Sustainability has become an imperative requirement on many infrastructures and systems of our society with the impending energy crisis and environment deterioration.Power grids are being transformed into smart grid with advanced sensors, information and communication technologies.In smart grid, the energy flow will become two-way between the grid and consumers with renewable energy generations, which will be monitored and controlled by sensors, smart meters, digital controls and analytical tools. Smart Grid usually introduces [http://en.wikipedia.org/wiki/Demand_response Demand Response (DR)] and [http://en.wikipedia.org/wiki/Distributed_generation Distributed Generation (DG)] to improve energy consumption and generation efficiency.