Lighting engineering is a systematic engineering, which has covered many subjects such as the basic science research, engineering application technology, environmental lighting art, art history, economy, culture, management.
The application of LED light source is everywhere for people to see from the household appliances, transportation, display equipment to the engineering technology application. The landscape lighting and the site light show of the bird nest and water cube in 2008 Olympic Games all used LED lighting light source. In 2010, Shanghai Expo Site has used 1.03 billion single LEDs for lighting. The Expo Park has used 1700 sets of LED lighting lamps only. British pavilion “Seed Cathedral” used 60686 LED yakeli tentacles of the length 7. 5 meters; Germany pavilion adopts interactive device which is composed of 400000 LED magnetic metal balls; More than 70% night scape lighting adopts LED technology, which is the biggest LED application demonstration area at present.
Table 3 Domestic LED application distribution proportion
Function lighting mainly refers to the lighting, of which the lighting place has relative standard requirements, such as the requirements of the major parameters including the illumination, brightness ( Brightness Meter ), color rendering index, color temperature ( Color Temperature Meter ), glare and other parameters. This is kind lighting includes the lighting of sports, market, hospital, school, office work, roads and other places.
The roadway lighting of LED outdoor function lighting is currently in the experimental application stage. United states Department of Energy has tested the Minneapolis bridge street lamp in Sep., 2008, the results show that 20 sets of high pressure sodium lamps of 250 w can work for 4380 hours, with the yearly power consumption of 26465kWh, which saves 13% electric power. The return period cost in USA at least needs 13 years, because the electrovalence in US is half of that in China, human resource fees, and product fees are higher than China. Because the human resource fees, product fees in China are cheaper, the return period cost in China only needs 3-5 years.
In 2009, the Clinton foundation in LosAngeles demonstrated 150 thousand light LED lamps, set up the goal to replace 140 thousand street lamps in 5 years, and save 40% power.
In 2009, the test result by Shenzhen lighting environment management center shows that the average luminance ( Luminance Meter ) value of 27 sets of LED roadway lamps is slightly better than 100W high voltage sodium lamp. LED average value is close to 150W high voltage sodium lamp in12m×33m area, which is more than 17.6% of the 100W high voltage sodium lamp, the main application has already hold the condition. The minimum lumens depreciation of LED roadway is 5.9～8.0%, average value is 9-14.1%; The minimum lumens depreciation of high pressure sodium lamp is 8.7-16.1%. In recent two years, the LED roadway application is growing fast, which has brought many advantages and disadvantages. The advantage is that a number of good products have been experimentally applied, which has accumulated valuable experience for the future wide-range application. However, there are also some product performances and parameters that can not meet the requirement of the roadway lighting, which has brought much bad effects for the future popularization and application of LED roadway lamps.