* Vestas says successfully tests "radar-friendly" turbine
* Says tests show 99 pct reduction in radar reflection
* Says tests are a step towards commercialisation
By John Acher
COPENHAGEN, June 29 Wind turbines that do not
interfere with radar systems used by aircraft may soon become a
commercially viable option for the wind energy industry, Danish
turbine manufacturer Vestas said on Wednesday.
"Our testing has demonstrated that we have successfully
adapted military stealth technology to make Vestas wind turbines
viable for placement in many locations that have been restricted
by radar concerns," Vestas Technology R&D President Finn Strom
Madsen said in a statement.
Vestas said it successfully tested in Britain a full-scale
"stealth" rotor on a turbine, paving the way for wind power
plants to be located near military installations, airports and
other radar systems without interfering with their operations.
Stealth technology was initially developed by the U.S.
military starting in the late 1950s to prevent radar tracking of
spy planes and is currently used in the Northrop Grumman B-2
Spirit "Stealth Bomber".
Stealth turbines are made with radar-absorbing materials,
which can almost entirely eliminate the reflection of radar
waves off the turbine, Vestas said.
"This is a critical step toward the commercialisation of
stealth turbines and holds potential to open a significant
number of wind power locations for Vestas customers," Madsen
An estimated 20 gigawatts of wind power capacity is
currently blocked worldwide by concerns about radar
interference, Vestas said.
Vestas presented test results at the International Wind and
Radar Forum in Ottawa, Canada, showing that a Vestas turbine
with a stealth rotor achieved a targeted reduction in radar
reflection of about 99 percent compared with standard turbines.
"This means that when the radar waves strike the
stealth-treated turbines, only 1 percent is reflected back,"
Jeffrey Awalt, a Vestas R&D spokesman, told Reuters.
Vestas has been working on stealth turbines with its British
technology partner QinetiQ since 2006.
"At this point, this is not something we have on the
market," Awalt said.
"We do expect that this will develop into a commercial
product," he said, but added that it was not possible to say
when the technology could be marketed.
"We haven't determined exactly what the cost will be, but we
don't expect that it will be a significant additional cost for
the turbine," Awalt said.
(Editing by Will Waterman)