* Denmark's Vestas to build 1st stealth turbines in France
* New blades use surface coatings inspired by warplanes
* Vestas studying export potential of the new technology
* Growing tensions between French army and wind industry
By Marion Douet
PARIS, Sept 5 France is building the world's
first wind farm with turbine blades designed to minimise
interference with radar systems, using technology partially
inspired by stealth warplanes.
EDF Energies Nouvelles, the renewables unit of
state-controlled utility EDF, aims to install the new
Vestas-built turbines next spring in the "Ensemble Eolien
Catalan" wind farm near Perpignan and start operating them over
the course of 2015.
"It is a world premiere for this new technology," an EDF EN
The turbines will account for the entire 96 megawatts of
capacity, which she said would make it the biggest wind farm in
Around the world, dozens of wind farm projects have been
blocked or delayed because of potential radar interference,
which can mask the signals of other objects. Turbine makers have
put years of research into radar signature reduction, most of
which is still in the experimental stage.
Denmark's Vestas, the world's largest maker of
land-based wind turbines, said the new blades would have a
smaller radar signature.
"We have used surface treatment technologies, including
those derived from military applications," said Nicolas Wolff,
head of the Danish firm's French unit.
Radar-evading jets such as the Lockheed Martin F-117
Nighthawk use a combination of shapes, angled surfaces and
radar-absorbing coatings to mask their "radar cross section", a
measure of the extent to which they are detectable by radar.
Wolff said that Vestas needed one or two more years of
research to study the potential for exporting the technology and
that Britain and the United States were possible markets.
TENSIONS WITH ARMY
EDF EN had tested the new technology on two turbines in a
wind park in Auvergne, in central France.
In France, close to 6,000 MW of wind farm projects have been
blocked because of fear of interference with military or weather
radar, French Windfarm Federation (FEE) said.
"There is a conflict here; there are two kinds of users for
the same space. For us, it is a real problem," said FEE director
The French air force has traditionally had a strong presence
in the skies at home. Military interventions in Libya, Mali and
Central African Republic in recent years have increased training
needs at a time when France's wind farm investment is catching
up with a renewable energy boom in Europe.
The French army must be consulted about any wind farms
planned within 30 km of its radar stations, and is putting up
more resistance to new projects, given that the newest turbines
can be as tall as 150 metres.
The defence and energy ministries, asked for comment, did
not respond. They are set to hold joint discussions over the
issue later this year.
The defence ministry told parliament in a July statement
that it needed to ensure "sufficient capacity" for its warplanes
to fly at low altitudes, both for defence and training missions.
(Writing by Geert De Clercq; editing by Jane Baird)