Wave Energy – Pelamis

A Wave Energy Converter is a technology that uses the motion of ocean surface waves to create electricity. The Palamis, one of these types of converters, was developed by the Scottish company Pelamis Wave Power - PWP (www.pelamiswave.com), it was the first world’s commercial scale machine to generate electricity into the grid from offshore wave energy.
The first full scale prototype was successfully installed and tested in 2004 at the European Marine Energy Centre in Orkney (Scotland).
The Pelamis consists of a series of semi-submerged cylindrical sections linked by hinged joints. The wave induced relative motion of these sections is resisted by hydraulic rams which pump high pressure oil through hydraulic motors via smoothing hydraulic accumulators. The hydraulic motors drive electrical generators to produce electricity. Power from the system is fed down trough a submarine electrical cable to a junction on the sea bed and then to the shore network. Several devices can be connected together and linked to shore through a single seabed cable[1].
The world's first commercial wave farm is under development in Portugal waters, at the Aguçadora Wave Park near Povoa de Varzim. The wave farm will consist in three Pelamis P-750 machines resulting in a total rated capacity of 2.25 megawatts.

Aguçadoura wave farm:
Owners/Developers: Enersis / Babcock & Brown
Location: 5km off the Atlantic coastline of northern Portugal (substation at Aguçadoura)
Wave generator type: Pelamis P-750 (rated power 750 kW)
Total capacity: 2.25 MW (3x750 kW)

The Aguçadoura wave farm constitute both the world’s first, multi-unit, wave farm and also the first commercial order for wave energy converters. Additionally Enersis have issued a letter of intent to “PWP” for a further 20 MW of Pelamis equipment to expand the initial Aguçadoura project to a larger scheme. Development work for the second phase project is already under way. The Aguçadoura wave energy project in Portugal is supported by a specific feed-in tariff currently equivalent to approximately 0.23 €/kWh [2].

One of the three 750kW Pelamis machines due to be installed under the first phase of the Aguçadoura wave farm off Portugal has produced “several MWhs” of electricity during a short-term test run. All three machines should be deployed by the end of this summer before rougher seas arrive at the end of the season [3].

Future projects:
On February 2007 funding for Scotland's first wave farm was announced by the Scottish Executive. It will be the world's largest, with a capacity of 3 MW generated by four Pelamis machines and a cost of over £4 million. The funding is part of a new £13 million funding package for marine power in Scotland.
Pelamis Wave Power has also expressed an interest in installing Pelamis devices at the Wave hub development off the north coast of Cornwall, in England [1].

References:
[1]: Wikipedia website – accessed on 21/08/08
[2]: Pelamis Wave Power website – accessed on 21/08/08
[3]: Renewable Energy News – Issue 149 – dated 7 August 2008


Posted by Filippo