While there are many benefits to LED streetlights, there are some downsides too. They only provide directional light, so they can't produce a spherical "glow" emanating in all directions, like most lights. Because of this feature, they are generally used in streetlights that are hanging or facing downward, rather than in lamp-type lights. Still, they are considered well-suited to outdoor applications and some people have appreciated the directional light, as it doesn't cause streetlights to shine into homes or create light pollution by shining light into the sky where it's not needed.
The initial cost of LED lighting is high, and consequently, it can take several years for the cost difference to be made up through cheaper energy bills. An LED streetlight costs around $1,000, while standard lights cost $250 each. Similarly, a 60-watt fluorescent bulb for a home lamp can be purchased for $1, with a similar compact fluorescent bulb costing around $2. But an LED bulb, produced by Phillips and designed for home use, costs $107. The high cost derives in part from the material used: LEDs are often made on sapphire or other expensive substances.
Some users have been disappointed in the brightness of LEDs. But new technological developments have LEDs closer to producing classic bright white light. Eventually, LEDs are expected to be able to produce all colors of the spectrum, but for now, they are generally limited to red, yellow, green (hence their use in traffic lights), blue and a white that bears a slight blue tint [source: Britt].
While cities are trying to think long-term and, in the United States, seeking stimulus money to help fund LED streetlight conversions, the cost may be prohibitive for some municipalities. In light of the recession, some cities are turning off existing streetlights to save on electrical bills. Others are looking into adding motion sensors that activate streetlights only when pedestrians are detected.
Finally, some experts think that though many cities are interested in LED streetlights, the greatest barrier to widespread adoption of the technology may simply be education [source: McClear]. Many people are unaware of the many uses of solid-state lighting, as LEDs are classified, and that high initial costs can lead to long-term savings. But with companies like Phillips investing millions in research and development and clamoring for valuable municipal contracts, LED streetlights certainly have a bright future.
For more information about LED streetlights and other related topics, please look over the links below.
Related HowStuffWorks Articles
- Britt, Robert Roy. "Bright Future: LEDs Revolutionize Lighting." Live Science. Dec. 17, 2008. http://www.livescience.com/technology/081217-led-lights.html
- Cohen, Stephanie I. "Holiday lighting gets an energy-efficient upgrade." Market Watch. Dec. 9, 2007. http://www.marketwatch.com/story/holiday-lighting-gets-an-energy-efficient-upgrade
- Galbraith, Kate. "To Save Energy, Cities Darken Street Lights." New York Times. Sept. 26, 2008. http://greeninc.blogs.nytimes.com/2008/09/26/to-save-energy-cities-darken-street-lights/
- Keen, Judy. "More cities tap stimulus package for LED streetlights." USA Today. March 3, 2009. http://www.usatoday.com/news/nation/2009-03-02-streetlights_N.htm
- Rosenthal, Elisabeth and Barringer, Felicity. "Green Promise Seen in Switch to LED Lighting." New York Times. May 29, 2009. http://www.nytimes.com/2009/05/30/science/earth/30degrees.html
- Taub, Eric A. "Fans of L.E.D.'s Say This Bulb's Time Has Come." New York Times. July 28, 2008. http://www.nytimes.com/2008/07/28/technology/28led.html
- "Brainstorm: Solid-State Lighting Adoption." ECNmag.com. June 1, 2009. http://www.ecnmag.com/article-Brainstorm-Solid-State-Lighting-Adoption-060109.aspx?menuid=334
- "Portugal begins switch to LED street lamps." Greenbang. April 21, 2009. http://www.greenbang.com/portugal-begins-switch-to-led-street-lamps/