Renewable energy sources have attracted wide attention because of being abundant in nature and nearly non pollutant. Wind power is one of the most promising clean energy sources it can easily be captured by wind generators with high power capacity. Solar power is another promising clean energy sources in global system and can be harnessed easily. Solar energy system might be compensate the wind intermittency generation resource due to lesser start up time, lower operating cost and good ramping capabilities. The generation scheduling for wind-solar energy with thermal unit system in deregulated environment, minimize the total thermal fuel cost emission and maximize the profit of generation companies, subject to many constraints. While performing the generation scheduling problem by Lagrangian relaxation based particle swarm optimization method the hourly load, wind velocity and solar radiation must be forecasted to prevent the errors. The generation scheduling formulations are involved the perspective of a generation company (GENCO). The deregulation environment is one which the generation, transmission and distribution does not depend on each other. To demonstrate the uncertainty in the proposed method the generating scheduling problem is performed in a simplified generation system.