Bob Parks, Executive Director Smart Outdoor Lighting Alliance March 5, 2015
Anthropogenic or man-made Artificial; not natural Occurring during natural dark cycle Natural night brightness varies due to moon phase cycle ( lux at zenith) WHAT IS LIGHT AT NIGHT?
18.7% of Earth’s surface is subject to artificial brightness of 10% or more above natural 61.8% of the United States 75% of US population lives under unnatural levels of LAN LAN in major cities is typically 100 to 200 times brighter than a natural night sky LIGHT AT NIGHT STATISTICS
LAN creates winners and losers Attracts and repels Disrupts: Foraging Predation Migration Reproduction Communication ECOLOGICAL IMPACT OF LAN JP Stanley
Disruption of foraging patterns Increases predation risk Increases mortality on roads Bats fly farther and use more energy to avoid lights Reduces body weight and reproduction in females MAMMALS
Disrupts natural cycles of reproductive and migration Birds fly into lighted buildings Off-shore drilling platforms & towers lighting causes significant attraction Hydrocarbon flares attract and incinerate night flying seabirds BIRDS
Artificial light contributes to an estimated 10 to 40 million bird deaths annually in the United States alone. BIRDS Jim Richardson
Diurnal (day) species extend activity and exploit prey attracted to lights Light attracts breeding frogs, who stop calling LAN has profound impacts on physiology, behavior and development REPTILES & AMPHIBIANS
Reduces nesting habitat – Females avoid areas near lighted beaches Hatching disorientation – Crawl towards area with brightest horizon Which can often be roads or lighted development Exhaustion/dehydration Increases mortality Increases predation SEA TURTLES Jelga
Fun Fact: Great White sharks have now learned to hunt seals at night using city lights! FISH
Most attracted to white light Increases mortality at street lights Confuses species that use light for communication (Fireflies) Interferes with normal migration Aquatic invertebrates – disrupts behavior and increases predation risk INVERTEBRATES
PLANTS Affects: Germination Leaf growth Flower development Fruit development Leaf senescence Abscission Cessation of leaf production
Circadian Disruption LAN disrupts immune system – suppresses melatonin – affects all species of animals and plants Linked to insomnia, obesity, diabetes, ADD, and cancer Photo ganglion cells have peak sensitivity ~480nm (Blue) ECOLOGICAL IMPACT OF LAN Jim Richardson
Broad Spectrum White Light White LEDs start as blue Highest CCD LED is the most efficacious and have the most blue spectral power distribution (SPD) White light improves visibility However, improvement in visibility drops off above 3500K CCT ECOLOGICAL IMPACT OF LAN
Broad Spectrum White Light Efficacy vs. Ecological impact As LED efficacy improves, compromise will become easier Generally, use lowest CCD to minimize impact; however… SPD & melanopic lux is best metric Minimizing total lumens in the environment more important ECOLOGICAL IMPACT OF LAN
LED SPECTRUM 5500 K CCT
LED SPECTRUM 2700 K CCT
Properly Shielded Fixtures Direct light to the task area Reduce skyglow and light trespass Light for Visibility Use just the illumination levels necessary for the task Eliminate glare Reducing uniformity may improve visibility by increasing contrast BEST PRACTICES FOR ECOLOGICALLY RESPONSIBLE OUTDOOR LIGHTING
Adaptive Controls: Allows dimming to match pedestrian/vehicle traffic illumination requirements Employ timers/switches to turn off lighting when no longer needed Increase energy savings by 50% + Reduce glare, energy costs and CO 2 Increase fixture life BEST PRACTICES FOR ECOLOGICALLY RESPONSIBLE OUTDOOR LIGHTING
Tvilight
Spectrum Narrow-band “true” amber and phosphor converted “PC” amber (~590nm) LEDs provide viable replacement for LPS PC amber LED has greater efficacy LPW than true amber LED at LPW “Turtle friendly” turns out to be best all around light source for ecologically sensitive areas BEST PRACTICES FOR ECOLOGICALLY RESPONSIBLE OUTDOOR LIGHTING
LED SPECTRUM PC Amber
Dynamic Spectral Tuning Arrays of different LEDs in fixture allow for programming a variety of correlated color temperature (CCT) over time Locally or remotely controlled Provide white light during peak activity hours for maximum visibility; smooth transition later to lower CCT BEST PRACTICES FOR ECOLOGICALLY RESPONSIBLE OUTDOOR LIGHTING
80% of outdoor lighting is used for Commercial & Public Exterior Lighting ~750 million Outdoor Lighting Fixtures* Worldwide ~160 million Outdoor Lighting Fixtures* in US *Commercial & Public Exterior (Road, Street, Parking + Buildings) WORLD OUTDOOR LIGHTING FACTS
Total Wasted Energy is approx % overall from: Unwarranted (not needed) = 25% Over-lighting (excessive illumination) = 25% Not dimmed or on curfew = 25% Glare =15% Uplight = 10% WORLD OUTDOOR LIGHTING FACTS
Approx. Wasted Energy = 1.1 PetaWatt Hours Annually The equivalent output of 500 power plants running 24/7/365 Could power ~ 7,750,000 homes Producing 750 million tons of CO2 Cost = approximately $110 billion (US dollars) WORLD OUTDOOR LIGHTING FACTS