Growing concern about global warming and energy consumption, utilizing green energy to power cellular base stations (BSs) is an attractive solution to reduce operational expenditure and global carbon emissions. With the advancement of renewable energy (RE) generation technology, cellular operators are increasingly deployed solar energy system that could be made financially viable in cellular industry with the added merits of minimum maintenance. The random and dynamic nature of green energy generation could lead deterioration of the quality of service (QoS) and impose severe challenges to design reliable cellular systems. To increase the self-reliance, the integration of diesel generator (DG) with the solar energy harvester (EH) has drawn intensive attention for the envisaged off-grid BSs. In this paper, we extensively explore the energy sustainability, cost-effectiveness, energy efficiency and reliability of the proposed hybrid power sources for cellular communications taking advantages of photovoltaic (PV) technology. The prime intention of adopting solar energy in telecom sectors is to minimize the diesel consumption as well as meet the challenges of climate changes. Simulation results demonstrate the validity of the proposed technique and sustainability can be ensured with better planning by providing cleaner energy.