Lighting consumption accounts for about 20 percent of the total power consumption, and greatly reducing lighting power is an important way to save energy. LED is attracting the world's attention with its advantages of solid use. The United States, Japan and other countries and Taiwan area of LED lighting efficiency is forecasted, 55% of incandescent lamp, fluorescent lamp is LED us to replace, can save $35 billion a year electricity, can reduce 755 million tons of carbon dioxide emissions a year. Japan's 100 per cent incandescents are replaced by leds, which can reduce power generation by 1-2 plants and save more than 1 billion litres of oil a year. In Taiwan, 25% of incandescent bulbs and 100% fluorescent bulbs are replaced by leds, saving 11 billion kilowatt-hours of electricity a year. LED lights will also create a $50 billion industry market. In recent years, famous lighting companies such as philips, osram and GE have launched LED semiconductor lighting plans, set up state-level key laboratories and invested heavily in development research. Occupy the forefront of the field of LED lighting. -2-1. As the world energy crisis intensifies, countries are seeking solutions to the energy crisis. One path is the search for new and renewable sources of energy; The other is to seek new energy-saving technologies, reduce energy consumption and improve energy efficiency. Lighting source in the past one hundred years, has experienced three important stages: incandescent lamp, fluorescent lamp, high intensity discharge lamp (HID), now in the lighting industry has a broad development prospects of the LED light source is known as the fourth generation light source. LED as a light source of emerging, with long service life, high luminous efficiency, low power consumption, start time is short, high color rendering index, low working temperature, firm structure, is not afraid of vibration, good directivity, low work voltage, no ultraviolet radiation, and other significant characteristics of light weight, is the world's most development potential of a new generation of light source. Moreover, LED light source can realize mercury-free production, which is also of great significance to environmental protection. Using semiconductor LED as a solid-state lighting, it will gradually replace the traditional floodlight and enter into various applications. At present, lighting consumption accounts for about 20% of the total power consumption, greatly reducing lighting power is an important way to save energy. LED is attracting the world's attention with its advantages of solid use. The United States, Japan and other countries and Taiwan area of LED lighting efficiency is forecasted, 55% of incandescent lamp, fluorescent lamp is LED us to replace, can save $35 billion a year electricity, can reduce 755 million tons of carbon dioxide emissions a year. Japan's 100 per cent incandescents are replaced by leds, which can reduce power generation by 1-2 plants and save more than 1 billion litres of oil a year. In Taiwan, 25% of incandescent bulbs and 100% fluorescent bulbs are replaced by leds, saving 11 billion kilowatt-hours of electricity a year. LED lights will also create a $50 billion industry market. In recent years, famous lighting companies such as philips, osram and GE have launched LED semiconductor lighting plans, set up state-level key laboratories and invested heavily in development research. Occupy the forefront of the field of LED lighting. Each year, according to the our country has used for lighting power close to 250 billion degrees, which if adopted a third LED lighting, could save 80 billion KWH per year, basically the equivalent of a power generating capacity of the three gorges power station, to alleviate the increasingly serious energy crisis in our country, power shortages will play a great positive role. To this end, China has set up the national semiconductor lighting committee, introduced the national semiconductor lighting project plan, established the LED industrialization base, and promoted the healthy development of China's LED industry. According to the requirements of city road lighting design standards, motor vehicle traffic road lighting should be with average brightness (or road) the average illuminance on the pavement, road surface brightness uniformity and longitudinal uniformity or road illumination uniformity, glare restrictions, environment than and induced as evaluation indexes. Pedestrian roads and residential lighting should be in the road, the average illuminance on the pavement of minimum intensity of illumination and vertical illumination as evaluation refers to using high power LED lights used for road lighting, compared with the traditional high pressure sodium lamp has incomparable advantages: 1. The light emitting mechanism is different, because the LED is a semiconductor device, the effective life of up to 50000 hours (i.e. after 50000 hours, light failure is less than 30%), far higher than that of sodium lamp and metal halide lamp (their lifespan in about 12000-12000 hours). 