IESNAIDA Model Lighting Ordinance Part 1 The View

IESNA/IDA Model Lighting Ordinance Part 1: The View of an Astronomer Light Pollution and the IES Dan Caton

What we will look at… Why protect the sky? n The light pollution issue—a brief primer on sky glow, glare and light trespass n The need for design n A brief history of the MLO (and why I gave up on it…) n Eric Gibson does the numbers n

Light: our shared interest What you do What I do

Another shared interest

My Concern: ASU’s Dark Sky Observatory

100, 000 hobbyists

Everyman…

Just as important

Light Pollution: the loss of the night sky Light Pollution and the IES

The basic problem: Sky Glow n n Light from fixtures reflects off particles in the sky— ”Sky Glow. ” Large cities visible from tens of miles. The stars are not brighter in the country—the sky is darker! A worse problem here in the east, due to higher humidity levels than out west.

Our Global Problem

Light “Made in the USA” ~ 1 G$ / year of wasted

What’s Wrong With this Picture?

Closer to home You are here!

Boone ~ 40 years ago…

… today

Charlotte… Courtesy Spencer

Light Pollution Causes n n n Poor fixture design Lack of shielding Over-lighting Poor installation Market pressure Let’s look at a few specific problems

Floodlights n n n Almost horizontal No shielding At night …

Typical fast-food lighting • Discomfort glare, bordering on disability glare • Light trespass onto adjacent properties, roadway drivers • Contributes to sky glow

Better: Full Cut Off

Even Better! • Van Gogh’s Café Terrace at Night, 1888 • Experience at Tweetsie. • Result from California study: reduce glare and you can reduce the overall lighting level

Roadway lighting-overhead glare Majority of the”light budget”? (Note: MLO does not cover)

Sag-Lens Cobra heads n n Glaring to driver Light polluting

Better, FCO Fixtures n n n No light above horizon Non-glaring to drivers, too! May require more poles per mile—but could we get the DOT to specify FCO? Progress Energy uses on all new roadway now And at night …

Car Sales Lots n n n Often grossly overlit This one at 60 -110 Fc on lot, 65 on road Can be done nicely…

… like this (Tampa)

Wall Packs n n n One of the worst fixtures for pollution as well as glare (or even for its intended purpose!) Are available in FCO What is the point of these?

I will give you architecture Would be allowed under MLO…

Why shown in day?

Ever notice?

Bad area/security lighting

Health concerns n Baby sea turtles attracted to street light n Cancer and melatonin production in people

Solution: put a cap on it n New GE Sky. Gard shown here. Hubbell, too n Guaranteed to 100 mph, tested to 120 n Why not the default for new orders? n Reduce lamp wattage, with light saved

Gas Station Canopies This about 85 fc – several times IES RP

Sports lighting n n Often done poorly with lots of light pollution, light trespass, and glare (as baseball fans know). Can be done better as shown here, using fixtures like Musco’s shown here

The Model Lighting Ordinance n n n Began evolution circa 2000? Existing IDA Lighting Code Handbook long and tedious. Jim Benya’s paper at 2001 IDA Meeting, “A Proposal to Establish Inter-Organizational Standards for Outdoor Lighting. Let’s Do it!” MLO Working Group met at 2002 Tucson IDA Meeting and discussed basics, logistics. Hoped to roll out MLO 1. 0 at Fall 2002 Boston IDA meeting. Members were common with IESNA Outdoor Lighting Committee, chaired at that time by Nancy Clanton. Draft version (2004. 1) circulated, stirring controversies about closeness to industry, watts vs. lumens, lumens per acre, etc. MLO plods along today, cards held close. Based on lighting zones with different specifications for each. I have been less concerned since the MLO in any of its incarnations is too complicated for small communities like Boone. Besides, I was tired of waiting for it!

Small Town Approach: Boone n n n n n Commercial only, at this point. Go for light control as the main theme (FCO required). Floods allowed but must be shielded. Gas station canopies must meet 35 fc limit within 7 years. All other lighting grandfathered in but must be changed if renovated. Sports lighting must have light control package. Minimum/maximum table in footcandles (easy enforcement). Lighting plan required, including a 10' x 10' illuminance grid (point-by-point) of maintained footcandles overlaid on the site plan, which demonstrates compliance with lighting standards specified. Effective 1/1/2006. We will see how it works. Admitted problem with this approach: designers face different ordinances in different towns.

Summarizing n n n Light pollution almost always caused by luminaires and installation techniques that do not do their task well. We can all work toward better lighting and (thus) darker, starry skies. Ordinances should cause lighting to be designed which is good for all of us. Thank you for your time and attention. www. darksky. org and www. ncdarksky. org dan@caton. name www. dan. caton. name