The solution of Economic Load Dispatch (ELD) problem is to allocate the total load demand to committed generating units with an objective to minimize the operating cost without violating the unit and system constraints. The growing power demand, atmospheric pollution and increased population makes it essential to invent a new power system with low pollution and transmission losses. The growing price and limited availability of fossil fuels makes installation of conventional power plants uneconomical. Installation of non-conventional power plants like roof top solar plants is essential to meet the increased load demand and environmental pollution standards. The output of roof top solar systems is intermittent because it depend on atmospheric conditions. To find a solution to economic load dispatch of distributed generation system (ELDDGS) with roof top solar plants is a difficult problem because of its intermittent and scattered nature. This paper will explain a solution to economic load dispatch of a distributed generation system using pattern search algorithm.