Optimal Sizing of a Hybrid PV/Diesel/Battery System for Powering Off-Grid BTS Sites in Benin

The expansion of mobile networks generates high energy demand, especially in remote areas. In Benin, the use of diesel generators in these areas leads to pollution and energy losses on site in the event of fuel shortages. To solve these problems, the integration of renewable energy sources such as solar in mobile base stations is a promising solution. The objective of this study is to optimize the integration of intermittent renewable sources, powering the base transceiver stations (BTS). This leads to the reduction of CO2 gaze emissions and the reliability of power supply to mobile networks in remote areas. The work is based on optimizing a PV/Diesel/battery hybrid system in terms of energy production to permanently power the telecommunication systems. To achieve this goal, the NSGA-II genetic algorithm is employed, taking into account a non-linear load profile that perfectly reflects the energy demand of a BTS site. The results show that the optimal power system for BTS in Benin is composed of a 12 kW diesel generator and 50 solar panels with a peak power of 540 Wc and 30 modular 48V/150Aah batteries. This system would emit 3571.3282 kg/year CO2 with a Lost Power System Probability (LPSP) equal to 4%. The average monthly consumption of the existing site, which is the subject of this study and operates on a diesel generator, is 1500 liters per month, or 18,000 liters per month. This diesel consumption results in annual pollution of 53460 tons of CO2. With the integration of solar energy in this system, the theoretical results show a consumption of 1202 liters of diesel for a production of greenhouse gases of 3571 tonnes of CO2. We note a significant reduction of about 93% on the consumption of fuel oil and on the production of greenhouse gases.