Stand alone solar powering for fiber-in-the-loop systems

A key concern in fiber-in-the-loop systems is reliable powering of end-loop optical network units (ONUs). The technical and economical feasibility of using stand alone solar-photovoltaic (SAS) systems for powering these units is examined. Arrays of photovoltaic cells located at or near the ONU are connected to a battery and the ONU electronics. During normal sunlight conditions, electricity from the panels powers the electronics and charges the batteries. During periods of poor or no sunlight, the energy stored in the batteries powers the load. The use of solar powering for general telecommunications applications and the factors which make the technology attractive for this specific application are discussed. A demonstration SAS system for study of technological issues in solar powering ONUs is described, and its economics are examined. It is concluded that while SAS is not a universal solution for powering ONUs, it may be cost-effective in areas with high insolation and loops longer than 5000 ft