Choose Powered LED Street Lights or Solar LED Street Lights?

It has long been known that LED street lamps are more energy-efficient than high-pressure sodium lamps. However, some quantitative concepts may still be missing. It is now recognized that 100-watt LED street lights can replace 250-watt high-pressure sodium lamps, so it can be briefly considered that each LED street light can save 150 watts of electricity. However, if it is changed to solar power, even this 100W of electricity can be saved, that is to say, each street lamp can save 250 watts of electricity. According to estimates by relevant parties, the total number of existing street lamps in China is probably more than 100 million, and it is increasing at a rate of 20% every year. In 2008, 20 million street lamps were added. Assuming that these 100 million street lights can be converted into 60 million 250-watt street lights, and assuming that these 60 million street lights are all changed to solar LED street lights, then a total of 15 million kilowatts of power can be saved. Assuming that each street lamp operates 12 hours a day, 65.7 billion kWh of electricity will be saved in one year. The Three Gorges Hydropower Station in 2007 generated a total of 61.603 billion kWh of electricity. Therefore, the electricity saved by changing all the street lights in the country to solar street lights will exceed the annual power generation of a Three Gorges Hydropower Station. This is an extremely staggering number. Not only that, but solar energy is a clean, renewable power that not only saves electricity, but also cuts carbon dioxide emissions. Each 250-watt high-pressure sodium lamp will generate 1,290 kilograms of carbon dioxide within a year, so after all 60 million street lamps are converted to solar street lamps, it will be able to reduce 77.4 million tons of carbon dioxide. Therefore, after switching to solar energy, it not only saves electricity costs, but also saves the cost of carbon dioxide reduction. The abatement cost per ton of carbon dioxide is $345-404. A reduction of 77.4 million tons of carbon dioxide is equivalent to saving $31 billion in carbon dioxide reduction costs! 2. The power of AC power supply will be 15% lower than that of solar power supply. When using AC power supply, it is necessary to use a switching power supply to convert it to DC. The power of the general switching power supply is about 80%. Therefore, for a 100W LED street light, its communication input power needs about 120W (120W is selected in the comparison table below). When choosing solar power supply, you only need to choose DC/DC constant current source, and its power is as high as 95%. Therefore, after the calculation, the total power of the alternating current is about 15% lower. So the above figure should also add 15%. 3. Questions about communication power supply and power factor There is no compensation for the use of power factors in the switching power supply of lower level, and many of them will lead to a decrease in the overall power of the power grid in the future. 4. The biggest problem in using AC power supply is to reduce the life of the entire lamp. Because AC power must be rectified and filtered to become DC power, electrolytic capacitors must be used for filtering in all switching power supplies. As we all know, the lifespan of electrolytic capacitors is very low. The lifespan of general electrolytic capacitors is only 1000 hours, and the lifespan of electrolytic capacitors with longevity is only 10,000 hours. Moreover, the life span is reduced by half for every 10 degrees increase in the ambient temperature. In high-power LED street lamps, the temperature rise is very high, so the life of electrolytic capacitors is shorter. Generally, the life of LED street lights needs to be more than 50,000 hours. The life of the entire lamp will inevitably be affected by the short life of electrolytic capacitors. It can be considered that many low-quality LED street lights will fail quickly. In addition to accelerating their light decay because they have not dealt with the heat dissipation problem of the LED itself, the failure of the electrolytic capacitor in the communication power supply is also an important factor. There is no electrolytic capacitor in the solar power system. Therefore, the life of the constant current source can be guaranteed to match the life of the LED. 5. The overall cost of LED street lights powered by solar cells is much lower than that of a communicatively powered LED street light system. Although the initial installation cost of solar street lights is higher, the cost of laying cables and long-term electricity bills for communication power supply is much higher than that of solar systems. Let's do a detailed analysis below. (1) The cost of the LED lamp head and lamp pole of the two systems is roughly the same, the main difference is the solar panel. Generally, the power of solar panels is about 3 times that of LED lamps. If the LED is 100 watts, then you need to use a 300-watt solar panel. The current price of solar panels has dropped to 23 yuan / watt, 300 watts is 6900 yuan. In addition, the solar system also needs a battery, but its cost is equivalent to the cost of the switching power supply in the communication power supply. So the two can cancel. Therefore, the main difference in the cost of lamps and lanterns is the solar panel. (2) The biggest cost of communication and power supply LED street lights in the initial installation is the laying of cables. Most people think that the main thing is the cost of the cable itself, but in addition to the cable itself, its laying, auxiliary equipment (inspection wells, power distribution equipment), etc., are much more expensive than the cable itself. Now suppose that a 10-kilometer-long road is taken as an example, one lamp is placed every 30 meters and placed on the opposite side, a total of 666 LED street lamps are needed. If solar street lamps are used, the cost can be recovered within five years and 430,000 yuan can be saved. Five years later The annual electricity bill can save 1.22 million yuan.