Grid-connected solar-powered cellular base-stations in Kuwait

Abstract

Recently, the number of mobile subscribers, wireless services and applications have witnessed tremendous growth in the fourth and fifth generations (4G and 5G) cellular networks. In turn, the number of base-stations (BSs) has increased rapidly for wider ubiquitous networking; however, powering BSs has become a major issue for wireless service providers. Most BSs are either grid-connected, which are powered via fossil fuels-dependent power plants, or are off-grid, and operated via diesel generators. Hence, BSs are responsible for carbon dioxide (CO2) emissions. Intuitively, utilizing photovoltaic (PV) solar energy has posed itself as an alternative “green” renewable energy source. This paper studies utilizing PV solar power to energize on-grid (G) cellular BSs in Kuwait, and selling excess PV energy back to the grid to minimize the total cost over the BS operational lifetime. To this end, an on-grid electrical system is designed to power a 4G/5G cellular BS at an urban cell-site. Various electric system configurations are modeled, simulated, and optimized via the HOMER software, while incorporating PV panels, a diesel generator (DG), and/or a battery bank (BB). Comparisons are conducted in terms of net present cost (NPC), CO2 emissions, energy sold, and required system area. The simulation results revealed that the on-grid system configurations yield significantly lower NPC than their off-grid counterpart systems and the PV-G system configuration is the most economical. However, it cannot guarantee system autonomy in power outage scenarios, as it does not contain energy storage devices. Alternatively, the PV-BB-G system configuration is shown to be more reliable than the PV-G configuration, but at the expense of marginally higher NPC. Also, utilizing a dual-axis tracker has been shown to further reduce the NPC and CO2 emissions. In general, increasing the sell-back price effectively reduces the NPC and CO2 emissions, and increases energy sold, however, entails greater system area.