Solar Street Lights: Factors to Consider in the Design of Solar Photovoltaic Power Generation Systems

The solar AC power generation system of solar street lights is composed of solar panels, charge controllers, inverters and batteries; the solar DC power generation system does not include inverters. In order to enable the solar power generation system to provide sufficient power for the load, it is necessary to reasonably select each component according to the power of the electrical appliance. The design of the solar power generation system needs to consider the following factors: Q1. Where is the solar power generation system used? How is the solar radiation in the area? Q2. What is the load power of the system? Q3. What is the output voltage of the system, DC or AC? Q4. How many hours does the system need to work every day? Q5. In case of rainy weather without sunlight, how many days does the system need to supply power continuously? The following takes (load) 100W output power and uses 6 hours a day as an example to introduce the calculation method: 1. First, calculate the watt-hour consumption per day (including the loss of the inverter): If the solar street light inverter has The conversion efficiency is 90%, then when the output power is 100W, the actual output power should be 100W/90%u003d111W; if it is used for 6 hours a day, the power consumption is 111W*6 hoursu003d666Wh, which is 0.666 degrees Electricity. 2. Calculate the solar panel: Calculated according to the daily effective sunshine time of 5 hours, and considering the charging efficiency and the loss during the charging process, the output power of the solar panel should be 666Wh÷5h÷70%u003d190W. 70% of which is the actual power used by the solar panel during the charging process. 3. The daily power generation of 180 watt modules is 180×0.7×5u003d567WHu003d0.63 degrees 1MW daily power generationu003d1000000×0.7×5u003d3500,000u003d3500 degrees Example 2: A 10w lamp is installed, lighting 6 hours a day, 3 consecutive In rainy days, how to calculate solar panel wp? and 12V battery ah? Daily power consumption: 10WX6Hu003d60WH, Calculate solar panel: Assume the average peak sunshine hours of your installation site is 4 hours. Then: 60WH/4 hours, u003d15WP solar panel. Then calculate the charge and discharge loss, and the daily supplement to the solar panel: 15WP/0.6u003d25WP, that is, a 25W solar panel is enough. Then calculate the battery. 60WH/12Vu003d5AH. The power consumption of 12V5AH is used every day. For three days, it is 12V15AH. The battery configuration needs to be designed so that the daily power consumption does not exceed 20%, or the power consumption does not exceed 50% during continuous rainy days. In order to achieve the longest battery life requirements.

In this way, we conclude that the battery of this solar street light system is 26AH-30AH enough. Example 3: How many watts of solar panel does it take to charge a 12V45A battery in 6 hours? The 12V45A battery is 648Wh (?) If it needs to be fully charged in 6 hours, the solar panel is theoretically only 108W, but in reality, the 108W panel is less than 12V45 due to factors such as sunlight intensity, temperature, photovoltaic controller efficiency, overall efficiency and other factors. The overall efficiency of the battery is calculated by 0.8. You need to choose a 135-watt solar cell module. By the way, the best charging current for a lead-acid battery is 1/10 of the battery capacity current, which is 4.5A. Excessive charging current will speed up the battery plate. Sulfurization affects battery life. The simplest calculation method: Battery: 12V×45Au003d540WH Solar panel poweru003d540/6/0.8(loss)u003d112.5W a couple of hours? An ordinary 12v4AH battery, how many hours does it take to charge it with those two solar panels? The working voltage of the 1.20W solar panel is generally 17.2V and the current is 1.15A. If the quality of the board is good, the measured current is generally 1.1A (I have tested it). 2. Assuming that the 6 hours of light you are talking about is from noon to the afternoon, then it can be counted as 4 hours of full power generation, that is to say, 2 20W boards can generate 2*1.1*4u003d8.8A per day. 3. This is 17AH The battery can be fully charged in 2 days; 4AH only takes 2 hours. Or the total w number of solar panels is 20+5u003d25W, the total number of batteries w is 12v*17Au003d204w, and the full time is 204/25u003d8 hours and 4A batteries: 4A*12u003d48w 48w/25wu003d1.92 hours