The static var compensator (SVC) is a cost-effective device in flexible AC transmission system (FACTS) family. We introduce an improved artificial hummingbird algorithm (IAHA) for optimal allocation of SVCs in distribution networks to maximize energy efficiency. Three loading levels (low, medium, and high) per day are investigated. The proposed IAHA is evaluated on the IEEE 33-bus distribution network (DN) and 69-bus DN. The proposed IAHA demonstrates notable improvements in cost savings and voltage profile compared with the conventional artificial hummingbird algorithm (AHA). In addition, it enhances energy savings across various loading conditions and outperforms the conventional AHA in both best and average performance metrics. Although raising the compensation limit initially increases cost savings, the benefits decrease beyond a threshold, highlighting the importance of balancing the compensation levels for maximum efficiency.