Monday 1 December 08 - 17:51
 

Marine Renewables

Renewables Study for Western Isles

A new study, commissioned by Comhairle nan Eilean Siar (Western IslesCouncil), investigates the feasibility of creating a fixed transport link across the five mile wide Sound of Harris and the potential for generating renewable energy from the resources of the Sound to help offset capital expenditure.

Tidal energy devices integrated within a fixed transport link across the five mile wide Sound of Harris would help offset capital expenditure.
Tidal energy devices integrated within a fixed transport link across the five mile wide Sound of Harris would help offset capital expenditure.

The preliminary economic review by a subsidiary of Jacobs Engineering Group Inc., providers of professional technical services, and Metoc, marine environmental design and risk management specialists, recommends a combined causeway and bridge arrangement to replace the existing ferry link. The project costs could ultimately be offset by revenue from energy generation by offshore wind turbines and tidal energy devices, integrated within the proposed structures.

The new fixed link across the Sound, between the isles of Harris and

Berneray, would carry a roadway that would extend the transport network through the whole 130 miles of the Western Isles 'spinal route', from Eriskay to the Butt of Lewis, offering considerable business, leisure and social benefits to the islands and making a fundamental contribution to integration of the scattered communities of the Outer Hebrides.

The project team conducted a review of the renewable resource and

navigation issues, as well as socio-economic factors and civil and structural engineering constraints to develop a series of conceptual development options for evaluation. These ranged from continuing with the current ferry link, through to the ambitious fixed link proposal.

The report identifies the shallowness of the Sound of Harris as an obstacle to the use exclusively of tidal and wave technologies for effective power generation. A two mile long causeway from Berneray to the tiny island of Killegray is proposed, with a row of offshore wind turbines that would be erected adjacent to the structure. A further causeway, or alternatively a hybrid bridge incorporating tidal generators would stretch across the relatively narrow Skaari channel from Killegray to Ensay with a bridge crossing from Ensay to the Harris mainland near Leverburgh, with navigation through the Sound maintained beneath this bridge.

MJ Information No: 22519

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Tidal energy devices integrated within a fixed transport link across the five mile wide Sound of Harris would help offset capital expenditure.

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