John Denham MP, secretary of state, agreed with planning inspector Ruth MacKenzie that the surrounding hills and woodland would 'contain' the adverse visual effects of the scheme.

The decision letter from the secretary of state's office, sent out to interested parties on Thursday, stated: "Like the inspector, he considers that, despite the major landscape effects at close quarters, the containment of the site by hills and woodlands would prevent the significant effects of the proposal spreading more than about 1km from the site.

"He also agrees with the inspector that although in certain places and for some people the visual effects would be major, overall, they would be acceptable."

Andrew Joicey, a member of opposition group SOUL (Save Our Unspoilt Landscape), told the Advertiser that he was 'completely delighted' with the outcomes in relation to Moorsyde and Toft Hill, but said that it was 'extremely disappointing' that the secretary of state had not also turned down the Barmoor scheme.

He added: "As a group, SOUL are taking advice to see if there are any grounds for a challenge - on procedural grounds as there is not a right of appeal as such - but it is too early to say if this will be possible, but we need to explore it."

Mr Joicey is concerned that approval of the Barmoor scheme has opened the flood-gates for more applications in the area.

He said: "My fear, and that of many others, is that this is just the first six turbines to be consented in the area. I can see many more applications coming forward, and we may see the same as what happened in the Lammermuirs, which started off with 22 turbines but has grown to hundreds now.

"It is almost a free for all and it appears that planning control has almost broken down up there. It would be disastrous for north Northumberland if that was to happen here, and there is a danger that it will happen."

He added: "I can see applications coming forward almost anywhere within the 'broad area of least constraint' south and west of Berwick, and it is obvious that there is an expense attached to applying for a wind farm, but the reward is spectacular for successful wind farm investors.

As a result, they can pay rent to landowners that they have never seen before, which looks highly attractive to them."

Mr Joicey also commented on the intermittency of wind energy generation, stating that during the recent three weeks of severe weather, when the need for electricty rocketed, almost none was being produced by wind farms, as shown on the National Grid's website.

He concluded: "If, or when, these turbines get built at Barmoor, there will be a lot of people shocked to see how tall they are. People have no idea about the size of them or how they will look in this landscape."

Both the secretary of state and the planning inspector agreed that Ford Moss Colliery, a scheduled ancient monument with a Grade II listed chimney, would have its 'setting' changed, but not to an 'unacceptable degree' by the wind farm.

In fact, Mrs MacKenzie said in her report: "In my view, the juxtaposition of 17th century and 21st century examples of energy generation, about 1km apart, would add a new perspective to the colliery's historical interest."

The inspector also said: "The Northumberland National Park, the AONB (Area of Outstanding Natural Beauty) and the Heritage Coast are all at least 8km away and, to my mind, there would be only a negligible effect on their landscape character."

In terms of the impact of the turbines on nearby residents, Mrs MacKenzie stated: "According to SOUL, there would be 378 dwellings within 3km of the proposed wind farm. The nearest dwellings include "Barmoor Ridge" (720m away from the nearest turbine) and "Barmoor South Moor" (770m away from the nearest turbine). I have no doubt that the visual effect of the turbines from these, and many of the other dwellings within the 3km range, would be dramatic; but, to my mind, it would not be overwhelming.

"Barmoor Castle Country Park, and the many mobile homes within it, is surrounded by trees. In my opinion, these trees and the other areas of woodlands between the park and the proposed wind farm about 1.6km away, would significantly reduce the impact of the turbines on the visual amenities of those staying at the park," she added.

Mrs MacKenzie concluded that 'in certain places and for some people,' the visual impact of the six turbines would be 'major' but acceptable, and that the benefits of the scheme outweighed the harm it would cause.

David Butterworth, managing director of Force 9 Energy, told the Advertiser: "Obviously we welcome the decision from the secretary of state, and we are pleased that he has confirmed that Barmoor wind farm is well sited and well designed.

"We are looking forward to building it so it can make its contribution to the country's renewable energy sources."

The Barmoor planning application was first submitted in February 2006. It was originally for nine turbines but, in October 2007, the number was dropped to six turbines with a total installed capacity of up to 13.8MW.