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Pentland Firth tides have potential to power almost half of Scotland

10 July 2013

Title: The available power from tidal stream turbines in the Pentland Firth

Authors: Thomas A. A. Adcock, Scott Draper, Guy T. Houlsby, Alistair G. L. Borthwick and Sena Serhadlıoğlu

Journal: Proceedings of the Royal Society A

The first robust estimates of the maximum potential power output from Scotland’s Pentland Firth are revealed in Proceedings of the Royal Society A today.

Researchers from the University of Oxford found that a maximum of 1.9GW could be generated from tidal turbines placed in the stretch of water, with 1GW being a more realistic estimate. However, a Scottish Government website previously claimed that the potential output was 14GW.

Although the researchers estimate that the power output could be much lower than previously expected, lead author Dr Thomas Adcock and his colleagues claim that the Pentland Firth is potentially the world’s most important location for tidal turbine technology. They add that their new estimate means that the Firth could potentially generate power equivalent to almost half of Scotland’s annual electricity consumption.

The Pentland Firth is the strait connecting the Atlantic Ocean to the North Sea between mainland Scotland and the Orkney Isles. The strait is well known to have exceptionally fast tidal currents, and has become a focal point for tidal stream power device developers. The tidal currents, which can exceed 5 metres per second, are principally due to the difference in water level across the Pentland Firth, established as the tide propagates from the Atlantic Ocean and around the Orkney Isles into the North Sea.

The study investigates the maximum number of turbines that could be placed in the Pentland Firth without interrupting the flow of the current and hence adversely affecting the amount of electricity generated. They found that three rows of turbines would be the maximum number that should be placed in the firth and hence calculated the electricity that could be generated from this arrangement.