March 10, 2009 The cost and energy-efficiency of solid-state lighting are driving many new applications, and the recent installation of the first LED street lights in Osaka Prefecture in Japan, has already been found to provide an overall savings of 88% in electricity bills over the older high-pressure mercury lamps used elsewhere in the region. Each of the LED-based street lamps installed at a park on the Kizu River utilizes 36 cool white LEDs. The LED array generates 30 lux at a pole height of 4.5 meters, comparable to the brightness of mercury lamps, while using just 25 W of power per fixture.

In addition to energy savings, the LUXEON LEDs provided by Philips Lumileds offer a 60,000-hour lifetime (5 to 10 times longer than mercury vapor), mercury-free construction, and the ability to achieve uniform light distribution with minimal glare in street lamp applications because of the greater control over light direction made possible by the small form factor of the LED. Light can be precisely targeted through LED placement and optics optimization.