The paper presents a new method based on a hybrid algorithm consisting of imperialist competitive algorithm (ICA) and sequential quadratic programming (SQP) technique to solve the power system economic load dispatch (ELD) problem. ICA could be taken into account as a powerful technique. Nevertheless, it may be trapped in local optima especially when numbers of imperialists increase. To alleviate this drawback, SQP is used to fine-tune the results of ICA to increase confidence in the solution. Renewable sources and wind energy especially have recently been getting more interest because of various environmental and economical considerations. So, wind power is included in the problem formulation. The incomplete gamma function (IGF) is used to characterize the impact of wind power. The hybrid imperialist competitive algorithm (ICA) and sequential quadratic programming (SQP) technique (HIC-SQP) is applied to solve economic load dispatch with incorporating stochastic wind power. To evaluate its effectiveness, the proposed method is tested on various power systems with 6, 13, 15, and 40 power plants with and without wind power. Simulation results of proposed method are compared with state-of-the-art heuristic optimization methods. It can be clearly seen that the proposed method improves the solution of ELD problem. (C) 2014 Elsevier Ltd. All rights reserved.