A Green plan to install wind turbines on rooftops has been called into doubt by a report suggesting they may not only damage houses but are also

incapable of saving the planet.

Environmentalists in Brighton and Hove came up with a plan to fund dozens of turbines to provide heating and lighting to homes across the city.

The proposals were given serious consideration by councillors and energy experts in the city.

However, a study commissioned by Building For Future, a specialist sustainable construction journal, suggests such devices could be plagued by technical problems and seldom generate significant energy, especially in urban areas. More worryingly, they could be ripped off in heavy winds, pull down chimneys or damage rooftops.

The Argus reported in February how the Green Party on Brighton and Hove City Council had tabled an amendment to the council's budget proposing that a £200,000 fund be set aside to help people install turbines and other renewable energy equipment in their homes.

It lost by one vote but all parties on the council are still keen to pursue and promote sustainable energy.

However, Nick Martin, a green building techniques expert, said in one paper: "The lateral thrust exerted by these turbines on a Victorian chimney stack in a high wind would be more than sufficient to topple it."

Mr Martin also said the energy output from the turbines had been vastly overestimated, adding: "I can tell you now that for the average house in the UK a roof mounted wind turbine will not provide anywhere near your electrical power requirements.

"Nor will they save you £400 per year in electricity bills."

In another study Derek Taylor, director of the Milton Keynes energy agency and principal partner of Altechnica, an environmentally-friendly architectural practice, reported that some homeowners had been forced to deactivate turbines because of the vibration they caused.

But a third report by John Shore, of Somerset company Aerodyn Windturbine Systems, said wind power offered one of the most reliable and efficient forms of renewable energy for Britain.

Green Party leader Keith Taylor said the reported problems could be overcome and were no reason to turn away from wind power. He said: "These findings need to be listened to and we must make sure that we are not creating one problem by trying to solve another.

"But wind is the most dependable source of renewable energy and we have to use our best endeavours to harness its power."

Colin Barden, director of renewable energy engineering company Eclectic Energy, said new models were overcoming many of the technical problems.