Light Pollution in Brookfield

Light Pollution in Brookfield

Summary

The Plan Commission had proposed a change to the type of lighting allowed outside of buildings. A resident called Alderman Berg and stated his opposition to the proposal. Alderman Berg did his own research, found several areas of concern with the proposed ordinance, and had the proposal sent back to committee. This is one of many examples that display Alderman Berg's willingness to listen to his residents, do his homework and take the lead in dealing with an issue.

At the Council meeting of October 1, 2002, a revised illumination ordinance was passed. This ordinance did not ban sodium lights, allowing a full selection of energy efficient options. The ordinance kept the original desireable clauses specifying cut-off shields, timers on parking lot lights, restrictions on pole heights, etc. Once again, Alderman Berg delivered for his residents.

At the Council meeting of February 15, 2005, a public hearing was held to reconsider this prohibition on sodium lights. Ald. Berg spoke against it, citing the same argument he made two years before.

At the Council meeting of March 1, 2005, the modifications were adopted. Sodium lights are still allowed and commercial lighting is more restricted.

During the debate of February 15, 2005, Ald. Berg made several arguments against the change. This is a follow up email Ald. Berg sent out the next morning.

Mayor & Aldermen -

I want to clarify a couple of points that I made last night regarding the proposed prohibition of sodium lighting in Brookfield.

I see this issue as trying to achieve a public good by balancing between an artistic goal, being environmentally responsible and government intrusion.

Artistic Goal - Sodium lights are a bright orange-yellow. The human eye is built for sunlight, which has a much wider spectrum of colors.

Some people think the pure yellow of low pressure sodium lights makes buildings "look funny" when illuminated compared to their natural sunlit appearance. I think we should keep in mind that the "natural" appearance of buildings at night is black. One way to measure this quality of light is the Color Rendering Index (CRI) which compares the spectrum against sunlight (zero is the worst, 100 is sunlight, you want something over 70).

Environmentally Responsible - The articles included at the end of this note from the federal Department of Energy are helpful. Note the energy efficiency comments. Of particular interest is that there are two types of sodium lights - the traditional low pressure sodium (CRI of 0) and the newer high pressure sodium (CRI up to 75).

By outlawing all sodium lights, the city would be forcing a greater use of electricity and a higher cost of operation. Is forcing the use of less efficient lights environmentally responsible? Is forcing the cost of operation in Brookfield consistent with being " *the* address for business"?

Government Intrusion - As a conservative, I believe the job of a legislator is to achieve public good through the minimal use of regulation, allowing the maximum freedom. The plan commission clearly has a role to manage traffic, flooding, etc. for safety goals. They have a role to manage density, building size, etc. to preserve neighborhood property values. But do they really need to pick out the color of the light bulbs? This issue is as much a test of Brookfield's community values limiting big government as it is about architectural artistic values.

The attached "halide_lights.pdf" from the DOE gives a favorable treatment of metal halide lights, although it does mention their tendency to explode, raining glass and molten metal below.

http://www.eere.energy.gov/buildings/appliance_standards/commercial/pdfs/hid_lamps/houghton_2002.pdf

If you really want to get into it, GE has a great set of color graphs (they really show the difference between sodium and sunlight) at:

http://www.gelighting.com/na/business_lighting/education_resources/learn_about_light/

Scott A. Berg

Alderman, 5th District

http://www.eere.energy.gov/buildings/info/components/lighting/lamps/lowpressure.html

U.S. Department of Energy - Energy Efficiency and Renewable Energy Building Technologies Program Low-Pressure Sodium Lamps

Low-pressure sodium lamps—producing up to 180 lumens per watt—have the highest efficacy of all commercially available lighting sources.

Even though they emit a yellow light, a low-pressure sodium lamp shouldn't be confused with a standard high-pressure sodium lamp—a high- intensity discharge lamp. Low-pressure sodium lamps operate much like a fluorescent lamp and require a ballast. The lamps are also physically large—about 4-feet long for the 180-watt size—so light distribution from fixtures is less controllable. There is a brief warm-up period for the lamp to reach full brightness.

With a CRI of 0, low-pressure sodium lamps are used where color rendition is not important but energy efficiency is. They're commonly used for outdoor, roadway, parking lot, and pathway lighting. Low- pressure sodium lamps are preferred around astronomical observatories because the yellow light can be filtered out of the random light surrounding the telescope.

http://www.eere.energy.gov/buildings/info/components/lighting/lamps/highintensity.html

U.S. Department of Energy - Energy Efficiency and Renewable Energy Building Technologies Program High-Intensity Discharge Lamps

Compared to fluorescent and incandescent lamps, high-intensity discharge (HID) lamps produce a large quantity of light in a small package.

