Investigation and Feasibility Evaluation of Using Nanogrid Technology Integrated Into Road Lighting System

Currently, light-emitting diode (LED) technologies and solar power production are in popular use. This paper proposes the concept of improving conventional road lighting systems using LED technologies and solar energy applications, known as a “nanogrid road lighting system.” The power quality of a nanogrid road lighting system is analyzed in stand-alone and grid-connected operations using an experimental setup. In addition, the IEC 61000-3-2 (2018) Class C standard and power quality control regulations for grid connections are also discussed. The energy storage installed for individual and central systems are analyzed. Moreover, economic comparisons of three kinds of road lighting systems, namely grid-powered high-pressure sodium, LED solar stand-alone, and nanogrid systems, are compared in terms of their individual discounted payback period (DPP), net present value (NPV), and internal rate of return (IRR). The results show that in stand-alone mode, the system can effectively charge its batteries with the maximum power point tracking (MPPT) control and discharge power to supply the road lighting system. In the grid connection mode, the electrical energy produced from the solar power system can be supplied to the electrical grid at all ranges of solar irradiance levels with the MPPT control. However, a high total current harmonic distortion (THDi) flows into the electrical grid when solar irradiance levels are low. Solar road lighting systems installed in a central system have a low initial investment cost, resulting in better economic performance (in terms of DPP, IRR, and NPV). For this reason, using nanogrid road lighting systems shows satisfactory feasibility in terms of power quality and economic performance.