Design and Optimization of Solar PV/Diesel Generator Hybrid Power System for Remote Telecommunication Base Transceiver Stations in Nigeria

Abstract

Due to the creeping growth of mobile telecommunication subscribers in cities and a compulsory demand for a telecommunication network in remote locations, Nigerian mobile network operators (MNOs) have begun to look for potential customers in previously unreached locations. Unfortunately, they are confronted with the prohibitive cost of powering remote off-grid macro base transceiver stations (BTS) with diesel generators and its associated environmental impacts. Nigeria is a country with huge potential for solar energy due to its closeness to the equator, but this resource has remained untapped for telecommunication sites despite its important benefits. Therefore, this study investigates the possibility of using a hybridized solar photovoltaic (PV)/diesel generator (DG) system (with battery) as a reliable, economical and environmentally suitable power source for off-grid micro BTS in the Nigerian rural areas. In this thesis, HOMER (Hybrid Optimization Model for Electric Renewable) simulation tool was used to model an off-grid solar PV/DG/battery hybrid power system for a micro telecommunication site load. Five possible optimal system configurations (OSC) were presented from the simulation of the hybrid power system (HPS) amongst which hybridized solar PV/DG/battery was ranked as the most viable in meeting the objectives of this study. The focal point of this thesis was to investigate the effect of varying climatic conditions (annual average solar radiations) on the OSC. To achieve this, six different annual average solar radiation values (4.33, 4.50, 4.76, 5.51, 5.81 and 5.97 kWh/m2/day), which represent selected rural locations for the BTS across the geopolitical zones in Nigeria, are used as sensitivity variables with a hypothetic site which receives 5.68 kWh/m2/day. Furthermore, three key aspects of the possible OSC for the regions were examined, namely; (i) energy output (renewable energy fraction), (ii) economic implication (net present cost), and (iii) environmental impact (carbon emissions). The results of this study showed the possibility of having at least 87% of Nigeria’s remote BTS load demand from solar PV alone, which is a clean energy source. This helped to reduce the use of a diesel generator and consequently fuel consumption. It also provided important cost benefit to MNOs in terms of 47.3% drop in the net present cost when compared with the conventional diesel/battery system. Although, the aim of this study is not to show the most viable location for the proposed hybrid power solution, however, the results obtained provides a valuable insight into the techno-economic implications of deploying solar PV/DG/battery HPS across the Nigerian remote off-grid sites.