A wave energy system which operates at least six metres (19ft) below the sea's surface will be tested off Orkney.
An artist's impression of the Archimedes Wave Swing
AWS Ocean Energy will have a demonstration version of its Archimedes Wave Swing installed by the European Marine Energy Centre (Emec).
The Ross-shire manufacturer's device is a cylinder-shaped buoy which is moored to the seabed.
Passing waves move an upper casing against a lower fixed cylinder and the movement is converted into electricity.
The Archimedes Wave Swing will be installed off Orkney next year with the support of a £2.1m Scottish Executive grant.
AWS said that because the system was submerged below the surface, it was "invisible" and would not cause a visual impact or become a hazard to shipping.
It can also survive violent storms, according to the Alness-based company.
Stromness-based Emec was set up to help companies develop marine energy schemes from the prototype stage.