2. Because the LED is a semiconductor material, it has no filament and other attached materials, so its shock resistance is good. 3. The display color index of LED light illuminator can reach above 80, which is close to natural light, and the human eye is more likely to discern things in this situation, which is conducive to driving safety. The high - pressure sodium lamp has an index of 20-30. 4. Traditional gas discharge lamps such as high pressure sodium lamps have a preheating process when they are started, which wastes energy and is not conducive to intelligent control. LED street lamp because there is essential difference in the light source, there is no "start-up time" problem, with electricity can work immediately, it can be very convenient to realize intelligent energy-saving control. 5. As a result of the traditional street lamps light source is used to light the mechanism of mercury vapor, therefore, the processing of waste light source is the problem urgently to be solved in the world today, at the same time, the traditional light emitting mechanism determines its harmful ultraviolet radiation. LED light source is solid state lighting, no harmful substances such as mercury, nor emit ultraviolet light, therefore, is environmental protection light source. 6. In optical system, the traditional street lamp light source is omnidirectional light, half of the light is reflected by the reflector, the reflector is to absorb part of the light, so the light loss is larger. Because leds are unidirectional, light is more efficient than traditional streetlamps. 7. The traditional street lamp light distribution curve is determined by the reflector, so has certain limitations, and LED light source is a kind of distributed source, through the design of the electric light source, make the light source of lamps and lanterns is the ideal bat wing shape, through reasonable control the distribution of the light, make the road flare rectangular, in the effective range, higher intensity of illumination evenness. 8. More perfect automatic control (optional) : can set different brightness according to the needs of different time periods, and improve the efficiency of energy saving. For example, it is 200W at 7 o 'clock in the evening. When people are young at midnight, the brightness is automatically adjusted to 100W, which can also save 60W. Now td lighting design, the lamp is apart from the general is 3 times of light is high, and high light in general is equal to the right of the road, according to the geometric triangle lighting lamps and lanterns of light distribution can be calculated Angle shall be C0/180 direction about 140 degrees, C90/270 direction about 80 degrees. According to the current traffic light design standard, the distance between street lamps is usually 3 times higher than that of the lamp, because the relationship between the light distribution curve of the conventional light source causes some dark areas which cannot be illuminated by the light source. This not only causes the waste of energy, but also brings great inconvenience to the night driving, resulting in safety hazards. The LED application with special light shape is applied to the street lamp, which can offset the luminance Angle of the lamp, and improve the lighting efficiency of the roadside. According to the aspect ratio of rectangle can produce the aspect ratio of 2:1 flare, so will not appear between adjacent light shadow, can form on the road a bright illumination uniformity of light, and therefore more in line with the current traffic road lighting design, do not need to increase the light pole height can meet the illuminate of enough wide range, but also improve the efficiency of the lighting lamps and lanterns, reduces the road lighting power density, so as to truly achieve energy saving and environmental protection. Calculated on a city 50000 streetlights, transform traditional street lamps with LED lights, 10 years 300 million yuan can save electricity, can save $30 million per year on average electricity, if using LED street lamp at construction stage, save the investment cost is more significant. At present, lighting consumes about 20 percent of the electricity used in the whole society. If LED instead of traditional light source, it can reduce the lighting power by more than 50%, and play a huge role in the target of energy saving and consumption reduction of 4%. According to the standard coal consumption of 396 g /KWh of thermal power generation in our country, the annual power saving of each LED street lamp is 5694KWh, which can save 2254.8 kg of electric coal. According to the calculation of 175.4g of carbon dioxide and 8g of sulfur dioxide emitted per KWh, each LED street lamp can reduce carbon dioxide emissions by 998.7 kg in 10 years, and reduce sulfur dioxide emissions by 45.6kg.