The wave farm, which in its first phase will generate clean electricity for up to 1,500 homes at peak output, consists of three semi-submerged, 142m long, 700 ton carbon steel cylindrical wave energy converters designed and built by Pelamis Wave Power. The Agucadoura station will eventually add another 25 Pelamis units, generating 21MW of power whilst saving 60,000 tons of CO2 per year compared to a conventional fossil fuel plant.

Each wave converter is comprised of four articulated sections which move up and down as the wave passes. At the hinges between sections, hydraulic rams use the wave motion to drive generators, producing power which is carried by undersea cable to the Agucadoura substation and fed into the Portuguese national grid.

Pelamis Wave Power needed vessels for both sea trials of the machines and their eventual installation in Portugal. Being based in Edinburgh, they looked toward Shetland Island company Delta Marine to supply workboats. However, providing a support vessel for something that has never been constructed before is not the easiest of remits.

The first workboat on the job, the multicat type Voe Venture,  proved itself capable as a trials vessel, pulling the Pelamis machines behind to see how they reacted in sea conditions.

Delta Marine's David McNaughtan was visiting at that time and tells MJ that it wasn't long before he realised that the Voe Viking, at that moment just coming off the drawing board, would be perfect for the next stage of the operation. The Voe Viking is a 26m Damen Multi Cat 2611 with two Effer 180.000 3S deck cranes that can lift 10 tons at 16 metres, and a towing winch with 30 tons of pull, amongst other equipment.

'Availability of deck space, size of cranes, layout of the vessel and towing capability were all just what they needed, said McNaughtan. 'The Pelamis team said that they couldn't have done better if they had sat down and designed it themselves.' He added that the boat has definitely 'been used to capacity.'

It has been an exciting project, with a few unexpected twists, rather like sea snakes themselves. For example, the technology keeping the snakes in place and linked to the grid has caused something of a headache.

Mr McNaughtan explained that four anchors and an electrical cable come into one point, with a 'plug'  designed to float between 15 and 20m below the surface. But the sea conditions at Orkney, where the plugs were developed proved slightly different to those in Portugal, and they just wouldn't maintain their position. Finally, the Pelamis team got the buoyancy right.

With the installation now up and running, both Delta Marine and Pelamis Wave Power are looking to the future completion of the entire 28 unit wave farm. It is, however, a sad commentary on UK Government support for indigenous renewable energy technologies that Pelamis had to go to Portugal to find a market.