With the growing awareness of environmental implications and fossil fuel crisis, renewable energy harvesting (EH) technology has shown remarkable aptitude in green cellular networking and is expected to be pervasively utilized by telecom operators aiming to reduce carbon footprints. To take the full advantage of renewable EH technology, we proposed an energy sustainable paradigm to address energy self-reliance, eco-sustainability, and minimize the networks energy cost while meeting the quality of service requirements. This paper investigates the techno-economic feasibility of integrated renewable energy powered off-grid cellular base stations (BSs) taking into the account of stochastic behavior of RE generation and traffic intensity for remote areas in Bangladesh. Thereafter, a hybrid energy cooperation framework is formulated to optimally determine the quantities of RE exchanged among BSs via physically installed power cables. Under the proposed framework, each BS is equipped with on-site solar module/wind turbine coupled with an independent storage device, whereas collocated BSs are inter-connected through resistive lines. Extensive simulation is carried out for evaluating optimal system architecture, energy yield analysis, and cost assessment in the context of downlink long-term evolution cellular networks varying different system parameters. Results demonstrate the effectiveness of the proposed system performance pertaining to net present cost and energy savings. Finally, a comprehensive comparison with other schemes is provided for further validation.