The Department of Conservation and Natural Resources released a study recently by an internationally respected lighting consultant that indicates a proposed wind farm near Cherry Springs State Park in Potter County will have an unnoticeable impact on the dark sky viewing opportunities.

“DCNR has the responsibility to protect the irreplaceable dark skies of Cherry Springs State Park—a facility that has garnered national attention for the quality of its astronomical viewing opportunities,” DCNR Secretary Michael DiBerardinis said. “After consulting with the International Dark Sky Association, we sought this review to understand what the impacts of this proposal might be, and to identify any mitigation measures that might be desirable or possible.”

DCNR chose Clanton and Associates of Boulder, Colorado, to do the study based on the recommendation of the International Dark Sky Association. The company used a conservative analytical method to estimate the worst case skyglow impact from the federally required lights on the proposed Headwaters Wind Energy wind turbines.

In addition to determining the project’s impact would be unnoticeable, the study said there would be “very minimal if any” line of site impact from the Cherry Springs observation field. Clanton and Associates also identified some outdoor lighting fixtures at the nearby Denton Hill State Park that could be adjusted and some opportunities on other public and private properties in the area that if achieved, would make the dark skies even darker.

DCNR contracted to do the study after the Pennsylvania Outdoor Lighting Council and numerous astronomy enthusiasts contacted the department when the project was first announced.

Project developer AES has been very cooperative and responsive during the review. The company retained its own lighting consultant and shared detailed project information and its own analysis with DCNR’s consultants. The project is undergoing local and permitting reviews.

A copy of the Clanton report is available online.

6/20/2008