In this paper, Modified Teaching Learning BasedOptimisation is used to solve the Economic Dispatch problems of the generating units considering valve point loadings effects. The formulation of the objective function is carried out in such a way that the losses are neglected and a clarified solution is obtained from the generating units. A recently developed optimisation is the Teaching Learning Based Optimisation which operates on two different phases-teacher phase and learner phase. A modification is done in the Teaching Learning Based Optimisation and is used in this paper as Modified Teaching Learning Based Optimisation. Here, in addition to the two phases, an mutation phase is also introduced. In contrast to the other Optimisation methods this proposed method does not require any algorithm specific parameters, it does not depend on any tuning parameters of algorithm and it enables global optimum solution and also avoids premature convergence to local optima of the objective function. The proposed method finds an optimum solution, such that minimum fuel cost solution can be obtained with extraordinary convergence rates and high consistency. The proposed method is tested on standard IEEE bus with 13 generating unit system, 40 generating unit system with valve point effects. The effectiveness of this method is demonstrated by comparing the results with other optimization techniques. Also, the result confirms that this proposed method has a great potential in determining the optimum solution.