Development of solar street lamp with energy management algorithm for ensuring lighting throughout a complete night in all climatic conditions

The paper proposes design of a solar energy LED street lamp with energy management algorithm for estimation of solar energy stored in the battery, determination of night hours and controlling the intensity of the street lamp for effective utilization of stored energy. This ensures working of the street lamp for a complete night without switching OFF in between the night, especially in rainy or cloudy seasons when less energy is stored in the battery. The total input charge to the battery is counted by integrating the charging current for a complete day time and the night time is counted by sensing the absence time of solar panel output in the previous night. Based on the above measured parameters, the intensity of the LED lamp is set in the night hours in a specified intensity pattern according to the traffic hours so that light from street lamp is available throughout the night without getting battery discharged fully in the midnight and causing a blackout. The system is developed using a microcontroller and practically implemented for realization.