A tidal turbine said to be the world's most powerful is due to begin testing in Orkney.

The turbine is 63 metres (206ft) long and can generate more than 2MW of power.

Scottish energy minister Paul Wheelhouse said the Scotrenewables SR2000 turbine has the "potential to be a real game changer in the industry".

He visited Hatston pier in Orkney where the unit is undergoing final checks before being connected to its mooring system on the European Marine Energy Centre's (EMEC) high-speed tidal test site west of Eday.

He said: "Scotland's capacity to generate tidal power is considerable and this device has the potential to be a real game changer for the industry, not only here in Scotland but across the world.

"Floating technology like this is likely to be easy and cheap to install, maintain and decommission.

"This will increase the commercial viability of tidal energy, which is crucial as we continue to transition towards a low carbon economy."

Scotrenewables chief executive officer Andrew Scott said: "The Scottish Government has been consistent in their vision and support for the marine renewables sector and that has been vital in getting a second generation technology like ours to this stage, and it is great to have the minister come to see and hear about the exciting opportunities we're aiming to create.

"It's obviously a critical phase in the project but we're looking forward to the test programme and providing clear evidence of the significant advantages our technology can bring to the sector whilst offering a step reduction in costs."

Environmental charity WWF Scotland welcomed the development.

Director Lang Banks said: "News that the world's most powerful tidal turbine is to begin trials in Orkney underlines the important role Scotland currently plays in the development of marine renewables globally.

"We hope the sea trials are successful and the findings are helpful to the wider industry as it seeks to find cost-effective ways to harness the pollution-free power of our seas.

"Alongside measures to improve energy efficiency, marine renewables have the potential to play a significant role in powering our homes and businesses in the future."

The news came a day after a Scottish energy firm announced its tidal array system had become the first in the world to deliver electricity to the national grid from two linked underwater turbines.

Nova Innovation said its Shetland Isles project represents major progress in using tidal energy as a long-term source of predictable renewable power.

The company installed its first turbine in the Bluemull Sound in March, with the device generating to full power across all tidal conditions. A second turbine was installed in August to work alongside the first.