Design and Optimization of a Renewable-Energy Fully-Hybrid Power Supply System in Mobile Radio Access Networks

The worldwide continuous growth of mobile subscriptions and broadband data demand is leading to an increase in hardware complexity of the base stations making up the mobile Radio Access Networks (RAN). This technological trend will inevitably result in increasing RAN energy consumption. In addition, the electrical grid accessibility issues encountered in developing countries bring a serious concern for telecom carriers who are constantly looking to reduce their networks operating expenditure (OPEX). Regular periodic maintenance and fuel consumption of on-site Diesel Generators are one of the main contributors to RAN OPEX. In this paper, an exhaustive yet compact model of a radio base station’s running cost is first introduced to provide telecom carriers a mathematical tool to estimate accurately their overall expenditure. Secondly, a generic Design & Optimization MATLAB tool is developed to minimize this cost by introducing, to the existing grid-generator solutions, renewable-energy (RE) sources to form a fully-hybrid power supply system (HPSS). CO2 emission is also integrated into the previous model to form a compound objective function for optimization. Finally, to achieve an optimal power supply system with both minimum annual OPEX and CO2 emissions, the core algorithm of this work computes the target duty-partition configuration among RE sources, on-site Diesel generators and utility grid. The software outputs in addition the required system design parameters for the RE sources to be installed on site.