The wave-powered generator is a hinged flap connected to the sea-bed
A major wave energy device sited off Orkney has been switched on by First Minister Alex Salmond.
The move saw Aquamarine Power's 'Oyster' being connected to the national grid as part of sea trials.
The wave-powered generator is a hinged flap connected to the sea-bed, with each wave moving the flap to drive a hydraulic piston.
Mr Salmond said: "This is a key milestone for Scotland's marine renewables sector."
More work and investment is required in the coming years to make it commercially viable.
A farm of 20 Oysters could provide energy to power 9,000 three-bedroom homes.
The Stromness-based European Marine Energy Centre's managing director, Neil Kermode, said: "EMEC are delighted to see Oyster installed, running and on test."
Mr Salmond also announced new funding of £975,000 to help deliver 'Oyster 2'.