EoW November 2010

EuroWire – November 2010

Transat lant ic Cable

Energy

Air power meets wind power – and a

formerly blameless green-energy

technology comes under suspicion

Scepticism of e orts to generate electricity from wind power

tends to centre on unreliability (when the wind dies down, so

does the windmill) and unsightliness: no vista, onshore or o ,

is enhanced by a“wind farm”of steel turbines with vanes as tall as

400 feet. No one has been heard to impugn the virtue of a non-

polluting technology which seeks to reap value from a renewable

source free to all.

Until now, that is.

The United States Air Force asserts that moving wind turbine

blades can mimic airplanes on many radar systems and even

cause planes to disappear from radar screens altogether; also

that clusters of turbines can create false storm activity on weather

radar, making it harder for air tra c controllers to give accurate

weather information to pilots. Accordingly, the Air Force has

declared wind turbines a danger to its operations and called

for the removal of thousands of them now standing in the

Tehachapi Mountains that skirt the Mojave Desert in southern

California. Writing from Barstow, California, in the

New York Times

Leora Broydo Vestel pointed out that this indictment of wind

turbines has important support in Washington.

In March, Dr Dorothy Robyn, Deputy Under Secretary of

Defense (Installations and Environment), told a congressional

subcommittee that the turbines pose an unacceptable risk to

training, testing and national security in certain regions. While

the military has not ascribed any serious incidents to this cause,

the Defense Department has emerged as a strong opponent of

wind projects.

This stance puts Defense in direct opposition to another branch

of the federal government, the Energy Department, which is

spending billions on wind projects as part of President Barack

Obama’s e ort to promote renewable energy. Collisions between

military and industry have occurred elsewhere in the country

but appear to be most frequent in California and Nevada. There,

as noted by the

Times

, the Air Force, Army and Navy control

20,000 square miles of airspace and associated land used for

bomb tests; low-altitude, high-speed air manoeuvres; and radar

testing and development.

The impact of wind turbines on radar, which the

Times

said “had

been a back-burner concern for years,” is now very much to the

forefront for rms in the Mojave area thwarted by opposition

from the military to wind-powered electrical generators.

Ms Broydo Vestel wrote, “Horizon Wind Energy recently withdrew

three project applications. AES Wind Generation said it found

out in May, after nine years of planning, that the military had

objections to its proposal to build an 82.5-megawatt, 33-turbine

wind farm.” (“Wind Turbine Projects Run Into Resistance,”

August). According to the AmericanWind Energy Association,

in 2009 about 9,000 megawatts of proposed wind projects were

abandoned or delayed because of radar concerns raised by the

military and the Federal Aviation Administration.

From the results of a member survey by the Washington-based

trade group, that is nearly asmuch as the amount of wind capacity

that was actually built in the same year.

Eliminating turbine clutter on radar is challenging. Ms Broydo

❈

Vestel observed that many radar systems in use in the United

States date back to the 1950s and have outmoded processing

capabilities – “in some cases, less than those of a modern

laptop computer.” She wrote, “While there are technology

xes to ease interference on these aging systems, it can be

tricky to lter out just the turbines.” Gary Seifert characterises

the radar-wind energy clash as “the train wreck of the 2000s.”

The researcher with the Idaho National Laboratory, an Energy

Department facility, told the

Times

, “The train wreck is the

competing resources for two needs: energy security and

national security.”

Canadian advances in mobile robotics

enable safer and more economical

inspection of overhead power lines

Canada is quietly carving out a speciality in the use of industrial

robots for the inspection of overhead high-voltage transmission

lines, an operation ordinarily (and expensively) performed

from a helicopter, through binoculars. Canadian utilities are

experimenting with line-crawling robots to monitor aging

1970s-era transmission infrastructure for wear and tear and other

hazardous conditions. (Let it be remembered that an overhanging

tree branch triggered the massive Northeast Blackout of 2003.)

An article in the

Toronto

Star

reported on the midsummer

inspection of transmission lines crossing the St Lawrence

River. “Each 735-kilovolt line carries a powerful punch,” wrote

Tyler Hamilton. “So getting close enough to these live wires can

be tricky – and potentially deadly if mistakes are made.”

But not for the two robots engaged in the inspection project

overseen by Hydro-Québec, a provincial utility and one of the

biggest electricity producers in North America. A typical stint for

the robots, on the job for two weeks to that point, was ve to

sixhours aday, duringwhicheachof them inspectedsix kilometres

of line.

(“A High-Wire Act for Robots,” 1

August)

The battery-powered LineScout – in use by developer Hydro-

Québec since 2006 and by BC Hydro [an electric utility in the

province of British Columbia] since 2008 – overcame the inability

of an earlier model to move past transmission towers and hop

onto and o di erent lines. It is waterproof, equipped with four

cameras, packed with sensors that can detect such problems

as corrosion, and capable of working in extreme temperatures.

As described by Mr Hamilton, it hangs from the line “like a

mechanical sloth on roller skates.”

Serge Montambault, a manager of the St Lawrence crossings

project, told the

Star

that inspection used to require that “hot”

transmission lines be de-energised – disconnected temporarily

from the grid. But rising demand for electricity argues against

taking lines out of service. Now, he said, “They can send the

robot to do the live-line inspection, bring back high-quality

images and data, then let an engineer on the ground decide if

repairs are necessary.”