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www.illinoislighting.org presentation, August, 2008 Click to begin.

Www.illinoislighting.org presentation, August, 2008 Click to begin

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www.illinoislighting.org presentation, August, 2008 Click to begin. Slide 2 PERPETUAL TWILIGHT: Our Careless Destruction of the Night, And How To Reverse It Slide 3 PERPETUAL TWILIGHT: Our Careless Destruction of the Night, And How To Reverse It Presented by the Illinois Coalition for Responsible Outdoor Lighting 2008 www.illinoislighting.org Slide 4 More than 80% of Americans live in urban areas. Urban areas which tend to be dominated by manmade light. Slide 5 Since earliest times, humans have tried to create light, to drive back the frightening dark. Slide 6 But modern technology has allowed us to take the light of a few campfires, and multiply it billions of times over. Slide 7 Our primitive fears of the dark, and our headstrong drive to extend our daytime activities, has led us to the point where our nighttime is flooded with light. Slide 8 Star-filled skies, which inspired countless generations Slide 9 Star-filled skies, which inspired countless generations have faded to pale, endless twilight. Slide 10 Star-filled skies, which inspired countless generations have faded to pale, endless twilight. Will our children, or theirs, ever witness the magnificence of the universe above them? Slide 11 A daily cycle of light and dark has provided a pulse to living organisms on Earth since life appeared eons ago. Slide 12 Our human bodies retain important internal functions regulated by the day/night cycle, too. Slide 13 But manmade light at night can disturb natural cycles, harming both our world and ourselves. Slide 14 Equally disturbing is the amount of energy we consume to light our world, Slide 15 Equally disturbing is the amount of energy we consume to light our world, and the percentage of that energy which is wasted. Manmade light shining from North America, imaged from high Earth orbit. Slide 16 Equally disturbing is the amount of energy we consume to light our world, and the percentage of that energy which is wasted. Relative nighttime sky brightness over North America. Slide 17 If we intend to light up areas on the ground, so we can be active at night, why is so much light shining up into our skies? Relative nighttime sky brightness over North America. Slide 18 The electricity consumed to light the skies over our nation to this level equals the total output of dozens of generating plants running at full power. Relative nighttime sky brightness over North America. Slide 19 Add in the light which shines in other directions, outside of the areas we intend to illuminate, and the energy waste from poor lighting is staggering. Relative nighttime sky brightness over North America. Slide 20 And the waste goes on, hour after hour after hour, Relative nighttime sky brightness over North America. night,after night,after night Slide 21 Where does the waste come from? Slide 22 From operating lights when theyre not needed From over-illuminating And the most common source, From poorly engineered lighting fixtures Slide 23 Where does the waste come from? From operating lights when theyre not needed (Example: Lights left on all night) From over-illuminating (Example: City park with overly- redundant light placement) And the most common source, From poorly engineered lighting fixtures (Example: Mall lot lights sending as much of their output in sideways glare as in downwards illumination) Slide 24 How can we remedy the situation? Slide 25 Answer: Use light fixtures which put the light only where it is needed. Many common fixtures send their light output to places other than where theyre meant to illuminate. Slide 26 Answer: Use light fixtures which put the light only where it is needed. Many common fixtures send their light output to places other than where theyre meant to illuminate. This directly wastes a large percentage of the energy, and can create hazardous, unsightly glare. Slide 27 Answer: Use light fixtures which put the light only where it is needed. Wasteful torch fixturesDownward focused fixtures Slide 28 Answer: Use light fixtures which put the light only where it is needed. Hanging fixturesRecessed fixtures Slide 29 Answer: Use light fixtures which put the light only where it is needed. Globe-top fixturesDownward focused fixtures Slide 30 Answer: Use light fixtures which put the light only where it is needed. If all of a fixtures light output is focused on the area to be illuminated, a lower wattage lamp can be used than is needed in a wasteful fixture. Energy use can be cut tremendously, and much harmful stray light eliminated. 63% ENERGY WASTE FROM ACORN-TOP FIXTURES Slide 31 Answer: Use light fixtures which put the light only where it is needed. But we can see the direct glare from this light, and others all the way down the street, because they wastefully send their output where it isnt needed. The green lines indicate the zone which this street lamp is intended to illuminate. Slide 32 Answer: Illuminate only to the levels needed. When it comes to nighttime lighting, more isnt necessarily better. It can just mean more power consumption, and more glare. Chicagoland at night from Earth orbit. Years after the City of Chicago completed its massive installation of thousands of new street and alley lights to combat crime, the Citys own studies found no resulting decrease in street crime. Slide 33 Answer: Operate lighting only when needed. Much outdoor lighting serves the needs of activities which do not take place over the entire night. By shutting of lighting during non-use hours, or reducing it to safety/security levels, tremendous energy savings can be achieved. Auto dealer with all lot lights on after closingAuto dealer with lights down to security level after closing Slide 34 The future is up to us to shape. Slide 35 Lets make responsible decisions. Slide 36 end photo credits: U.S. Defense Meteorological Satellite Program U.S. nighttime lights, from data collected 1994-1995 World Atlas of Artificial Sky Brightness Istituto di Scienza e Tecnologia dell'Inquinamento Luminoso U.S. nighttime lights, derived from DMSP data (above) NASA Earth Observatory Chicagoland at night, photographed from the International Space Station, October 2003 All other photos & graphics: Illinois Coalition for Responsible Outdoor Lighting www.illinoislighting.org, all rights reserved.