Substitutes for Sodium Bulbs

Sodium bulbs are often found in parking lot light fixtures.

Outdoor lamps that produce light with a yellow-orange color along highways or in parking lots use low-pressure sodium bulbs. Low-pressure sodium bulbs are considered the most energy efficient lights, but their color rendition limits their use. High-pressure sodium lamps produce a more desirable golden color light, but they are not as efficient as low-pressure sodium lamps. Both lamps don’t come on instantly; they take some time to warm up. Two types of high-intensity-discharge lights successfully serve as substitutes for sodium bulbs. Two other types of lights may occasionally serve as substitutes.

Mercury Vapor Lamps

Mercury vapor lamps cast a blue/green white light. Their use is often limited to street lighting because of their fair to poor color rendition. They last longer than metal halide lamps, with a life expectancy similar to sodium lamps. As mercury vapor lamps reach about 60 months of use, they produce about 50 percent less light but use the same amount of energy. Therefore it pays to replace mercury vapor lamps as they age.

Metal Halide Lamps

Metal halide lamps produce a desirable bright, white light. They have a variety of uses including lighting gyms, sports arenas and other large indoor areas. Because of their good color rendition, metal halide bulbs are used outside in car lots, athletic fields and other areas where color is important. They are favored for security because it is easier to identify people and vehicles under this type of light. Metal halide lamps have a shorter life expectancy than sodium lights.

Fluorescent Lights

Fluorescent lights may serve as a substitute for sodium lamps in some situations. The primary drawback to fluorescent lamps is their poor performance in cool weather. They are better suited for offices, classrooms and other indoor uses.

LED

Light Emitting Diodes are energy efficient; they have a very long life expectancy. They instantly turn on and off and have a desirable color rendition. However, LED lights are relatively expensive. With new technology, LED lights may replace some sodium lights in the future.

References

• U.S. Department of Energy: Low-Pressure Sodium Lighting
• Marietta Power and Water: Outdoor Lighting
• Kansas State University; Energy Conservation and Renewable Energy; Lighting and Appliances: Lighting
• Edison Tech Center: Sodium Lamp
• Energy Guide: Small Business Guide: Larger Opportunities: Lighting

Resources

• OKSolar: LED for Street and Parking Lot Lighting Applications