Oyster wave energy converter
Encyclopedia
The Oyster is a hydro-electric wave energy device that uses the motion of ocean waves to generate electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...

. It is made up of a Power Connector Frame (PCF), which is bolted to the seabed, and a Power Capture Unit (PCU). The PCU is a hinged buoyant flap that moves back and forth with movement of the waves. The movement of the flap drives two hydraulic pistons that feed high-pressured water to an onshore hydro-electric turbine, which drives a generator to make electricity. Oyster is stationed at the European Marine Energy Centre
European Marine Energy Centre
The European Marine Energy Centre is a research centre focusing on wave and tidal power development based in the Orkney Islands, UK. It claims to provide developers with the opportunity to test full-scale grid-connected prototype devices in unrivalled wave and tidal conditions...

 (EMEC) at its Billia Croo site in Orkney, Scotland and is currently the world's largest operating wave energy device.

Aquamarine Power installed Oyster at the EMEC in August 2009. On November 20, 2009, Oyster was officially launched and connected to the National Grid (UK) by the First Minister of Scotland
First Minister of Scotland
The First Minister of Scotland is the political leader of Scotland and head of the Scottish Government. The First Minister chairs the Scottish Cabinet and is primarily responsible for the formulation, development and presentation of Scottish Government policy...

, Alex Salmond
Alex Salmond
Alexander Elliot Anderson "Alex" Salmond MSP is a Scottish politician and current First Minister of Scotland. He became Scotland's fourth First Minister in May 2007. He is the Leader of the Scottish National Party , having served as Member of the Scottish Parliament for Gordon...

.

Current developments are underway to build a more efficient and powerful second-generation device, Oyster 2.

History

Oyster was developed by Edinburgh-based Aquamarine Power
Aquamarine Power
Aquamarine Power is a wave energy company, which was founded in 2005 to commercialise a wave energy device concept known as the Oyster wave energy converter. The company's head offices are based in Edinburgh...

, a company that focuses on wave energy. The concept originated from research at Queen’s University, Belfast, led by professor Trevor Whittaker, Head of the Wave Power Research Centre at Queen's. Aquamarine Power also teamed up with Renewable Technology Ventures Ltd (STVL), a subsidiary of Scottish and Southern Energy (SEE), to fund the Oyster project. Aquamarine Power was able to secure a £6.3m investment from Scottish Enterprise. In addition, Scottish Enterprises awarded Aquamarine Power a £3.15 million grant from the Wave and Tidal Energy: Research, Development and Demonstration Support fund (WATERS). Aquamarine Power also received £1.5m from Sigma Capital Group plc. Altogether, Aquamarine Power was able to raise £11 million to stage this project.

In June 2009, Aquamarine Power signed a £2.5 million contract with Frugo Seacore to install the Oyster device at the European Marine Energy Centre
European Marine Energy Centre
The European Marine Energy Centre is a research centre focusing on wave and tidal power development based in the Orkney Islands, UK. It claims to provide developers with the opportunity to test full-scale grid-connected prototype devices in unrivalled wave and tidal conditions...

 test site at Billia Croo. Oyster was installed 400 metres offshore, west of the Orkney mainland, in 12 metre-deep water. Oyster was installed in August 2009; however it was officially launched on November 20, 2009 by the First Minister of Scotland
First Minister of Scotland
The First Minister of Scotland is the political leader of Scotland and head of the Scottish Government. The First Minister chairs the Scottish Cabinet and is primarily responsible for the formulation, development and presentation of Scottish Government policy...

, Alex Salmond
Alex Salmond
Alexander Elliot Anderson "Alex" Salmond MSP is a Scottish politician and current First Minister of Scotland. He became Scotland's fourth First Minister in May 2007. He is the Leader of the Scottish National Party , having served as Member of the Scottish Parliament for Gordon...

. That same day, Oyster was connected the National Grid (UK) and began generating electricity.

Aquamarine Power hopes to commercialize Oyster and has already signed an agreement with Scottish and Southern Energy to develop up to 1000MW of wave farms by 2020.

