Technical & economical evaluation of solar powered LED street lights: An overlook contributor to load-shedding

The traditional Street Lighting System (SLS) in Pakistan is based on mercury and sodium-vapor lamps. The individual lamp in SLS consumes 60 W to 600 W from the utility system. This increased power consumption ultimately affects the commercial and residential consumers thereby causing load-shedding during the peak hours. To reduce the power consumption and to shed some load from utility network, solar powered Light Emitting Diode (LED) Street lighting system has been suggested by the ministry of planning and development of Pakistan across the country. The LEDs with an equal luminance of 72 lm/w comparing to 250 W sodium-vapor or mercury lamp consume 100 W. Since the capital cost of installing solar powered LED lighting system is higher than traditional lighting system. But on the long term planning scale, the results are very much promising, resulting in 60% saving of energy. To evaluate the technical and economical feasibility of solar powered street lighting project, this research investigates the performance and installation cost of LEDs based SLS in the urban region of Sindh, Pakistan, with two lanes having pole distance of 30 m. This study shows that the total cost of installing the solar powered LED SLS is 21.25 million PKR and 13.98 million PKR for utility powered LED SLS as compared to 5.48 million PKR for traditional SLS, except electricity charges. On average, the deployed traditional SLS consumes 547,500 kWh/yr. The payback time for suggested solar powered LED lighting system is 5.384 years. The reliability and efficacy of results were assured through HOMER software.