The Pelamis Wave Energy Converter was a technology that used the motion of

ocean surface wave In fluid dynamics, a wind wave, water wave, or wind-generated water wave, is a surface wave that occurs on the free surface of bodies of water as a result from the wind blowing over the water surface. The contact distance in the direction o ...

s to create electricity. The machine was made up of connected sections which flex and bend as waves pass; it is this motion which is used to generate electricity. Developed by the now defunct Scottish company Pelamis Wave Power (formerly Ocean Power Delivery), the Pelamis became the first offshore wave machine to generate electricity into the grid, when it was first connected to the UK grid in 2004. Pelamis Wave Power then went on to build and test five additional Pelamis machines: three first-generation P1 machines, which were tested in a farm off the coast of Portugal in 2009, and two second-generation machines, the Pelamis P2, were tested off Orkney between 2010 and 2014. The company went into administration in November 2014, with the

intellectual property Intellectual property (IP) is a category of property that includes intangible creations of the human intellect. There are many types of intellectual property, and some countries recognize more than others. The best-known types are patents, cop ...

transferred to the Scottish Government body Wave Energy Scotland.

Operation

The Pelamis machine is an offshore wave energy converter, operating in water depths greater than 50m. The machine consists of a series of semi-submerged cylindrical sections linked by hinged joints. As waves pass along the length of the machine, the sections move relative to one another. The wave-induced

motion In physics, motion is the phenomenon in which an object changes its position with respect to time. Motion is mathematically described in terms of displacement, distance, velocity, acceleration, speed and frame of reference to an observer and m ...

of the sections is resisted by

hydraulic cylinder A hydraulic cylinder (also called a linear hydraulic motor) is a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke. It has many applications, notably in construction equipment ( engineering vehicles ...

s which pump high pressure oil through hydraulic motors via smoothing

hydraulic accumulators A hydraulic accumulator is a pressure storage reservoir in which an incompressible hydraulic fluid is held under pressure that is applied by an external source of mechanical energy. The external source can be an engine, a spring, a raised weight, ...

. The hydraulic motors drive

electrical generator In electricity generation, a generator is a device that converts motive power (mechanical energy) or fuel-based power ( chemical energy) into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, g ...

s to produce electricity. Electricity from all the joints is fed down a single

umbilical cable An umbilical cable or umbilical is a cable and/or hose that supplies required consumables to an apparatus, like a rocket, or to a person, such as a diver or astronaut. It is named by analogy with an umbilical cord. An umbilical can, for example, ...

to a junction on the

sea bed The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as 'seabeds'. The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...

. Several devices can be connected and linked to shore through a single seabed cable.

Principle

The Pelamis is an attenuating wave energy converter. The machine responds to the curvature of the waves (their shape) rather than the wave height. As waves can only reach a certain curvature before naturally breaking, this limits the range of motion through which the machine must move but maintains large motion at the joints in small waves.

Projects

P2 Pelamis testing at EMEC

The P2 Pelamis design was Pelamis Wave Power's second generation Pelamis machine. The Pelamis P2 is 180m long, 4m diameter and approximately 1350 tonnes in weight. Consisting of five tube sections and four flexible joints, the design is longer and fatter than the previous P1 design. In 2010, Pelamis Wave Power began tests of the first Pelamis P2 machine at the European Marine Energy Centre, Orkney, Scotland. The machine was owned by the German utility company, E.ON, and was the UK's first commercial supply contract in the

marine energy Marine energy or marine power (also sometimes referred to as ocean energy, ocean power, or marine and hydrokinetic energy) refers to the energy carried by ocean waves, tides, salinity, and ocean temperature differences. The movement of water in ...

sector. In March 2010 Pelamis Wave Power announced a second order for a P2 machine, from ScottishPower Renewables, part of

Iberdrola Renovables Iberdrola Renovables was a subsidiary of Iberdrola, headquartered in Valencia, Spain, which included companies in the domains of renewable energy, particularly wind power. The firm was the world's largest renewable energy firm: it was the worl ...

