Plans to establish a major new windfarm in the waters of the Inner Hebrides have been dropped by energy company ScottishPower Renewables.

The company said the Argyll Array project was currently not financially viable in the short term.

It said hard rock at the site, off the coast of the island of Tiree, made it difficult to develop, while "challenging" wave conditions also impacted on the project.

Another issue was the significant presence of basking sharks in the area.

The site has the potential to provide a capacity of between 500 megawatts and 1,800 megawatts of electricity, if developed.

Jonathan Cole, the head of offshore wind at ScottishPower Renewables, said the area had "some of the best wind conditions" to be found offshore anywhere in the UK.

But he added the technology was not yet sufficiently developed to allow the project to proceed.

Mr Cole said: "We believe it is possible to develop the Argyll Array site, it has some of the best wind conditions of any offshore zone in the UK.

"However, it is our view that the Argyll Array project is not financially viable in the short term. As cost reductions continue to filter through the offshore wind industry, and as construction techniques and turbine technology continues to improve, we believe that the Argyll Array could become a viable project in the long term.

"The rate of progress in development of foundation and installation technology has been slower than anticipated. The current outlook for offshore wind deployment in the UK suggests this will not significantly improve in the short term. This supports the view that it could take 10-15 years for the required technology improvements to be available for this project."

He said development work "will cease on the project with immediate effect", adding this would give ScottishPower Renewables the opportunity to focus on other projects.

Mr Cole pledged the company would fully construct the West of Duddon Sands project off the coast of Barrow-in-Furness in Cumbria with Dong Energy, and would continue development work on the East Anglia zone with Vattenfall.

Nature campaigners at RSPB Scotland welcomed ScottishPower Renewables' decision that it would not be taking forward its lease to develop the Argyll Array windfarm in the near future.

RSPB Scotland head of planning and development Aedan Smith said: "Whilst Scotland has an impressive offshore wind potential the challenges in finding suitable sites with the least impacts on birds and other marine species and habitats are considerable. Offshore wind needs to be developed very carefully if we are to avoid significant harm to our fantastic natural environment.

"The Argyll Array was always going to be a very difficult offshore windfarm to develop. The site, immediately next to the island of Tiree, is internationally important for a range of marine wildlife. In particular, very large numbers of great northern diver and basking shark use the site and could have been affected by the development. Rare species such as corncrake, and Greenland white-fronted goose also make their home on the island each year and fly across the site on their annual migration."

A Scottish Government spokeswoman said: "Although this announcement by ScottishPower Renewables is disappointing, it does not detract from our ambition to fully capitalise on Scotland's offshore wind energy potential, which we will continue to develop in a sustainable manner."