The energy consumption of mobile network infrastructures has been witnessed to rise significantly in recent years due to the massive growth of mobile traffic triggered by the increasing adoption of 5G networks and massive applications of the internet of things (IoT). The increase in network traffic not only demands network densification but also increases the operational expenditure (OPEX) of the mobile network operators as well as the environmental and sustainability concerns. To address such a challenge, green energy technology has received increasing attention. However, keeping the density of small cell base stations (SCBSs) and matching the dynamics of available energy variations to the user service request arrivals are non-trivial that need further investigation. This paper proposes to utilize the microgeneration of renewable energy (RE) infrastructure with traffic-aware load offloading integrated with advanced sleep mode (ASM) operation. The centralized renewable energy microgeneration approach is adopted to power the high density of SCBSs installed at a dispersed geographical location. The stochastic modeling-based traffic offloading can offload the macro base station (MBS) users to SCBSs depending on the traffic intensity. The advanced sleep mode stochastic model is presented to gradually manage the underutilized SCBSs into sleep modes based on the traffic load. The proposed scheme is developed to reduce the on-grid energy consumption whilst meeting the quality of service (QoS) requirement in terms of blocking probability and reactivation delay. The numerical results demonstrated that the proposed solution can achieve a significant amount of energy-saving depending upon the renewable energy availability and MBS traffic offloading with ASMs policies.