LED Street Lights
Benefits of LED Street Lights
There are many benefits to LED street lights over traditional high pressure sodium lamps including an approximate 50% savings in energy consumption, lower operating and maintenance costs, longer life span, and no warm-up period. Another advantage to LED lights is the ability to control of the color temperature, direction, and intensity of the light beam. In residential neighborhoods, this reduces light pollution in the sky and the need for residents to buy heavy window covers to block the light from entering houses. Smart LED light fixtures can also use motion detection to turn the light on and off on demand.
Proper Color Temperature for LED Street Lights
LED street lights come in a variety of color temperatures, measured in kelvins (K). The chosen color temperature of an LED light fixture is an important factor in the safety and health of residents and wildlife. Daylight produces a blueish (cool) white light that measures around 6500-K. While it may seem ideal to use such a high temperature light to improve nighttime sight, the use of bluer light LEDs can cause serious issues for the environment.
Studies have shown that the blue light in cool white LED lights can impact plants and animals, including humans. The blue light disrupts sleep patterns and movements and increases disability glare for drivers at night. This disruption can lead to a multitude of health issues, including death. According to the American Medical Association, the use of LED lights over 3,000K is harmful to humans and should not be used in street lighting applications. Blue light also travels further, so the use of cool white LEDs can increase light pollution. Many cities that have installed street lights with 4,000-K LEDs have had to cover the expense to replace the lights with new heads that used 3,000K LEDs due to a large number of resident complaints. However, some recent studies have indicated that the use of 4000-K LEDs provides a 20% increase in driver safety when used on main roads such as highways.
Residential areas are served best from the use of LED lights in the 2200-K to 2700-K range. LEDs with a color temperature of 2700-K are a close proximity to standard incandescent bulbs and cause minimal side effects and are pleasing to most people's eyes. 3000-K LEDs should be the maximum temperature installed in outdoor spaces. This range of color temperatures produces a warm white light that is safe for humans and animals and recommended by both the International Dark Sky Association and American Medical Association. For comparison, the traditional high pressure sodium lights measure about 2100-K and have a distinctive yellowish orange look. Those needing to illuminate sensitive habitats should use LED fixtures around 1800-K to reduce environmental impacts.