Uncertainty can be defined as the probability of difference between the forecasted value and the real
value. As this probability is small, the operation cost of the power system will be less. This purpose necessitates modeling of system random variables (such as the output power of renewable resources and the
load demand) with appropriate and practicable methods. In this paper, an adequate procedure is
proposed in order to do an optimal energy management on a typical micro-grid with regard to the relevant uncertainties. The point estimate method is applied for modeling the wind power and solar power
uncertainties, and robust optimization technique is utilized to model load demand uncertainty. Finally, a
comparison is done between deterministic and probabilistic management in different scenarios and their
results are analyzed and evaluated.