The issue was first raised in 2004 by Météo France, the national meteorological service, when it started installing new, more powerful radars and noticed increased clutter in the vicinity of turbines. The defence forces and the civil aviation authorities began to take note and last year all three bodies recommended a 30 kilometre exclusion zone around radar as a precautionary measure pending further studies.
While details of radar belonging to Météo France and the civil aviation authorities are public knowledge, the number and location of defence radar is largely unknown. The wind industry has gradually been piecing together a picture, however. SER estimates that there are around 90 radar stations in France and that the combined exclusion zones cover pretty much the whole country.
The situation is confused by the fact that the exclusion zone is not compulsory and has no legal basis. Instead, the defence forces only have authority to advise the prefects, the state appointed officials who have the final say in the wind plant permitting process, not to approve turbines within the zone until it is known if there really is a problem. This means that some prefects have approved projects within the "prohibited" area, particularly where turbines are not in the line of sight of the radar. In the majority of cases, however, projects have been put on hold.
At the same time, a number of turbines are already operating less than 30 kilometres from a radar station, apparently without causing any problems up to now. Indeed, Jean-François Petit of the French Wind Energy Association (FEE) says that up to last year there was no problem with radar and the industry has never been shown any evidence of interference. "Is noise really a problem?" he asks."We need to have this discussion."
The air force says it has asked radar manufacturers to assess how much interference turbines create and to suggest solutions, although the results may not be available for another six months. In addition, Météo France and the civil aviation authorities have been carrying out their own studies. But Antolini argues that the industry ministry should set up independent and comprehensive trials in order to satisfy all sides. He also points to the situation in the UK, where the defence authorities are now moving away from broad exclusion zones having accepted that flexible technological and software solutions exist (Windpower Monthly, November 2005).
The situation may become clearer in early April when the industry ministry, wind industry representatives and the three radar operators meet to discuss the problem. In general, says Petit, the industry has a good relationship with the military and he is optimistic a solution can be found. The important thing, argues Antolini, is that the issue is either resolved or that there are clear and reasonable regulations. "You can't have a target of 9000-10,000 MW of installed wind power and then one day someone wakes up and says you can't install turbines in France because of the radars," he says.