. This second machine was first installed at EMEC in May 2012. The two utility companies announced that they will work together to share and collaborate in testing of the P2 Pelamis technology. Following the demise of the company, the P2-001 device was acquired by Wave Energy Scotland, having completed over 15,000 hours of operation. The device was decommissioned in April 2016 and sold to the Orkney Island Council for £1. The other device, P2-002 was sold to the European Marine Energy Centre for use as a test rig.

Projects formerly in development

E.ON and ScottishPower Renewables announced plans to build larger projects using Pelamis machines in the waters off Orkney's west coast. Both companies won leases in 2010 from

The Crown Estate The Crown Estate is a collection of lands and holdings in the United Kingdom belonging to the British monarch as a corporation sole, making it "the sovereign's public estate", which is neither government property nor part of the monarch's priva ...

, who own the seabed around the UK, for projects of up to 50 MW. The "Pentland Firth and Orkney Waters Leasing Round" was the world's first commercial scale wave and tidal energy leasing opportunity.

Development history

Prototype Pelamis Machine

Pelamis Wave Power tested their first full-scale prototype at the European Marine Energy Centre in Orkney, Scotland between 2004 and 2007. The machine, which was rated at 750 kW, was the world's first offshore

wave power Wave power is the capture of energy of wind waves to do useful work – for example, electricity generation, water desalination, or pumping water. A machine that exploits wave power is a wave energy converter (WEC). Waves are generated by win ...

machine to generate electricity into the grid system. The prototype was 120m long and 3.5m in diameter. It consisted of four tube sections linked by three, shorter, and power conversion modules

Aguçadoura Wave Farm

In 2008 Pelamis tested three first generation, P1 Pelamis waves at the Aguçadoura Wave Farm. Located off the northwest coast of

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...

near

Póvoa de Varzim Póvoa de Varzim (, ) is a Portugal, Portuguese city in Norte Region, Portugal, Northern Portugal and sub-region of Greater Porto, from its city centre. It sits in a sandy coastal plain, a cuspate foreland, halfway between the Minho River, Minho ...

, the farm had an installed capacity of 2.25 MW and was the world's first multiple machine wave power project. The project was part funded by Portuguese utility Enersis, at the time owned by Australian global investment company Babcock & Brown. The farm first generated electricity in July 2008 but was taken offline in November 2008 at the same time as Babcock & Brown encountered financial difficulties.

Etymology

'' Pelamis platurus'' is a yellow-bellied

sea snake Sea snakes, or coral reef snakes, are elapid snakes that inhabit marine environments for most or all of their lives. They belong to two subfamilies, Hydrophiinae and Laticaudinae. Hydrophiinae also includes Australasian terrestrial snakes, wher ...

that lives in tropical and subtropical waters. It prefers shallow inshore waters.

Hailong 1

The Hailong (Dragon) 1 is a Chinese wave energy machine reported to be a near perfect copy of the Pelamis which began testing in 2015 in the

South China Sea The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by the shores of South China (hence the name), in the west by the Indochinese Peninsula, in the east by the islands of Taiwan and northwestern Phi ...

. It was reported to have been based on IP stolen from Pelamis during a 2011 heist.

Images

Image:Pelamis Wellenkraftwerk Portugal 1.JPG, 2 of 3 Pelamis machines in the harbour of Peniche,

. Image:Pelamis at EMEC.jpg, Pelamis prototype machine at EMEC. Image:Pelamis bursts out of a wave.JPG, The front of the Pelamis machine bursting through a wave at the Aguçadoura Wave Park Image:Pelamis machine installed at the Agucadoura Wave Park.JPG, 1 of 3 Pelamis machines at the Aguçadoura Wave Farm

References

External links

Aegir Wave PowerThe European Marine Energy Test CentreThe Power Technology websitePelamis Secures Wave Energy Order from E.onPelamis at Aguçadoura video
{{Sustainable development in Scotland 2007 introductions Buildings and structures in Orkney Wave energy converters Wave farms in Portugal Wave farms in Scotland