Case History: Looking for Savings: Seeing the Light

Case History: Looking for Savings: Seeing the Light 2017-01-07T19:33:25+00:00
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Case Histories

Looking for Savings: Seeing the Light

by Richard V. Morse

Our nation’s departments of public works are under the gun to get the job done for as little as possible. Few days go by when DPW officials do not consciously consider activities or services they could somehow cut back or eliminate to make their budgets balance.

Energy reductions always are a principal concern. Energy consumption is associated with almost any service that DPW provides. Lighting often is targeted in various “save-a-watt” and similar campaigns, because it is such a conspicuous consumer of energy. Unfortunately, all too many people seem to forget that it is not the purpose of lighting to provide light. Instead, lighting’s purpose is to help people achieve various objectives; light is the medium through which the purpose is achieved. As such, any lighting system modification, be it to attain energy savings or for any other purpose, will affect lighting’s ability to do its job.

One of the best known examples of a “for the worse” situation occurred almost 20 years ago, when the Wisconsin Department of Transportation deactivated all lighting on 55 miles of Milwaukee-area freeways and 100 interchanges. Lights were kept off for 20 days, until widespread public concern caused the department to reverse its position.

Although the incident was not truly an experiment, it tended to be treated as such given the extremely important information that was derived. For example, data obtained from the October 1-20, 1980 “lights-off” period were compared with data derived from the same period in 1977, 1978, and 1979. Comparisons revealed that, during the 20-day period in 1980, reportable nighttime accidents increased 14 percent, interchange ramps accidents increased 35 percent, and the number of persons injured increased 50 percent.

Even more alarming data were derived by comparing the 20-day lights-off period in 1980 to the 20 days preceding it, September 10 to 30, 1980. That comparison indicated that, during October 1 to 20, the number of reportable nighttime accidents increased 129 percent, interchange ramp accidents rose 89 percent, the number of accidents with injuries increased 230 percent, and the number of persons injured increased 173 percent.

The Direct Cost?

From a lighting researcher’s point of view, it would have been worthwhile to know not just the societal cost imposed as a result of accidents, but also the direct cost to the city, for emergency response, accident clean-up, and repair of guardrails, roads, light poles, etc. Probably for every $1 in energy saved, an additional $10, $20, or more had to be spent due to the safety loss created by the lighting loss. A police official noted that the absence of lighting reduced security patrol productivity significantly, because police officers took longer to patrol due to the loss of visibility. They had to rely far more on vehicle-mounted spotlights. It was noted, too, that far more time had to be spent on sanding, salting, and plowing operations, because it was simply more difficult to see.

Studies conducted in the United Kingdom also point out lighting’s impact on the bottom line. During the winter of 1973-74, a number of local authorities complied with a national request to cut lighting levels by 50 percent, due to an energy shortage. Data showed that, in an area such as a Brighton (no pun intended!), thefts from vehicles increased by 59 percent and the number of break-ins increased by 100 percent. In Lancashire, vehicle thefts increased 13 percent, thefts from persons rose 25 percent, house break-ins increased 65 percent, and shop break-ins rose 66 percent.

A case history that took place much closer to home is also instructive, and encouraging. It involves the tiny ranch and farming town of Paragonah, UT. There, the city replaced twenty-two 400-watt mercury vapor lamps with twenty-two 150-watt high-pressure sodium (HPS) lamps. The cost of energy consumption fell from $2,313 annually to just $867; maintenance costs fell from $1,200 to 0. But that is not all. The town is so small it does not have its own police force. Instead, it obtains police services from the county and pays on a per-call basis. Once the new HPS lighting went in, the number of police calls dropped sharply, saving the town an additional $350 per year. In addition, town fathers reported, the main street was far safer for pedestrian and automotive traffic, because the additional lighting made everything much clearer.

In a San Diego case, Spring Valley Park invested $17,000 in new lighting that reduced vandalism, burglaries, and accidents to such an extent that the city’s investment paid for itself in about six months. Before the new lighting went in, the park experienced several serious incidents of assault with injuries each year, in addition to frequent parked auto break-ins. About 50 pedestrian-related accidents occurred annually, many involving senior citizens, along with some 40 vehicular accidents each year.

Another $10,000 had to be spent annually to clean graffiti from the community center, and another $25,000 was being lost each year due to theft and damages resulting from break-ins at the community center. Once the new lighting was installed, assaults and robberies were virtually eliminated; the number of pedestrian-related accidents fell from 50 to 12; vehicle accidents dropped to five or six, and vandalism and burglaries were virtually eliminated. The park has also become a much more functional facility, thanks to lighting that lets youngsters use playground areas after the sun goes down and increases participation in evening bingo games (along with increasing county revenue derived from a percentage of the bingo operator’s profits). All in all, about $32,500 per year was saved thanks to the $17,250 investment in better lighting.

First, Make it Better

Much of the lighting now in place, whether managed by a DPW or a sister agency, is out-of-date and consumes far more energy than necessary. Reducing energy consumption should not be the only objective when modernization is called for, however. Instead, every effort should be made to first make the lighting better, so it does more and thereby provides more benefit.

Achieving such benefits takes effective design. Experience indicates, however, that designers cannot be left on their own. They need guidance about exactly what it is an agency wants to achieve. To give that kind of guidance, you first need to know what the possibilities are. That is why the National Lighting Bureau was established more than 20 years ago.

The bureau is an educational organization sponsored by lighting manufacturers, national trade associations, and agencies of the federal government. They bureau promotes the concept of High-Benefit Lighting®, encouraging users to rely on lighting that helps attain the objectives for which it was installed. Once the ideal system has been designed from a functionality standpoint, the design can be refined and components can be specified such that energy consumption is kept to an absolute minimum. Putting energy efficiency ahead of function really does not make sense. In essence, a system that does not get its job done as well as it could wastes energy whenever it is used.

Richard Morse is Vice President, Marketing Communications, Lithonia Lighting, Conyers, Georgia, and Chairman of the National Lighting Bureau, Silver Spring, Maryland.

This article originally appeared in the October 1998 issue of Public Works®, published by Public Works Journal Corporation, 200 South Broad Street, Ridgewood, NJ 07450. ©1997 Public Works Journal Corporation. All rights reserved.