A method based on the novel optimization algorithm of Invasive Weed colonization Optimization (IWO) is used to study electricity market dynamics. Dynamics of such a multi agent system is analyzed using aspects both from Game theory and IWO. The method is integrated with a power system simulator to consider all the constraints of a realistic power system to make sure that the results are reliable. The IWO has also been introduced briefly and it is discussed why this method is supposed to be appropriate in such problems. Several simulation studies are presented to show how the method works. These outputs are compared with what exist in the literature. It is shown that making use of search based optimization algorithms such as IWO is necessary for consideration of all the constraints and details.