Smart Grid (SG) is envisioned to become one of the leading technologies of the modern era by imparting information, and communication technology to the traditional electric grid. The power, and energy sector faces challenges to meet the continuously increasing demand of power. However, this is constrained by the limited fuel resources, as well as the threats faced by the global climate. To maximize the utility of SG in the present scenario, it can be integrated with Distributed Energy Resources (DERs). DERs, which include Renewable Energy (RE) sources, and Electric Vehicles (EVs), provide an optimal solution to the power, and energy problems faced by the world today. This paper proposes a green energy system, consisting of DERs, a Central Energy Management System (CEMS), and a Seasonal Thermal Energy Storage (STES) system. The STES system employs waste heat, and solar thermal energy to provide a clean solution to heating, and cooling demands of the community. The CEMS monitors, and regulates the flow of electrical, and thermal energy in the proposed system. The CEMS proposed in this paper is based on fuzzy rough set theory. The prime objective of this scheme is to implement a real-time green energy management system in SG environment to make a balance between demand, and supply.