The engine at Wansbeck General Hospital, at Ashington, Northumberland has been out of service for two years because of a fault.

The news comes on the back of previous stories highlighting faults with turbines at Blyth and Kirkheaton, which left them inactive for long periods. Critics of wind power last night said the new revelation is further proof turbines are an unreliable source of electricity.

The 23.4 metre tall 100 kilowatt turbine was erected in 1992, a year ahead of the opening of the ‘low energy' hospital.

It was intended to produce one tenth of the hospital's energy and to power its wards and operating theatres.

But information provided to The Journal shows the turbine has produced no electricity since 2007.

The engine has not been operational because a fault developed on the tip of one of its blades, whereby its carbon fibre coating started to come loose.

The fault was repaired but later reappeared and the turbine was switched off.

Northumbria Healthcare NHS Foundation Trust, which owns the hospital, said it has commissioned an external report to look into the feasibility of repairing and re-commissioning the structure or, if not practical, alternative uses to which it could be put.

Last night, Dennis Grieve, of Front Street, Newbiggin by the Sea, said the fault with the turbine comes as no surprise.

The 62-year-old, who used to work in the electronics industry making microcircuits for Welwyn Components at Bedlington, wrote to The Journal in 2006 about the two offshore turbines at Blyth which were not working after a blade was hit by lightning.

He said: "When they break down, they (the wind farm industry) do not really like to publicise it.

"You see these turbines all the time, people are saying we must have turbines, the whole point of it is when you go home and you switch the lights on you expect the electricity to be there and if you had to rely on these things, you are up a gum tree really."

The trust's report will consider repair costs, ongoing maintenance and operations costs if the turbine is brought back into long-term service, and how long the machine has left to run.

Brian Griggs, director of estates and facilities at Northumbria Healthcare NHS Foundation Trust, said: "The turbine has been in service since 1992 and has produced an average of 140,000 KWs of electricity per year, approximately 18% of the electricity consumed by the hospital.

"It produced no electricity during 2008/2009 due to a fault on the tip of one of the blades. This was due to the delamination of the tip material. This was repaired, however, the repair failed some time later and rotation was stopped for safety reasons.

"We have commissioned the New and Renewable Energy Centre to produce a report which will look into the feasibility of repairing the turbine or, if this is not possible, explore alternative options."