Lighting
Lighting technologies and equipment have advanced significantly in the past few years, especially in terms of energy efficiency. The electricity sector is a large source of carbon emissions. By adopting energy efficient technologies, Maryland can reduce its carbon footprint.
Background
Lighting Technologies
Traditional lighting technologies, such as incandescent and fluorescent lamps, no longer provide the best value. About 90% of the electricity consumed by traditional incandescent lamps produces heat instead of illumination.
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Light-emitting diode (LED) lamps are as efficient as CFLs, last about 25-35 times longer than incandescent lamps, require less maintenance, and are mercury-free, unlike CFLs.
Ballasts control the starting and operating voltages of fluorescent and HID (high intensity discharge) lamps.
Magnetic ballasts used with fluorescent light fixtures prior to 1979 contain polychlorinated biphenyls (PCBs) and have to be disposed as hazardous waste.
Electronic (high-frequency) ballasts are cost-effective, 12% more efficient than magnetic ballasts, and eliminate flicker and hum. The most energy-efficient instant-start and programmed rapid-start electronic ballasts can be used with LEDs.
Preventing Light Pollution and Encouraging Energy Savings
Research indicates that intrusive night lighting might interfere with circadian rhythms in humans, reducing the production of the hormone melatonin, and thereby negatively affecting sleep. It may also disrupt the migrating, feeding and breeding habits of many wildlife species.
The International Dark-Sky
Association estimates that the U.S. uses 120 terawatt hours of energy for outdoor
lighting annually, with at least 30% wasted (e.g., unshielded lights). This
amounts to $3.3 billion and 21 million tons of carbon emissions.
- Choose fixtures that direct the light to the area needing illumination. Fixtures should be "full-cut off" or "fully shielded". Excessive, stray or misdirected light from exterior fixtures might cause unsafe glare, trespass over property lines, and contribute to "light pollution” and unnatural "sky glow".
- Choose lights with motion or occupancy sensors, controls, dimmers or timers that provide visibility and security while saving energy by turning off when not in use.
- Fluorescent, induction and light-emitting diode (LED) lighting sources work better with occupancy sensors and dimmers than traditional high-intensity discharge (HID) lighting sources and have the same, or longer, life spans.
- Avoid "Dusk-to-dawn" sensors without a middle of the night shut off control.
- Lamps should provide no more than the maximum light level (lumens per square foot) for adequate visibility.
Light Utilization Best Practices:
- Exterior lighting should be used for safe pedestrian passage and property identification. It should only be lit during active business hours when there is not enough daylight and then shut off afterward.
- Security and police should be notified of the “lights out” policy so that illumination and activity after hours can be investigated. For areas with cold winters, lamps should be rated for extreme temperatures of 0° F and less.
