A COMPANY has unveiled plans for floating gas-fired power stations docked in Scottish ports.

Tower Bridge Ventures has announced proposals for special barges with generating capacity of a total of 375 megawatts, enough to power more than 120,000 homes.

The firm has not said how many of the 196ft-long barges or "power ships" it has in mind.

But its proposals - gradually coming to light in Scotland - have sparked huge interest in the country's energy sector and alarmed green groups.

Tower Bridge's chief executive, American Helen Corey, insisted her floating systems were every bit as safe as the traditional fixed power plants they are designed to both replace and supplement.

She said: "These are purposely-built barges. We think they are nice to look at.

"The power industry has moved on to provide a lot of generation from a small unit."

The Herald this weekend revealed that National Grid was looking at proposals for floating capacity as an alternative to keeping the either the Longannet and Peterhead power stations open.

Ms Corey was tight-lipped over whether her company was bidding for that contract to provide stop-gap voltage support to Scotland.

Some 260 jobs at Longannet, in Fife, are riding on the decision, which is understood to be imminent.

Longannet - and its rival station in Peterhead - are both said to be facing challenging economics thanks to high connection and transmission fees imposed by National Grid.

Scottish Power had hoped to replace its giant coal-burning plant at Longannet with a smaller gas-fired one.

The kind of barges proposed by Ms Corey would have to pay fees too but could be moved elsewhere in the UK or overseas if market conditions did not suit.

Friends of the Earth is nervous about floating stations - although they are widely-used for emergency power supplies in the third world.

Ms Corey stressed her barges would be secured in ports, not bobbing about in the sea.

Declining to be specific about locations, she said: "We would consider a safe harbour port, so they would be held within the port itself."

Asked how her equipment would stand up to Scottish weather, she said: "I don't see how something raining on my barge would be any more concerning that something raining on a building on land."

Tower Bridge Ventures does not have any barges yet. Ms Corey admitted her firm had been operating under the radar. It expects them to come on stream in 2016.

Ms Corey said her power ships would burn liquid natural gas and that, ultimately, this could come from renewable bio-fuel.

Her pitch is that barges do not use up greenfield sites; are easily moveable and adaptable and provide localised solutions to capacity problems in the grid. Her firm is also looking at providing capacity in England and Wales - although less than in Scotland.

Scottish energy sources are not impressed. One said: "It's ironic this firm is called Tower Bridge because there is no way it would be allowed to park one of its barges on the Thames."

When asked about power barges, National Grid declined to comment on what its third option was.

A spokesman said: "We have received three proposals, which are currently being assessed."

Mike Calviou, director of transmission network service at the National Grid, last week told Holyrood's Economy, Energy and Tourism Committee that a decision would be made within weeks.

Richard Dixon, director, Friends of the Earth Scotland, said: "Any way you look at this, floating power plants are a stupid option.

"This is supposed to guarantee the security of the electricity supply in Scotland but power plants on ships are vulnerable to storms."