Lighting Costs Significant in Warehouses

Lighting is one of the greatest contributors to monthly utility bills in manufacturing plants, says Joseph Wolfsberger, senior vice president of environment, health and safety at Eaton Corp. But manufacturers can reduce energy needs and control costs through assessments and planning, he says. Eaton, a diversified manufacturer and provider of energy solutions, has counseled customers on ways they can save money through lighting control.

One of the first steps Wolfsberger recommends manufacturers take when assessing their lighting needs is to understand their current lighting situation and utility cost. He suggests conducting an inventory of lighting in the facility, taking note of the quantity, mounting height and type of lighting. Then observe the light quality. Some light sources, such as high-pressure sodium, cast a colored light that is dingy and makes it difficult to read or distinguish color, he says. A light meter can be useful for taking candle readings to determine how much light is available. Obtaining copies of maintenance records and utility bills also can help manufacturers calculate maintenance savings with a new lighting design later on in the process, Wolfsberger says.


Experts say T8 industrial strip fixtures, such as the ones used in this warehouse, can help manufacturers save on energy costs.
Manufacturers need to understand the processes occurring within their plants because different activities may have specific lighting needs. For instance, distinguishing differences in a product might require more light than forklift aisles, Wolfsberger points out. "We find that many factories with lighting that is more than 15 years old are over-lit when looking at the amount of needed light," Wolfsberger says.

Plan Your Retrofit. After examining the processes in place, use Illuminating Engineering Society (www.iesna.org) standards to determine target foot-candle light levels in different areas of the plant, Wolfsberger says. If possible, try using the existing wiring circuits to save time and money. Work areas should have more light than general ambient or aisle areas. Light levels will be more consistent over the life of the lamps with the new T8 or T5 lamps because they don't have the same lamp-life depreciation as metal halide or high-pressure sodium lamps, according to Wolfsberger.

The days of using high-intensity discharge (HID) lighting are over, says Steve Bellwoar, president of Colonial Electric Supply in King of Prussia, Pa. Industrial users should have already migrated to fluorescent low bays, he says. Linear fluorescent lighting in either a T5 high-output (HO) or T8 configuration is the best technology for reducing energy costs, says Larry Rodger, outside sales specialist for Synergy Electrical Sales Inc. in Fairless Hills, Pa. T5HO lights emit 5,000 lumens at 54 watts, while T8 lights put out 2,850 lumens at 32 watts. One of the most obvious ways to reduce energy usage in industrial lighting applications is by cutting the overall wattage consumption of existing fixtures, Rodger says. Many plants still use 400-watt HID fixtures or even some 1,000-watt versions in some higher ceiling applications. "A good rule of thumb is, if it's round, it must come down," Rodger says.

Understand the Costs. After selecting fixtures, determine the return on investment first by comparing the current fixtures' wattage and hours to the design fixture wattages and hours, Wolfsberger says. New lamps last longer than old lamps, so maintenance costs should be lowered and factored into the ROI. Reductions also will be realized in warmer climates that require a lower number of cooling hours with more energy-efficient lighting, Wolfsberger says. Another factor to take into consideration is lifecycle cost.

Some systems may be cheaper because they require fewer fixtures or other variables, but the optimal value will come from looking at the cost of the solutions over the life of the fixtures, says Wolfsberger. "You may find that the cost of and frequency of repairs, as well as energy cost differences may make a significant difference in total cost of ownership," he says.