The LED lighting industry has emerged in recent years with the aim of replacing the more common incandescent, compact florescent, halogen and other types of indoor and outdoor lights for the commercial and residential space. LED lights promise to be more efficient and lasting, but they also are more expensive. Inside each LED light bulb is a chip or a cluster of chips – light emitting diodes – that produce the illumination. LEDs have long been used to light up computer screens. Designing them to light up an entire room or shine a beam over a long distance is far more technically challenging and requires higher production costs.
A 60-watt incandescent bulb for a table-top lamp at home costs a few dollars. An LED light that delivers the same illumination costs around $25-$30, and that price is much lower than just a few years ago, when it was around $60.And you can get it with much lower price in original producer' s online shop,for example http://www.ledgrossiste.fr

LED lighting companies not only are working on reducing the prices but also educating consumers about the merit of paying more upfront for bulbs that will last much longer. Convincing store owners to pay more initially might be easier, since they tend to do more long-term, cost-and-benefit analyses of their investments. A good lighting system attracts more foot traffic and that can translate into more sales.
The technology at the center of the shift is the LED, or light-emitting diode. LEDs are a break from the history of illumination. As solid-state semiconductors, they’re more akin to the processor in your smartphone than the lamp overhead. Los Angeles, New York, Chicago, Shanghai, Copenhagen and scores of other cities around the world are deploying LEDs in an attempt to solve most, if not all, of the problems created by inefficient traditional lamps.
The social and economic gains from illuminating the night have been incalculable, but our future selves will look back with regret over the wasted energy and the damage done to the natural cycle of light and dark. Electric streetlights first began appearing in European capitals in the mid-1800s. Parisians and Londoners marveled at the light, even if it was so blinding the lights had to be installed in high towers. America pierced the darkness in April 1879, when the first electric lamp went up in Cleveland. Ever since it’s been an all-out race to illuminate every road, gas station, warehouse and corner of the country.
Today in the U.S. there are some 60 million of those cobrahead streetlamps blazing pink-peach all night long, heedless of inactivity below and absurdly lighting the sky above. Forty percent of the average city’s electric bill goes to street lighting, and close to half of that is wasted. Excessive outdoor lighting, including exterior fixtures on office and industrial buildings, wastes about $3.5 billion in energy per year, according to the International Dark-Sky Association, a not-for-profit that works to reduce light pollution. The number of truly dark places on Earth is shrinking rapidly. Upward light emissions have been growing at least 6% per year across North America, according to satellite images and computer modeling done by researchers at the National Park Service and research institutions in Italy and the U.S. Two-thirds of the world’s population, including 99% of those in the continental U.S. and Europe, no longer experience starry nights.
LEDs in and of themselves are not going to rid the world of wasted energy and light. Many of the current LED models are brighter than old-style sodium or mercury lamps, and many emit at the blue wavelength that does the most damage to melatonin production, which according to the American Medical Association has been linked in limited epidemiological studies to an increase in cancer, especially breast cancer.

The key will be to use less light overall by connecting the new LED streetlights to motion sensors to eliminate unneeded glare. Some cities, such as Phoenix and Flagstaff, Arizona, have ordinances to curb excess outdoor illumination, but most places are not, like Arizona, home to several important space observatories, which need dark skies. Ebrahimian, L.A.’s lighting director, says dimming the lights would be a big liability headache should people start blaming dark streets for their fender benders.
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