Conventional planning and optimization of cellular networks for supporting the peak-time user demand leads to substantial wastage of electrical energy. Therefore, we propose an energy-aware dynamic network provisioning framework for realizing green mobile cellular systems by reducing energy consumption in access networks. Proposed mechanism allows base stations (BSs) to offload their entire traffic to the neighbors and thus allows some BSs to switch into sleep mode for saving energy. Four different traffic offloading schemes for redistributing users among the neighboring BSs are proposed and investigated. Flexible resource allocation is integrated in the system for maintaining quality of service (QoS) throughout the network. Furthermore, for avoiding the high complexity of the formulated generalized energy optimization problem, a heuristically guided algorithmic framework is developed. System performance is evaluated using extensive simulations demonstrating a substantial energy savings. Impact of the proposed network provisioning framework on the bandwidth utilization is also analyzed.