An off-grid base station PV hybrid design that minimizes fuel consumption.

Abstract

With the continuous expansion of the communication network and the necessity to provide coverage to people located in areas with no grid connection or bad grid connections due to frequent outages of low voltage. There is a need to get an optimal power supply source that can enable the establishment of base stations in such areas to cater for coverage expansion. Diesel generators which are the widely used source of energy in off-grid areas face the the challenge of increasing carbon dioxide emissions which is harmful to the environment as it contributes to greenhouse gas emissions and therefore increasing the carbon footprint. The diesel generator has poor performance as most of the energy about 30% is lost as heat and it faces unreliability issues such as failure to start up especially during cold periods. Telecom operators have tried to alleviate this problem by use of a PV-hybrid system that takes advantage of the diesel generator as well as the benefits of green energy solutions. Thus, such systems can fully power the base stations and are not extremely big to not fit on the base station site. However, though such systems have been implemented in many of the base stations owned by American Tower Company (ATC), there is continued fuel consumption by the base station with a considerable budget of those Tower company’s expense being on fuel. This is due to the poor PV-Hybrid designs in use by ATC. ATC uses the same PV-hybrid design irrespective of the peak sunshine hour, and base station load. All the designs have a diesel generator rating of 20kVA, 14 PV panels of 320W each, the rectifier of 18kW, three Maximum Power Point Tracking (MPPT) each 63A. For to achieve benefits from the PV hybrid system, there is a need to design the system basing on the base station load and the area's sunlight intensity. This would imply that the designs would vary for the various locations. The project investigated the outcome of adopting a design that takes into consideration the base station load and the area's sunlight intensity versus the existing PV Hybrid system that does not account for the variations in base station load and sunlight intensity. It also outlines the savings that would be obtained when the design PV Hybrid system is adopted. This project shows that to achieve the benefits from a PV-hybrid system for a base station, there is a need to consider the base station load as well as the sunlight intensity of the in the question to come up with a design that can fully supply the load while maximizing the sunlight intensity and cater for load growth.