When completed, MeyGen will be the world’s largest tidal energy project. Construction has now begun in Scotland after majority owners, Atlantis Resources, met the conditions required to draw down government grant finance. Civil engineering work, electronic kit installation and cable laying are part of the onshore infrastructure for transmitting electricity for export. Power conversion, grid connection systems and access roads will be built. Defence contractor Lockheed Martin will make the MeyGen Pentland Firth turbines.
The current-driven power plant in the Pentland Firth will comprise 269 freestanding turbines installed on the ocean floor in an area of 1.4 square miles off the Caithness coast.
Each turbine will be weighed down by three concrete legs. The rotary blades will extend into the tidal flow like windmill sails,.so the whole installation will look like a subsea windfarm, with little chance of the Trump oik or his oleaginous ilk protesting.
MeyGen will commence with a demonstration project of four turbines, construction proceeding on a phased basis. Once onstream, the plant will boast a total capacity of 400MW and could power 175,000 homes. Atlantis expects the first supply of tpower from the seabed to the National Grid in 2016, with 60 of the aquatic turbines installed by 2020.
In November 2014, the ‘groundbreaking’ £70million project was awarded the first-ever Navigator Award at the International Conference on Ocean Energy, in recognition of its “significant contribution to the global marine renewable industry.” Atlantis Resources is rooted in Australia with its HQ in Singapore. In a recent announcement to investors, the London Stock Exchange-listed company announced: “The major construction and supply contractors have commenced design, engineering and procurement works in readiness for commencement of onshore construction at the site. The equity investments in the project by Scottish Enterprise through the Renewable Energy Investment Fund and Atlantis value MeyGen on a post-money equity basis at over £70million.”
So much for awards and equity investment – back to the technology. Plant builder MeyGen offer a science lesson to shine some light on the project: “Sea water is 832 times denser than air, so a 5 knot ocean current has more kinetic energy than a 220mph wind. Therefore ocean currents have a very high energy density and a smaller device is required to harness tidal current energy than to harness wind energy. Tidal current energy takes the kinetic energy available in currents and converts it into electricity. As oceans cover over 70% of Earth’s surface, ocean energy (including wave power, tidal current power and ocean thermal energy conversion) represents a vast source of energy, estimated at between 2,000 and 4,000 TWh per year, enough energy to continuously light between 2 and 4 billion 11W low-energy light bulbs.”
The slow moving blades of a water-powered ocean floor turbine reduce the prospect of damage to sea-life or the ecosystem. Fishermen do not drop nets in the area because they would be quickly lost in the maelstrom. The effect of the project on the pods of orca or killer whales that regularly travel the Firth (feeding on seals) will be closely monitored. Tidal flows should be relatively unaffected.
One limitation to tidal energy provision means that energy can be produced only when the tides are flowing in and out, on average for 10 hours every day. Furthermore debris, extreme weather conditions and the breakneck currents in the Inner Sound of the Pentland Firth between Orkney and the Scottish mainland make building, deploying, connecting and managing such machinery on the seabed there a treacherous and complex challenge. Dynamically positioned ships with massive cranes will be used to deploy the turbines. Weighing 400 tonnes, the turbine support structures will be placed on the seabed during slack water.
A lack of commercial viability and any long-term enthusiasm from the utilities could be a problem, despite Atlantis signing a £50 million deal with Smartest Energy to supply electricity. A lack of local or national control and ownership, and over-optimistic narratives are further concerns. Overshadowed by the Scottish Government’s worthy commitment to renewables, gloom in the tidal camp wasn’t helped by the 2014 demise of the Pelamis project. Then Siemens shut down Marine Current Turbines (MCT). In April 2015 it was announced that MCT have been bought by Atlantis Resources. The tidal devices will be assembled and tested in a dedicated turbine facility at Global Energy’s Nigg Energy Park in Easter Ross, with both Atlantis and MCT integrated at the site.
Harnessing the power of tides and turning it into electricity will hopefully be socially beneficial, and MeyGen will act as a catalyst for marine projects worldwide, showing that the industry can progress from the demonstration stage to commercial arrays. The power of the Pentland Firth has been described as the greatest untapped source of energy in Scotland.
Update 9th November 2015
The MeyGen development’s support infrastructure has made progress with subsea supply chain connections and the installation of 11 Km of cabling. Under Phase 1A of the project four turbines will be installed. The first power is scheduled for delivery in 2016.