Aquamarine Power, the company testing a wave power device in the Pentland Firth, last week successfully replaced the cylinder module on its Oyster 800 wave machine as part of a comprehensive summer refit.
The machine, deployed at the European Marine Energy Centre at Stromness, has so far achieved more than 20,000 testing hours in operation in all weather conditions.
The Edinburgh-based business is planning to improve the reliability of the Oyster with the aim of producing more sustained power generation next year, following the installation of enhanced cylinders and upgrades to controls.
If further testing is successful, it will bring forward the company's plans to build a 50-device, 40 megawatt wave farm off Lewis. But that aim is reliant on European Union funding and grid connectivity being in place.
"This is an important waymark on our route to reliable electricity generation," said chief executive Martin McAdam. "This new module incorporates a number of significant upgrades to the one it replaces … We have worked closely with suppliers Hunger Hydraulik and Calder Engineering to make it robust enough to withstand the extreme forces it will experience during operation.
"The Oyster concept clearly works: it is the only wave machine to have operated continuously for three winters, and has generated multiple megawatt hours of electrical power.
"The goal now is to generate electricity reliably. This is a challenge for the whole industry, and it is only through full-scale testing that we can find out what works, what doesn't and the evolutionary changes we need to make."