Pentland Survey Work Now Underway

6th August 2013

Detailed sea-survey work for a tidal stream electricity 'array' in the Pentland Firth is in full swing just now with specialist vessel Lia.

The officers and crew of a specialist vessel, owned by a venerable British family business with a history dating back over 200 years, have been busy this week (starting 04.08.13) in the Pentland Firth conducting detailed surveys in connection with a planned sub-sea 'tidal stream electricity' power station.

The 15.3 metre long aluminium-built catamaran Lia is being utilised by the consortium that was awarded one of four seabed stakes in the Firth during the 'first round' of Crown Estate seabed leases, issued in 2010.

Lia is operating for the lease-holder, a 50:50 joint venture between Perth-based SSE (Scottish & Southern Energy) Renewables Ltd and 'horizontal hydro' turbine developers Open Hydro Tidal Technologies Ltd , of Dublin, Ireland, famous in the nascent industry for its unique 'polo-mint' design. The latter is now controlled by French naval shipbuilder DCNS, following a majority-stake sale finalised in March this year.

Cantick Head Tidal Development Ltd, as the concessionaire is known, aims to have around 30 MW of turbine capacity installed for 2015/2016, with the site's full 200 MW capacity generating by 2020/21.

Although the 11 square kilometre site is known as 'Cantick Head', after the cape with the prominent lighthouse at the eastern tip of South Walls that marks the main sea-route from the Firth into Scapa Flow, the array's planned location is now more likely to be off Hoy's Brims Ness.

This is because earlier surveys, including works done by Mey-based Energy Hunt Ltd, showed that a similar-size sea area overlapping Westwards from the originally-awarded site, offers superior power-generation prospects.

The Lia's intensive 2013 summer works, in waters between 60 and 80 metres deep, are a precursor to an early 'consenting' application to Marine Scotland. The location lies between 7 and 8 miles North-North-West from Gills Bay.

The vessel is operated by Osiris Projects, of Merseyside. This is now part of Bibby Group Marine Survey Services Ltd, which is in turn a component of the Bibby Line Group, of Liverpool. The diversified business that has been in the founding Bibby family hands since 1809, now has ship-owning and management, financial services and retail (the 'Costcutter' chain) in its portfolio, while it opened an Aberdeen-based offshore energy-support unit nine years ago.

Bibby Line became famous in the 19th and early 20th centuries for its role in providing essential passenger and freight-goods shipping sea-links between Britain and its far-flung former Empire, especially with the Indian sub-continent.

The Cantick Head site will become almost certainly the second one to be developed in the Firth, partly overlapping with the deployment of MeyGen Ltd's initial 6-turbine 'demonstration array' in the much shallower Inner Sound planned from mid-2014 onwards.

Scottish Power Renewables Ltd, which has the Crown Estate Ness of Duncansby seabed lease off John O'Groats, is first developing its 10-turbine 'demonstration array' in the more sheltered Sound of Islay seabed site, also starting next year.

The other 'first round' lease in the Firth was awarded to Marine Current Turbines Ltd, off Broughness, the southernmost tip of South Ronaldsay, where a white-painted former Coastguard Station was prominent.

MCT, which has operated the successful tidal turbine in Northern Ireland's Strangford Lough for the past five years, is now part of the German-controlled Siemens group. It is understood that it is looking for a utility partner company for its Broughness's development.

Like the area's best known twin-hulled vessel, the Gills Harbour ferry Pentalina, the Lia was designed in Australia. Although she can cruise at a respectable 16 knots, she has specialist on-board 'trolling valves' which allow the shallow-draught vessel to be kept under full control at speeds as low as 1 knot, if required.

Lia has a through-deck 'moonpool' with an on-board hydraulic crane allowing her to deploy side-scan and ROV (remote operated vehicle) equipment. for detailed seabed studies.

She is under the same ownership/management as Chartwell, which kicked off Wick Harbour's involvement as a shore-base for Moray Firth offshore wind. This was when Chartwell was based at the Caithness port for an extended spell in 2011/2012. This was reportedly thanks to locally-born on-board marine surveyor Mr Chris Sinclair, whose father John is the MD of Caithness Creels Ltd, now the only significant fishing-gear manufacturer in the Caithness town.

John Thouless is SSE's Marine Developments Manager, responsible for Cantick Head and others of its off-shore sites. SSE is Britain's largest renewable-electricity generator, having taken over the 1950s-built North of Scotland Hydro Electric Board power-stations, many of which it is upgrading in an multi-million pound on-going programme.

In view of the proximity of the Cantick Head seabed site, Mr Thouless has asked to be kept fully abreast of developments suitable for tidal stream vessel usage at Gills Harbour and has reserved the right to make suitable suggestions, if necessary.

Open Hydro is continuing to test its latest 'open centre' prototype turbine at the European Marine Energy Centre's (EMEC) tidal site off Eday, Orkney this year.

Reporter Bill Mowat