Renewable Energy Sources (RES) plants still have to operate at the maximum possible output and are therefore independent on electrical energy consumption. This fact has led to violation of the maximum overvoltage limit at the Point of Common Coupling (PCC) of power plants as well as violation of the maximum short-circuit power at many HV/MV substations. Therefore, the utilities are reluctant in penetration of additional RES plants to the system. Thus, coordination between distributed generators, energy storage systems and flexible loads is expected to add a great value to the grid operation and facilitate further RES penetration. The increased penetration of buildings' energy efficiency technologies at demand-side and their control possibilities over electrical energy consumption may also make valuable contributions to grid operations. Thus, the control system of the future grid should be compatible to building control strategies and automation systems. This paper presents an improved strategy for energy storage management and demandside management based on building energy efficiency technologies and its application to a microgrid-based smart grid topology.