Tidal Energy Could Power Half of Scotland, Study Finds

Half of Scotland could be powered by renewable tidal energy harvested from a stretch of water off the north coast of the country, according to a new study.

Known as the Pentland Firth, the site is located between mainland Scotland and Orkney, a group of islands just north of it, and is home to some of the fastest tidal currents currents in the British Isles. All told, engineers at the Universities of Oxford and Edinburgh estimate 1.9 gigawatts (GW) could be made available if turbines were installed between the two land masses.

According to the scientists, previous estimates, which ranged from 1-18 GW, were too simplistic or used inappropriate models. The new assessment calculates that while as much as 4.2 GW could be captured, less than 2 GW of energy is a more realistic number since tidal turbines are not perfectly efficient.

"Our research builds on earlier studies by analysing the interactions between turbines and the tides more closely," said Alistair Borthwick, of the School of Engineering at the University of Edinburgh. "This is a more accurate approach than was used in the early days of tidal stream power assessment, and should be useful in calculating how much power might realistically be recoverable from the Pentland Firth."

Turbines must be located across the full width of the channel if the Firth's full potential is to be tapped, the researchers explain. However, in order to mitigate the impact on not only shipping trade but sea life, the team identified a number of sites that could be developed and leased to tidal energy firms.

"The UK enjoys potentially some of the best tidal resources worldwide, and if we exploit them wisely they could make an important contribution to our energy supply," said Guy Houlsby of the Department of Engineering Science at the University of Oxford. "These studies should move us closer towards the successful exploitation of the tides."