The growing concern over environmental considerations and the increasing fuel cost call for operating the energy station in a more economical and environmentally friendly way. This paper develops a multi-objective model for the CHPED (combined heat and power economic dispatch) problem to conventional energy stations, where the competing fuel cost and environmental impact objectives are simultaneously optimized. To model the problem accurately, both non-linear fuel cost functions with valve-point loading effects and power transmission loss are explicitly considered in this model. A novel MLCA (multi-objective line-up competition algorithm) is proposed to handle the problem as a nonlinear constrained multi-objective optimization problem. Some diversity-preserving mechanisms are employed in the MLCA to produce well-distributed Pareto-optimal solutions. Moreover, a fuzzy decision-making process is applied to extract the best compromise nondominated solution from the Pareto-optimal set. The performance of the proposed method is validated by two typical systems. Comparison results have demonstrated the superiority of the proposed approach and confirmed its potential to solve the larger multi-objective CHPED problem. (C) 2013 Elsevier Ltd. All rights reserved.