July 11, 2019
Pennsylvania

Ice throw and shadow flicker, focus of wind farm testimony

By Seth Isenberg | Times News | July 10. 2019 | www.tnonline.com

The end of the Broad Mountain Power’s presentations was set for Aug. 14 at the Packer Township Zoning Hearing Board’s eighth hearing on Broad Mountain’s proposed wind turbine farm atop Broad Mountain, held Monday night.

The balloon flying test will be attempted on July 20, 21 or 22, likely near sunrise when the wind conditions are lightest. The exact date and time will be announced on BMP’s Facebook page – BroadMountainWind; or on their website – broadmountainwindproject.com where you can also register for email updates. The four balloons, each about 12 feet in diameter, once up will remain up about an hour and a half (in the right conditions). Once up, a full set of photos will be taken from the sites previously listed, plus a few new ones, including one in the Lake Hauto development. If those dates don’t work out, the test will be rescheduled.

The evening’s expert was York University professor Dr. Jim Salmon, president of Zephyr North of Burlington, Ontario, Canada, who explained icing on wind turbine blades, and how the blades can throw ice. He also went over the ice protocol where the affected turbine would shut down when ice makes the blades unbalanced, then restart after 30 minutes. After a second shutdown, the technician on call would need to go to the site to check the unit.

Salmon estimated, based on local weather data, an average of seven ice days a year.

On ice days, some pieces may be thrown as much as 800 feet onto the wind farm property (not out beyond it) likely onto the project’s private roads – as many as 100 pieces of ice per turbine.

Packer Township attorney Robert Yurchak quipped, “Avoid the area on icy days.” He also noted that the manufacturer, Siemens Gamesa, recommends a site-specific review.

Salmon explained further that, during an ice detection protocol, ice would drop down to the base of the shut units.

Zoning Hearing Board member Myron Tarapchak and zoning board attorney and meeting leader Greg Mousseau asked questions about the size of the ice chunks as they leave the blades. Salmon did not have an answer.

Attorney Bruce Anders, representing a group of residents opposed to the project, questioned Dr. Salmon’s estimate of ice days based upon weather data from the valleys in Wilkes-Barre and Allentown. Anders noted 1994 had 16 icing days. After some back and forth, there were no further questions for Dr. Salmon.

The next expert on the stand was Ryan Pohle of Schoener Environmental, Dickson City, who was back to explain his shadow flicker mapping results.

Anders, during his questioning, asked if the removal of trees to install the units would affect shadow flicker. Pohle answered it would “at the site.”

He asked about shadow flicker caused by moonlight. Pohle had no answer. Anders asked about the effect of shadow flicker on people driving cars or tractors. He wrapped up by asking Pohle if he had done any “post-report testing,” and Pohle replied he had not.

Mousseau asked if the blades were shorter, would there be less shadow flicker? Yes was the answer.

Frank Tiano, of Lake Hauto, was recognized. He asked Pohle about his reliance on the Wind Pro software. Pohle explained Wind Pro had the largest use worldwide for this kind of modeling, and is kept current with the changes to wind turbines, as new units are getting much bigger. As a summary of other questions, it was stated that shadow flicker increased with blade speed, and the bigger towers with their big blades turn slower.

Attendance was around 80 people, about 10% from Nesquehoning, a few from the Jim Thorpe area, and most of the rest from Packer and Weatherly borough.

Hearings are next on July 16 and 22, then Aug. 7 and 14, all starting at 6 p.m. at the Weatherly Area Middle School Cafeteria.


URL to article:  https://www.wind-watch.org/news/2019/07/11/ice-throw-and-shadow-flicker-focus-of-wind-farm-testimony/