Operation

Oyster harnesses the energy of near-shore ocean waves; it was designed to operate in water 10 to 12 metres deep. The Oyster is made up of a Power Connector Frame (PCF) and a Power Capture Unit (PCU). The 36-ton PCF is bolted to the seabed
Seabed
The seabed is the bottom of the ocean.- Ocean structure :Most of the oceans have a common structure, created by common physical phenomena, mainly from tectonic movement, and sediment from various sources...

 by 1-by-4 meter concrete piles that are drilled 14 metres deep into the seabed. The PCF requires careful and accurate positioning and leveling to compensate for the uneven, rocky seabed. The PCU is a 200-ton, 18-by-12-by-4 metre buoyant flap that is hinged to the PCF. In order to lower the PCU into the water to hinge it to the PCF, 120 tons of seawater must be pumped into ballast tanks within the PCU to provide sufficient negative buoyancy to aid its descent into the water. The PCU is almost entirely submerged underwater; only 2 metres of the device poke above the water. The PCU sways back and forth with the movement of the waves, and this movement of the flap drives two hydraulic piston
Piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from...

s that pump high-pressured water through three sub-sea pipeline to an onshore hydro-electric water turbine
Water turbine
A water turbine is a rotary engine that takes energy from moving water.Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now they are mostly used for electric power generation. They harness a clean and renewable energy...

. The turbine then drives a 315 kW electrical generator
Electrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...

, which converts the wave energy into electricity.

The European Marine Energy Centre
European Marine Energy Centre
The European Marine Energy Centre is a research centre focusing on wave and tidal power development based in the Orkney Islands, UK. It claims to provide developers with the opportunity to test full-scale grid-connected prototype devices in unrivalled wave and tidal conditions...

 classifies Oyster as an Oscillating Wave Surge Converter:
This device extracts the energy caused by wave surges and the movement of water particles within them. The arm oscillates as a pendulum mounted on a pivoted joint in response to the movement of water in the waves.

Potential

There are several advantages to using a device like the Oyster:
  • Oyster itself has few moving parts underwater. Its simplicity allows for survivability: in extreme weather conditions, Oyster’s hinged flap can simply move and duck under large waves.
  • Because all of Oyster’s electrical components are located onshore, the hydro-electric generator is accessible for maintenance 24/7. The actual Oyster device is near shore, making it easily accessible, as well.
  • Oyster uses renewable energy from ocean waves to generates clean, zero-emission electricity. This minimizes the environmental risks involved compared to electricity that is produced from fossil fuels. The Carbon Trust estimates that each Oyster device can avoid over 500 tons of carbon dioxide from being released into the atmosphere annually.
  • Aquamarine Power estimates that a farm of 20 Oyster units could produces enough energy to power 9,000 homes.
  • According the Aquamarine Power's CEO Martin McAdam:

"A successful Oyster project would unlock £3-4 million of capital expenditure per MW installed, of which a significant proportion would be invested in the Orkney economy. A commercial wave farm could therefore represent a significant boost to the local economy and would provide long-term skilled jobs for local residents. Ongoing operations and maintenance would generate a further £150,000 per annum to the local economy."

It is esimated that advances in the marine energy industry could provide as many as 12,500 jobs, contributing £2.5 billion to the UK economy by 2020.

  • Aquamarine Power hopes to commercialize and expand the Oyster technology. Ronan Doherty, Chief Technical Officer of Aquamarine Power, found that coastlines off Spain, Portugal, Ireland, Britain, United States, South Africa, Australia and Chile have great wave energy potential and would be ideal places to install Oyster. Doherty predicts that the Oyster market has a £50 billion potential.

Challenges

There are also many disadvantages to using a device like the Oyster:
  • The installation and production of Oyster is difficult and expensive.
    • Oyster weighs over 200 tons; it must be carried out to sea in a large flat-top barge and installed in several stages. First, the PCF is lowered and bolted in the seabed, and it must be accurately positioned and leveled to compensate for the uneven seabed. Then, 120 tons of seawater must be pumped into ballast tanks within the PCU to provide sufficient negative buoyancy to aid its descent into the water to be hinged to the PCF. This complex process involves employing many workers and using expensive equipment.
    • To deploy more Oyster units, new cables will be needed to install the devices into the National Grid.
  • Oyster's offshore turbine and generator can produce noise pollution
    Noise pollution
    Noise pollution is excessive, displeasing human, animal or machine-created environmental noise that disrupts the activity or balance of human or animal life...

