One of Britain's largest green energy companies has damned the MoD as being “biggest single obstacle to wind power in the UK” after it opposed a second Norfolk wind farm.

One of Britain's largest green energy companies has damned the MoD as being “biggest single obstacle to wind power in the UK” after it opposed a second Norfolk wind farm.

The future of wind energy in the county was thrown into doubt last night after it emerged that the MoD has raised concerns over Ecotricity's plans for six turbines between Sporle and Swaffham.

It comes just a month after MoD objections scuppered three proposed turbines outside Hethel, near Wymondham, because of fears over the “national security” risk posed by their effect on military defence radar at Trimingham on the north Norfolk coast.

The MoD latest concerns again relate to rotating turbine blades masking aircraft and over objects by showing up on the radar at Trimingham, RAF Marham and RAF Lakenheath.

Ecotricity managing director Dale Vince told the EDP: “The MoD need to get their act together, they are the biggest single obstacle to wind energy in the UK, after local councils of course.

“Too often the MoD make unspecific objections, late in the planning process - it's a kind of stalling tactic.

“Breckland Council could have been firmer with MoD, this application is six months past the date when a decision should have been issued.”

Ecotricity maintains that the radar system at Trimingham is due to be replaced in 2008, removing the issue with the turbines, and that the MoD has not substantiated its objections.

The MoD says that trials conducted in 2004 and 2005 on the effects of wind turbines on radar systems identified that even solitary turbines can significantly reduce operational effectiveness when in line of sight.

Experts say the MoD now objects to about 50pc of applications to build onshore wind turbines.

A MoD spokesman said: “It is crucial that the MoD is able to maintain necessary radar coverage for a safe military air traffic control service (which is provided to both military and civilian pilots), for effective air defence of the United Kingdom, and to protect airspace used for vital low level flying training.”

He said the MoD had concerns about the 120m tall turbines at Sporle since October 2005 and had been talking to Ecotricity since it made its concerns known to them in January 2006.

The MoD will submit its formal response to Breckland following a detailed technical assessment of the proposed turbines, which would have a 12MW total output, ahead of the plans being decided on December 17.

Chris Tomlinson, director of programme strategy at the British Wind Energy Association said he hoped it could be resolved: “In a wider sense we all work on the same agenda: wind power will have a crucial role in ensuring security of power supply, which again is a strategic issue of national security.”