Using renewable resources like solar energy to power the base stations (BSs) has emerged as a promising solution for greening cellular networks. One of the key challenges in operating a network of such BSs is to intelligently manage the green energy available to the BSs while ensuring reliable quality of service (QoS). This letter presents a methodology for maximizing the QoS, in terms of the network latency, given the constraints on the energy availability at the solar-powered BSs. In contrast to existing approaches based on user association reconfiguration, our methodology uses a combination of intelligent energy allocation and BS downlink power control. Using a real BS deployment scenario from U.K., we show the efficacy of our algorithm and demonstrate its superior performance compared to existing benchmarks.