Abstract:
Due to increasing demand of energy, utilization of renewable energy sources are getting larger attention from researchers all over the world. Solar Photovoltaic (PV) is a renewable source of great potential due to its abundancy, ease of accessibility, convertibility to the electricity and environmental friendliness. Solar PV system along with light emitting diode (LED) have become extremely popular nowadays for street lighting purposes. LED lamps are used due to their higher lumens yield with less wattage consumption. So, this paper presents an energy efficient sun-tracking solar PV powered auto LEDbrightness controlled street light model based on traffic-density monitoring system with wireless control via nRF and GPRS technologies. The microcontroller based dual-axis sun-tracking system along with four light dependent resistor (LDR) sensors are used to keep the solar panels aligned with the sun in order to maximize the amount of harnessed solar power. The street lights are automatically switched on at the dusk and then switched off at the dawn using LDR sensors. Depending on trafficdensity in the street, which is measured by ultrasonic and motion sensor based traffic-monitoring system and the yield of solar PV, the lumen-intensity of LED based street light is adjusted by pulse width modulation (PWM) to save more energy. We have also configured the system with nRF and GPRS technologies, which allow us to manually operate and monitor the street-lights wirelessly from remote places. Thus, the proposed system facilitates remote monitoring and generates 20% more energy than stationary solar panels while reduces LED power consumption by 15.7% per day