Wasted light

Energy crisis illuminates the wastefulness of bright outdoor lighting

For more information on energy efficient lighting, see www.darksky.org
Lights dimmed around Sacramento last week as a conservation order took effect, ordering all retail businesses to cut their use of outdoor lighting during off hours.

Gov. Gray Davis may have hit a well-known sore spot among Sacramento residents who, while stumbling around in homes darkened to conserve energy, see auto dealers, shopping malls and the Money Store lit up like Strom Thurmond’s birthday cake.

But with Davis’ edict mandating a business to not exceed 20 percent of its energy capacity when the doors are closed, some questions have been raised about determining who could calculate that 20 percent amount and who could enforce the violations.

Law enforcement agencies are on record as saying they won’t become power police, and even Davis said last week, “I don’t think we’re going to have a need to write any tickets or citations” to the owners of bright businesses.

Sacramento Police Community Service Officer Tawnya Bump says she reviews all building plans during the permit process and sets conditions for outdoor lighting. These conditions reflect standards offered by the Illuminating Engineers Society of America.

“Very seldom have I put conditions [saying], ‘You must use this type of lighting,’ ” said Bump. “High-pressure sodium is most frequently used for outdoor lighting because of its efficiency and it’s what we’d generally recommend.”

More than an actual hammer hanging over business, the governor’s conservation order seems mostly intended to shine light on a broader problem: inefficient outdoor lighting wastes energy by sending light out into space.

Jack Sales is a member of the International Dark Sky Association (IDA). He says group members traditionally have sought passage of dark-sky ordinances in areas around observatories.

The focus of such ordinances is simple: keeping light pointed down toward the objects or locations that need illumination, rather than pointing it up and lighting the sky.

This goal can be accomplished through light poles that reach out over a street or building and shine down, through fixtures that use a cutoff piece to prevent light from shooting out above a 90-degree angle, or bulbs that promote long life instead of glare.

Illuminating objects rather than space implicitly boosts efficiency, says Sales, a Citrus Heights resident and spokesman for the California Chapter of the International Dark-Sky Association. What began as an effort to preserve the dark sky around observatories has turned into a national effort for energy efficiency, he says.

“It just makes sense. Why should we send all that light out to the sky when we need it down here?” Sales said. “There are advantages as far as energy conservation for cutoff lighting.”

The math is simple, say the dark-sky activists. If the public would accept a 25 percent adjustment of city light, it would see a 25 percent cut in its electricity bill, saving billions of dollars. The IDA estimates $2 billion a year is wasted in the United States on light that shines upward rather than downward, where it’s needed.

Sacramento is estimated to waste 14.9 million kilowatt-hours a year in light energy. That figure comes from Japanese astronomer Syuzo Isobe, who uses satellite photos of the Earth to tally the amount of light that travels upward from various locations. He then calculates the amount of electricity needed to produce this mostly wasted light.

The waste can come from street lights, traffic lights, residential outdoor lighting and building facade lighting. At current rates, one kilowatt for residential service ranges from 12 cents to 16 cents, according to Pacific Gas & Electric’s Web site. That means close to $2 million worth of energy is wasted annually through inefficient, misdirected outdoor lighting.

Four types of outdoor lighting are used, according to lighting designer Sean Darcy of Associated Lighting in Sacramento: high-pressure sodium, low-pressure sodium, mercury vapor and metal halide.

High-pressure sodium is becoming the standard for its efficiency and its ability to show colors. Low-pressure sodium, the most efficient, is known for not showing color—everything appears black—which could be an issue when trying to identify a person or a vehicle. Mercury vapor used to be the industry standard, says Darcy, but because energy efficiency is becoming fashionable, many manufacturers have been cutting back its production.

Most of Sacramento’s 30,000 street lights use high-pressure sodium lighting, with the average light bulb lasting about 24,000 hours, says Rick Matsuo, a supervising engineer in the city’s Public Works department.

A mercury vapor light averages about 10,000 hours. Traffic lights have cutoff pieces to prevent light from shining up or too far out. The city sports 90 different styles of lights.

The city and county both lack a standard specifying the amount of light that can shine upward, whether it be from street lights or the new Cal/EPA building. Matsuo says many older neighborhoods, such as Land Park and East Sacramento, still prefer decorative lighting—often an acorn-shaped fixture using mercury vapor lighting that shoots beams in all directions.

“We pretty much let the community have choices and a lot of them are wanting more ornamental lighting,” said Matsuo. “The project costs more and the lights require more maintenance.”

Tracking which type of lights are where in Sacramento presently is not possible. But a dark-sky ordinance could require that, says Sales.

When the city of Davis enacted its Dark Skies Ordinance several years ago, observers say it added to the town’s hippie reputation, pointing to the fact that conservationist Mayor Julie Partansky introduced the proposal.

Since the ordinance was enacted, all newly lighted outdoor areas have been outfitted with high-pressure sodium lighting, says Mike Goodison, assistant to the public works director. Now, the city is retrofitting a portion of its older lighting each year to install high-pressure sodium lighting and star-friendly fixtures.

“It’d be great if every metro area could retrofit its lights to be efficient and sky-friendly,” Goodison said, “but where’s the money going to come from?”