Highlights—
- A model for quantifying light pollution from wind turbine lights is proposed.
- Brightness of lights from wind turbines can far exceed that of the brightest stars.
- The visual range of wind farms at night is generally larger than at daytime.
- A study of the visual impact at night of four prospective windfarms is presented.
- The model proposed may be used in environmental impact and landscape assessments.
ABSTRACT—
Wind farm lights are a conspicuous feature in the nocturnal landscape. Their presence is a source of light pollution for residents and the environment, severely disrupting in some places the aesthetic, cultural, and scientific values of the pristine starry skies. In this work we present a simple model for quantifying the visual impact of individual wind turbine lights, based on the comparison of their brightness with the brightness of wellknown night sky objects. The model includes atmospheric and visual variables, and for typical parameters it shows that medium-intensity turbine lights can be brighter than Venus up to ~4 km from the turbine, brighter than α CMa (the brightest star on the nighttime sky) until about ~10 km, and reach the standard stellar visibility limit for the unaided eye (mv = +6.00) at ~38 km. These results suggest that the visual range of wind farms at nighttime may be significantly larger than at daytime, a factor that should be taken into account in environmental impact assessments.
Salvador Bará, Former profesor titular (retired) at Universidade de Santiago de Compostela (USC), Galicia, Spain
Raul C․ Lima, Física, Escola Superior de Saúde, Politécnico do Porto, and Instituto de Astrofísica e Ciências do Espaço, Univ Coimbra, Portugal
Journal of Quantitative Spectroscopy and Radiative Transfer, Volume 329, December 2024, 109203
doi: 10.1016/j.jqsrt.2024.109203
Quantifying the visual impact of wind farm lights on the nocturnal landscape