In corona-based Wireless Sensor Networks (WSNs), nodes that are positioned in coronas near the sink drain their energy faster than others as they are burdened with relaying traffic come from distant coronas forming energy holes in the network. This situation shows significant effects on the network efficiency in terms of lifetime and energy consumption. The network may stop operation prematurely even though there is much energy left unused at the distant nodes. This paper present a mechanism that would avoid energy hole problem and prolong the lifetime of the network by balancing the energy depletion of all nodes in the coronas. In the proposed mechanism, the energy required in each corona for a balanced energy consumption is computed by determining the initial energy in each node with respect to its corona, and according to the corona load. The evaluation results showed that, by using the proposed mechanism, the energy consumption of coronas is balanced and the network lifetime is enhanced remarkably.