THE development of wind farms on Scotland's islands is expected to be given a boost over the next decade as more ferries are built that run on electricity and diesel power.

Caledonian Maritime Assets (CMAL), which owns the Caledonian MacBrayne fleet of vessels, said new demand for overnight electricity generation will be created by berthing the world's first hybrid and hydrogen cell ferries on the islands.

The first of two Clyde-built hybrid ferries, which are powered by a combination of two lithium-ion battery banks and diesel generators, is due to enter service this spring following a £20 million investment by the Scottish Government.

CMAL is also carrying out a feasibility study into using hydrogen fuel cells created as a by-product of renewable energy generation to power zero emission ferries.

Guy Platten, CMAL's chief executive, said he was hoping to secure Government funding for a further nine hybrid or hydrogen cell ferries over the next decade.

This would ensure 11 of the 18 routes off the west coast of Scotland operated by smaller vessels in the CalMac fleet would use the green technology.

As well as reducing the emissions from the ferries themselves, Mr Platten said they could be a game changer in making wind-farm developments more economically attractive on Scotland's islands.

He said: "It will create a market for green electricity which at the moment has no overnight demand.

"I hope the hybrid vessels will act as that catalyst and stimulate that demand.

"The sustainable ferry for the future will move us away from a reliance on fossil fuel. It has so much potential for helping to meet the Government's climate change targets and can form part of the infrastructure for creating sustainable islands."

There are nine community-owned wind farms on islands that have been developed through the Highlands and Islands Enterprise (HIE) Community Renewable Engergy Support Programme. Six are in Orkney, there is one in Tiree, one in Gigha and one in Horshader on the Isle of Lewis.

HIE expects the capacity of community-owned wind farms within its area to double this year, with further developments nearing financial completion in Barra and Vatersay, Lewis and Gigha.

An HIE spokeswoman welcomed the development of hybrid and hydrogen fuel cell-powered ferries.

However, she said more work was needed to demonstrate the potential for powering them from renewable sources.

She said: "We understand it is possible that production of any hydrogen fuel required in the future could be undertaken using locally produced electricity, but the economics of doing so are yet to be proven.

"A significant amount of work is required to understand how the hydrogen might be produced, and if its production could be of direct economic benefit to communities. This is something we would hope to realise if use of hydrogen fuel is to become a reality in the Highlands and Islands."

The two hydrogen ferries from Clyde-based Ferguson shipyard will each emit 48 tonnes less carbon dioxide a year than a usual ferry if powered by renewable sources. The actual CO2 saving will be less as this does not take into account the carbon impact of generating electricity through the national grid.