Abstarct: In this thesis, a stochastic model is proposed for modeling real-time energy management of virtual power plant (VPP). This VPP consists of distributed generation resources (e.g., solar power station and thermal unit), energy storage units and price-responsive demands, which are connected through a small size electric energy system. Additionally, the VPP can exchange energy with main grid. The proposed model maintains system security in an appropriate level by scheduling energy and spinning reserve capacity. Uncertainties in solar power production and energy price are presented through single-point forecast. Uncertainty in availability of network equipment is modeled by scenarios. The stochastic model is implemented in a small size electric energy system with different degrees of system vulnerability. Results show the good performance of the model in the system contingencies.