The Pros, Cons of Solar, Wind

The FAA Tech Center’s Jim Patterson gives an update on the pros and cons of solar, wind technology.

He points out that one of the “downfalls” of self-contained LED units is again the battery, which generally gives way before other parts of the units fail.

Wind Turbines

Wind presents different challenges, says Patterson. The noise of the units is one; another is location, or siting.

“The first thing that comes to mind is the interference with airborne radar, and that could be anything from the radar that’s looking for airborne aircraft or with aircraft on the ground at the airport with ground surveillance systems,” he explains. “You have to be really careful; these turbines create a lot of noise and disturbance with airborne radar; the radar picks up different signals from the turbine as it’s rotating and as it changes its orientation to align with the wind. It’s constantly changing and there’s just no way of isolating that noise that the radar is picking up.”

There are also concerns about obstruction lighting, he says — if a lot of turbines are planned, there could be a situation with obstruction lights.He says that several years ago FAA completed an in-depth study at 14 wind turbine farms to see how they were being lit. “After doing our tour of the country and seeing all of these different sites,” he says “we were able to develop a good, safe configuration for lighting these wind turbine farms. As a result we were able to greatly reduce the number of lights that were required.”

FAA built a test site at Lawton, OK at the Blue Canyon Wind Farm, called the largest of its kind, which had 43 turbines. “We lit just a few at key locations and [today] 13 of the 43 turbines actually have lights on them,” he says. “We required that they all blink at the same time, so the pilot has the feel that it’s a farm — not just a bunch of wind turbines but a large area to avoid as a hazard.”

Another concern is the impact of wind turbines on wildlife, particularly birds. Reducing the number of lights can help make the turbines less attractive to the birds, says Patterson.

“The other big thing with wind turbines would be siting. The majority of turbine designs are very tall — upwards of 200 feet tall. We’re looking at new ones coming out that will be over 500 feet tall. Tall turbines create some issues with object-free zones and imaginary surfaces that we need to keep clean for arriving and departing aircraft.”

That said, he points out that Boston Logan International recently installed some 20 six-foot high wind turbines atop an administration building to harness the energy coming off the adjacent bay. “It was kind of a perfect-sized turbine to lend itself for an airport application,” he comments.

Master Plans

All these considerations, says Patterson, can be taken into account for future master planning. “Limitations on the technology and siting issues are something that airports can work into their master plans to make them more sustainable,” he suggests.

“If I had a favorite it’s probably solar just because we don’t have rotating blades that we have to hide from our radar facilities. There’s always that chance new technology will come out and wind turbines will become more airport-friendly. There’s always that chance.

“We have several research efforts to address that. One is a localized radar system, a sensor, that we can put at the wind turbine that would actually provide radar coverage in that immediate area. There’s a chance that we can take that radar feed and feed it back to the FAA’s airport radar and, between the two communicating, they would be able to eliminate or filter out that noise being created by the turbine, and actually give us full coverage without interference.”

He adds that there’s also work underway with the Military Academy at West Point trying to develop a stealth wind turbine that couldn’t be detected by radar. “If that came forward it would be earth-shattering,” he says. “It would definitely make wind more compatible and something an airport could put in its master plan.”

Future Guidance from FAA

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