. The machine is the world's first commercial-scale floating wave energy converter." (SolarAccess; Mar. 3, 2004) (Submitted by Frank Randall)
  • Pelamis Wave Converter Improvements ( - Technology used to gather wave energy is taking some hints from the wind energy industry, and Ocean Power Delivery (OPD) is ready to move onto the next stage of investments and testing for its Pelamis Wave Energy Converter. (SolarAccess News; June 28, 2004)

Manchester Bobber

  • Manchester Bobber - The Manchester (UK) Bobber (, a patented new wave energy device, passed Phase One in January 2005, testing of 1/100th scale working model. The commercial vision is to deploy a number of platforms, each of which supports a closely spaced array of bobbing floats (between 25 and 50) that generate electricity through independent generators. Each of the generators will be rated at 500kW so a platform will be rated at approximately 12MW and will provide an average annual output of 4MW.

Ocean Power Technologies, Inc

  • - "Our PowerBuoy® system consists of a floating buoy-like device that is loosely moored to the seabed so that it can freely move up and down in response to the rising and falling of the waves, as well as a power take off device, an electrical generator, a power electronics system and our control system, all of which are sealed in the unit."
    • Ocean Power Technologies, Inc. Files Registration Statement for Initial Public Offering in US ( - Ocean Power Technologies, Inc. (“OPT��? or the “Company��?) announced today that it has filed a registration statement with the Securities and Exchange Commission to register up to $100 million in shares for a proposed public offering of the Company’s common stock in the United States. All shares of the common stock to be sold in the offering will be sold by Ocean Power Technologies, Inc. (BusinessWire; November 13, 2006)

Aqua Buoy / WaveBuOY

  • AquaBuOY based on long-proven technology - The AquaBuOY technology, which has been independently evaluated and found commercially viable, has potential to generate electricity at a cost that is competitive with onshore and offshore wind farms and some fossil fuels, in the near to mid-term.
  • Wave buoys - Convert the ocean or sea wave energy into electricity. The flotation portion undulates with the waves, while a shaft fixed to the sea floor provides the counter-active force from which energy can be generated.


  • US Congress told of 'Huge Potential' of Ocean Wave Energy ( - Finavera Renewables Inc. CEO outlined his vision for the advancement of the United States ocean energy industry before a US Congress committee. (BusinessWire; Apr. 25, 2007)

Oregon State University

Permanent Magnet Linear Generator Buoy sketch source (
Permanent Magnet Linear Generator Buoy sketch
source (

Team led by Annette von Jouanne and Alan Wallace

"With this type of system, it would be possible to crank the buoy beneath the ocean surface to survive severe storm conditions or tsunamis." (source (
"Oregon State University's proximity to the Pacific coast combined with strategic research facilities in the OSU Motor Systems Resource Facility and the O.H. Hinsdale Wave Research Laboratory make it a leader in this new technology. The researchers are planning a demonstration facility to test this developing technology in conjunction with the Electric Power Research Institute and others." (PhysOrg (

Other Buoy Systems

  • Wave Dragon ( - Wave Dragon is a floating, slack-moored energy converter of the overtopping type that can be deployed in a single unit or in arrays of Wave Dragon units up to 200 resulting in a power plant with a capacity comparable to traditional fossil fuel based power plants. YouTube (
  • ABB ( - The WEC ( device developed by Fred Olsen Ltd ( looks like a traditional rig with floating, egg-shaped cylinders hanging underneath it, that absorb energy from the waves as they move up and down. This linear, vertical motion is then converted to rotational motion by means of a hydraulic system – a hydraulic motor drives a generator to produce electricity.
  • Wave Hub ( - Renewable energy project in the South West of England that aims to create the UK's first offshore facility for the demonstration and proving of the operation of arrays of wave energy generation devices.
  • SeaVolt Technologies ( - Wave Rider consists of a special buoy that bobs up and down with wave action on the ocean surface. A hydraulic circuit captures the slow rolling energy of the wave and converts it into high-pressure hydraulic fluid flow, spinning a turbine to generate electricity.
  • Ocean Motion International ( - The OMI WavePump uses a buoyant vessel which rides on the wave surface. The bottom hull is flooded and descends to the ocean floor to become the footing. When a trough passes beneath the buoyant vessel, a heavy ballast mass descends and pressurizes the water in several sleeve type pumps.
  • Ocean Power Technologies, Inc. ( - OPT is the leader in cost-effective, advanced, and environmentally sound offshore wave power technology. The electrical power generated by OPT's technology is key to meeting the energy needs of utilities, independent power producers and the public sector. OPT's PowerBuoy™ system extracts the natural energy in ocean waves, and is based on the integration of patented technologies in hydrodynamics, electronics, conversion mechanics, and computer control systems.
  • OWECO Ocean Wave Energy Company ( - OWEC Ocean Wave Energy Converter consists of floating buoys attached to a submerged buoy. Relative movement between the buoys from wave motion move linear electrical generators up and down within tubes. An array of modules can be interconnected to form an energy web.
  • Trident Energy ( - The Direct Energy Conversion Method uses floats placed in the sea that drive 80% efficient linear generators, resulting in the immediate generation of electricity. The DECM is the simplest marine renewable energy generation system that exists, is self protecting and does not depend on the use of hydraulics.
  • Independent Natural Resources ( - The SEADOG™ pump is a "point absorbing" wave energy converter that primarily uses buoyancy as a means of converting wave energy to mechanical energy by utilizing a moving volume of water to pump gas, liquid and combinations thereof. The mechanical energy generated by the pump can be converted to electricity or used for purposes of providing potable water, aquaculture habitats, and pressurized air for multiple applications such as cooling and running turbines or equipment.
  • Rothman Energy Systems ( - The Wave Energy Machine is inexpensive, flexible and scalable, based on a truss anchored to a pivot point on shore, with a float device attached over water. The wave motion provides a "teeter-totter" effect which is translated into useable mechanical energy through a connector rod attached to a cam assembly.
  • Lancaster University ( - The PS Frog is a floating offshore wave energy converter that is designed to extract power from the Pitching and Surging (PS) motion, applying a reaction to an internal mass which slides along runners at the top of the device.
  • Brandl Motor ( - A floating disc rises and falls with the waves, while a pendulum mass hanging beneath a spring moves anticyclical up and down, driving direct-connected magnets through inductance coils producing electrical current.

In the News

  • Waves of Power ( - PhysOrg article introduces the technology, citing work being done at Oregon State University. (May 17, 2005)
  • Making energy waves in Gardiner ( Oregon State University engineering professors currently working on three prototypes of the buoys, which they hope to test at the site and eventually develop into a wave energy "park." (NewsReview; Oregon; April 7, 2005)
  • Waves power future ( - OSU stakes claim to wave energy research center (Gazette Times; Feb. 5, 2005)

Related Sites

See also

- Other directory listings
- PESWiki home page