Hawaii could be considered Earth’s clearest window to the universe. Thanks to dark night skies offered by the vast surrounding Pacific Ocean and Hawaii County’s strict lighting ordinance, Mauna Kea peak is home to the world’s largest astronomical observatory used by astronomers from 11 different nations.

Even so, since the dawn of the electrical age, artificial light has threatened to obscure Hawaii’s night skies—and to disrupt the life cycles of its rare wildlife.

Fledgling seabirds drawn to lights have circled until exhausted, then dropped from the sky and become prey for feral mongooses and cats. Newly hatched sea turtles drawn to illuminated park restrooms are also easy prey. Those able to make it to the ocean are often too tired to survive the surf.

 Dark nesting areas and wild habitats have been lost. Insects swarming around light poles have caused feeding frenzies that upset the delicate food web.

With all its natural wonder, Hawaii lays bare the consequences of light pollution. Which is why last February, it served as the perfect location for considering ways to mitigate it.

Along with the International Dark Sky Association, IES Honolulu Section and Hawaii Energy, the DesignLights Consortium (DLC) presented “Impacts of Outdoor Lighting: Considerations to Reduce Energy, Save Money and Minimize Light Pollution for People and the Environment.”

DLC is a nonprofit that collaborates with utilities, energy-efficiency programs, manufacturers, lighting designers, building owners and government entities to create rigorous criteria for lighting performance.

Members of the audience, both in-person and online, discovered plenty can be done to reduce the impacts of outdoor lighting. They also learned benefits for animals and humans in terms of health, reductions in energy use and cost savings.

Leora Radetsky, DLC senior lighting scientist, suggested several strategies:

• Use outdoor lighting that is dimmable and control-ready to enable end-users to meet local energy codes and save energy beyond code requirements.
• Consult local ordinances and regulations, as well as lighting practitioners, community members and local experts regarding effects on humans and animals.
• Use only the right amount of light to support activities and provide visual comfort.
• Install controls and detectors so light is applied only when needed.
• Make sure only areas that need illumination are lit, such as pathways and walkways—rather than lighting grassy or beach areas.
• Program lighting controls to change with the seasons to avoid using light during seasonal migration or breeding periods.
• Minimize use of blue and violet light, which scatters further in the atmosphere and is more likely to disrupt animals’ life cycles. Choose fixtures with a lower CT (equal to or less than 3,000K).
• Use amber or red LEDs with minimal blue wavelengths in areas close to observatories and in environmentally sensitive areas, with guidance from local experts to provide input as to which lighting spectrum is best.
• Research lighting choices before purchase and ask for spectral power distributions. The DLC’s LUNA Qualified Products List contains products that have gone through third-party vetting for light mitigation and other performance criteria. Products also qualify for utility energy-efficiency program rebates in many states.

  The presentation followed its own advice as far as consulting local experts. Presenters included an astronomer, a program manager for the U.S. Fish and Wildlife Service and a representative from Hawaii Energy, a ratepayer-funded energy conservation and efficiency program administered by Leidos Engineering LLC under contract with the Hawaii Public Utilities Commission.

For tackling the problem of light pollution, Graceson Ghen, Hawaii County manager for Hawaii Energy, suggested committing to additional changes as technology improves.

Hawaii introduced LEDs in 2008. “The unavailability of low-pressure sodium fixtures, combined with the potential for energy and maintenance cost savings, drove the conversion,” Ghen said.

Hawaii County had to address the higher levels of blue light associated with LEDs and their associated effects on astronomy and wildlife.

“By 2017, Hawaii converted all streetlights to LED with less than 2% blue light,” he said.

Header image: Waikoloa Village rests not far from Mauna Kea peak in Hawaii, home to the world’s largest astronomical observatory. Thanks to new amber LED street lighting, the popular tourist destination has reduced blue light refraction and preserved ultimate nighttime viewing for the observatory. The change also has reduced impacts to local wildlife. Photo supplied by C&W Energy Solutions LLC.