Outdoor Lighting: Safety & Savings
Light Up the Night
Outdoor lighting presents a unique problem: there are few walls and no ceilings to reflect light back to your eyes. However, there are outdoor lighting solutions that can get the brightness you want while saving you money. One way to improve your outdoor lighting is to aim and position your lighting fixtures on buildings or other exterior surfaces (low gloss or rough surfaces minimize glare).
Bulb Basics: About Efficiency
Compact fluorescent bulbs (“CFLs”) in enclosed fixtures are often used for porch or post top lights, small area lighting, or wherever low lighting is enough to meet your needs.For large open areas, IR halogen PAR flood lamps are the most efficient sources. Halogen lamps can be up to 50% more efficient than standard incandescent lights. Halogen PAR flood lamps are more efficient than standard PAR flood lamps.
HID: Light With Might
High intensity discharge lamps are efficient, very bright and illuminate the darkest corners. High intensity discharge lamps are efficient, bright and work well outside. They use 75% to 90% less energy than incandescents and last up to 24,000 hours. Metal halide HID lamps are able to light large areas for extended time periods. High-pressure sodium lamps are more efficient than metal halide, but emit a yellow light and have poor color rendering. Mercury lamps are less efficient than metal halide lamps, need time to warm up and reach full intensity, and require special ballasts.
|Types of High-Intensity Discharge Lamps|
|Efficacy (lumens per watt)||Lifetime (hours)||Color Rendering Index||Color Temperature (K)|
|Mercury Vapor||25-60||16,000-24,000||50 (poor to fair)||3200-7000 (warm to cold)|
|Metal Halide||70-115||5,000-20,000||70 (fair)||3700 (cold)|
|High-Pressure Sodium||50-140||16,000-24,000||25 (poor)||2100 (warm)|
*Source: Department of Energy, Energy Efficiency and Renewable Energy, “Energy Savers: High-Intensity Discharge Lighting.” (July 19, 2011)
Solar powered landscape and walk lights are convenient, attractive and a popular choice amongst homeowners. They are easy to install and require no wiring. Take note: Since solar powered lights may not fully charge on cloudy days, they may fade or disappear during the night.
Floodlights mounted high on buildings are one way to efficiently light a large area. Remember to position your floodlights carefully so as to ensure they don’t shine into neighbors’ windows or property.
Controls & Sensors
There are controls available for outdoor lighting similar to those for indoor lighting. For example, motion-sensor detectors can be installed for security lighting which turn lamps on when motion is sensed. If you prefer to leave your lights on throughout the night, you may want to consider integrated photocells that will turn them off once daylight returns.
Find More Info
- American Council for Energy Efficient Economy
- California Energy Commission
- Energy Guide Home Analyzer & Energy Calculators
- Home Energy Advisor
- Department of Energy Home Energy Saver
- Our Energy Centers
- Rensselaer Lighting Research Center