The Pentland Firth could potentially generate power equivalent to almost half of Scotland’s annual electricity consumption.
New research led by the University of Oxford suggests that the maximum that the firth, which separates the Orkney Islands from mainland Scotland, could produce would be 1.9GW, with 1GW a more realistic target.
This is well below previous estimates of 10GW to as much as 20GW, which saw Scotland First Minster Alex Salmond refer to the firth as the "Saudi Arabia of tidal power", but could still account for half of Scotland's annual electricity consumption, which amounted to 37TWh in 2011.
"Our study provides the first robust data about how much energy it would be feasible to extract," said Thomas Adcock, lead author of the report and fellow in engineering science at Oxford University.
The study took into account factors such as how many turbines it would be feasible to build, how they would interact with each other and variations from tidal cycles and found that a maximum of three rows of turbines could be deployed in the Pentland Firth without disturbing the generation capacity of the tidal flow.
Despite their estimate being much lower than previously expected the researchers claim the firth, which has currents running at up to 5m/s, is still potentially the world’s most important location for tidal turbine technology and so far the Crown Estate has entered into leasing agreements for projects in the area with a potential capacity of up to 1.6GW.
David Krohn, RenewableUK’S Wind and Tidal Energy development manager said: “Scotland’s potential for developing tidal power is amongst the highest in the world. While the Pentland Firth is undoubtedly the jewel in the crown, Scotland’s large coastline and archipelagos contain a number of significant sites.
“Kyle Rhea and Islay are currently under development and have received upfront capital support from the UK Government and the European commission respectively. The Crown Estate has granted leases for a further 14 sites across Scotland, including the extremely promising Cantick Head, Brough Ness and Lashy Sound sites.
“In addition, technological advancements made by the industry, such as floating platforms, allow us to extract more energy from tidal flows.
“The development of the world leading tidal energy industry in Scotland has been partly down to the consistent support it has received from the Scottish Government.
“This support has been based on the fact that a sizeable proportion of Scotland’s energy requirements can be sourced from the tides but also on the recognition that Scotland, and the UK more widely, can capitalise on the significant global opportunity by supplying skills, goods and services to tidal energy projects in other parts of the world”.
Marine energy is still in its infancy worldwide compared with other renewable sources such as wind or solar power and no large-scale commercial wave or tidal facility is yet in operation.
Britain is betting on its potential, aiming for 100 to 200MW of wave and tidal energy installed by 2020 but has yet to make the leap from prototype to full-scale arrays.
The study was published in the journal Proceedings of the Royal Society A.
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