Results of a literature survey done on optimization of generation thought that there is plenty of research study. With the depletion of conventional energy sources and increasing of load demand, there is a need of alternative energy sources, therefore non-conventional energy sources and distribution generation technologies continue to gain popularity. As nonconventional energy sources are intermittent, complete dependence on these sources also makes us to face difficulties such as availability of the electricity generated, weather conditions, cost of the equipment, reliability, power quality, voltage profile etc MG, which is a cluster of distributed generation sources, storages and loads that cooperate together in order to improve the power supply reliability, power quality and overall power system stability. It also integrates the advantages of power generation from alternative energy and non-conventional energy power generation systems connected to the grid. This paper presents different optimization techniques developed in recent days for minimization of cost, over emissions and curtailment of loads.