    , thereby disturbing onshore wildlife. However, most of this noise is expected to be masked by the surrounding noise generated by the wind and waves.
  • The installation and operation of the Oyster could interfere with marine mammal life and fish life. The movement of the Oyster device produces underwater noise and vibrations. The noise can mask natural sounds (thus disturbing communication between marine wildlife), produce stress, and cause hearing loss in marine species.
  • Deploying several Oyster units could result in loss of habitat for marine species.

Oyster 2

Current developments are underway to construct an improved, second-generation Oyster device, Oyster 2. In December 2010, Aquamarine Power signed a £4 million contract with Scotland’s leading fabrication contractor Burntisland Fabrications Ltd (BiFab). BiFab began manufacturing Oyster 2 at its manufacturing plant in Methil, Fife, Scotland, and the device is expected to be in full operation by the summer of 2011 at the European Marine Energy Centre
European Marine Energy Centre
The European Marine Energy Centre is a research centre focusing on wave and tidal power development based in the Orkney Islands, UK. It claims to provide developers with the opportunity to test full-scale grid-connected prototype devices in unrivalled wave and tidal conditions...

.

Aquamarine Power has secured funding from many sources for the development of Oyster 2:
  • In February 2010, Aquamarine Power received a grant of £5.1 million from the Marine Renewables Proving Fund (MRPF), which is funded by the United Kingdom’s Department of Energy and Climate Change
    Department of Energy and Climate Change
    The Department of Energy and Climate Change is a British government department created on 3 October 2008 by Prime Minister Gordon Brown to take over some of the functions of the Department for Business, Enterprise and Regulatory Reform and Department for Environment, Food and Rural Affairs...

     and managed by the Carbon Trust.
  • Renewable Technology Ventures Ltd (STVL), a subsidiary of Scottish and Southern Energy (SEE), has invested an additional £2.7 million, bringing its total investment in Aquamarine Power to £19.8 million over the last three years.
  • ABB, the automation and power technology company, has invested £8 million in Aquamarine Power.


Oyster 2 will employ the same basic technology of the original Oyster; however, it will feature a different shape that will maximize the amount of energy that the device is able to capture from the waves. Oyster 2 will consist of three 800 kW flaps that will all be linked to one pipeline leading to an onshore 2.4 MW hydro-electric generator. Each flap will measure 26 metres, making it 50% larger than the original Oyster. Oyster 2 will also have a 250% greater power output. Aquamarine Power estimates that a small farm of 20 Oyster 2 devices will be capable of supplying enough electricity for over 12,000 homes, compared to the 9,000 homes the original Oyster is capable of powering.

See also

  • Wave power
    Wave power
    Wave power is the transport of energy by ocean surface waves, and the capture of that energy to do useful work — for example, electricity generation, water desalination, or the pumping of water...

  • Hydropower
    Hydropower
    Hydropower, hydraulic power, hydrokinetic power or water power is power that is derived from the force or energy of falling water, which may be harnessed for useful purposes. Since ancient times, hydropower has been used for irrigation and the operation of various mechanical devices, such as...

  • Marine energy
    Marine energy
    Marine energy or marine power refers to the energy carried by ocean waves, tides, salinity, and ocean temperature differences. The movement of water in the world’s oceans creates a vast store of kinetic energy, or energy in motion...

  • Aquamarine Power
    Aquamarine Power
    Aquamarine Power is a wave energy company, which was founded in 2005 to commercialise a wave energy device concept known as the Oyster wave energy converter. The company's head offices are based in Edinburgh...

  • European Marine Energy Centre
    European Marine Energy Centre
    The European Marine Energy Centre is a research centre focusing on wave and tidal power development based in the Orkney Islands, UK. It claims to provide developers with the opportunity to test full-scale grid-connected prototype devices in unrivalled wave and tidal conditions...

  • Queen's University Belfast

External links

  • Aquamarine Power http://www.aquamarinepower.com/
  • Aquamarine Power on YouTube http://www.youtube.com/aquamarinepowerltd
  • European Marine Energy Centre http://www.emec.org.uk
  • Scottish and Southern Energy http://www.scottish-southern.co.uk/SSEInternet/
  • Queen's University Belfast http://www.qub.ac.uk/
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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