HID lamps produce light by striking an electrical arc across tungsten electrodes housed inside a specially designed inner glass tube. This tube is filled with both gas and metals. The gas aids in the starting of the lamps. Then, the metals produce the light once they are heated to a point of evaporation. Like fluorescent lamps, HID lamps require a ballast to start and maintain their operation.

Types of HID lamps include mercury vapor (CRI range 15-55), metal halide (CRI range 65-80), and high-pressure sodium (CRI range 22-75).

Mercury vapor lamps, which originally produced a bluish-green light, were the first commercially available HID lamps. Today, they are also available in a color corrected, whiter light. But they are still often being replaced by the newer, more efficient high-pressure sodium and metal halide lamps. Standard high-pressure sodium lamps have the highest efficacy of all HID lamps, but they produce a yellowish light.

High-pressure sodium lamps that produce a whiter light are now available, but efficiency is somewhat sacrificed. Metal halide lamps are less efficient but produce an even whiter, more natural light.

Colored metal halide lamps are also available.

HID lamps are typically used when high levels of light are required over large areas and when energy efficiency and/or long life are desired. These areas include gymnasiums, large public areas, warehouses, outdoor activity areas, roadways, parking lots, and pathways. More recently, however, HID sources, especially metal halide, have been used in small retail and residential environments.

One of the reasons that Brookfield doesn't have the same "out in the country" feel that it used to is that there are so many outdoor lights. Spotlights on stores, floodlights in parking lots, streetlamps on many roads, etc. all add to the "citified" feel. To deal with this problem, the city staff and Plan Commission studied the issue and proposed an ordinance that limited the brightness, placement and type of outdoor illumination allowed in the city. The proposal was sent to the Council for approval.

Have you seen all that incredibly tiny print in the back of the Brookfield News advertising the ordinances when they are under consideration? Well, some residents actually read them. Fifth District resident Mark Ewert called Alderman Berg after reading the proposed lighting ordinance and said that he felt it was bad legislation. Specifically, Mr. Ewert pointed out that the ordinance would ban the use of sodium lights, which are the most efficient and lowest cost to operate.

Alderman Berg did some homework and decided that Mr. Ewert was correct. In fact, there were some other weaknesses with the proposed ordinance as well. Alderman Berg took action.

The following section is a copy of a memo that Alderman Berg handed out to all Alderman at the meeting when the ordinance was considered. After some debate, Alderman Berg moved for the ordinance to be tabled and sent back to committee for revision. The motion was passed unanimously, showing the other Alderman's agreement with Alderman Berg's lead.

The second following section is a copy of an e-mail that Alderman Berg sent to Chief of Staff Dean Marquardt outlining the Alderman's suggestions for improvements to the ordinance. Once again, Alderman Berg didn't just ignore the resident and didn't just throw a wrench into the works. Alderman Berg took a leadership role in guiding the writing of the ordinance to be better.

The illumination ordinance is now under revision by the staff and will be considered at an upcoming Plan Commission meeting.

A memo from Alderman Berg to the Common Council regarding the proposed illumination ordinance at the meeting of December 4, 2001.

To: Brookfield City Council

Date: December 4, 2001

Re: Proposed Changes to Illumination Standard

Tonight we will be considering a revision to the City of Brookfield’s Illumination Standard, section 17.120.70. Frankly I had not paid much attention to this change in the standard because I am not a member of the committees that drafted it. However, I had a letter from a resident, Mr. Mark Ewert, 3240 Nassau Drive, 790-9791, in which he raised the issue of energy efficiency. After a little research, I decided that Mr. Ewert has a point.

First, the proposed changes limit the size of a light to 400 watts. That is an inappropriate way of measuring a light since brightness is measured in lumens and the efficiency of converting watts to lumens varies greatly with the lighting technology. For example, a 400-watt incandescent lamp emits about 5,600 lumens across a wide spectrum of colors while a 220-watt total sodium light emits 33,000 lumens. That is, for half the power you get five times the light for an efficiency gain of ten times! I recommend that the ordinance be rewritten to limit the number of lumens and possibly consider the spectral characteristics of the lamp.

Second, the proposed changes would prohibit the use of sodium vapor lights. As the previous example and the attached chart shows, a sodium lamp is much more energy efficient then either a mercury or metal halide lamp. I think that’s way too large a sacrifice in energy for whatever subjective gain in appearance is achieved. I recommend that sodium light be allowed due to this energy efficiency.

I ask that this vote be sent back to committee for further study to decide if the amount of electricity the revised city code will be forcing to be wasted is worth the slight gain in aesthetics.

Regards,

Scott A. Berg

Alderman, 5^th District