Tidal turbine connects to grid off Orkney

The AR1000 turbine could power up to 1,000 homes

Scotland's first grid-connected commercial-scale tidal turbine has begun generating power.

The three-bladed device, which could generate enough electricity for about 1,000 homes, has been installed in waters off Orkney.

The AR1000 turbine is claimed to be the world's most powerful single-rotor tidal device.

It was developed by the international marine energy firm Atlantis Resources Corporation.

The device, which stands 22.5m (73ft) tall and weighs 1,500 tonnes, could generate up to one megawatt of power.

Atlantis said it was one of the largest bladed turbines of its kind ever built, with a rotor diameter of 18m (59ft).

The turbine design draws heavily from development and testing of the company's earlier two-rotor AK1000 turbine which was assembled in 2010 in Invergordon before being shipped to Orkney.

The AR1000 was brought in after initial installation of the two-rotor version at the European Marine Energy Centre's test site off the island of Eday was hampered by a fault with the device's blades.

The turbine is due to undergo tests over two years, ahead of a planned large-scale deployment in the Pentland Firth.

Last year the Crown Estate awarded the MeyGen consortium - which includes Atlantis Resources - a 25-year operational lease for a site which lies between the Caithness coast and the island of Stroma.

The consortium has drawn up a scheme which could involve up to 400 submerged turbines, generating enough energy to power 400,000 homes.

Subject to planning permission, construction is expected to take place on a phased basis until 2020.