The integration of renewable Distributed Generations (DGs) has been a serious concern over reliable and satisfactory operation of the distribution system due to the intermittent nature of DGs. One of the solutions being proposed is the utilization of an Energy Storage System (ESS). However, without an appropriate energy management system, the integration of PV and ESS in a Plug-In Electric Bus Depot Charging (PEBDC) ecosystem can be harmful to the LV feeder. Therefore, this paper proposed a cost-efficient energy management system that is based on a double-sided auction mechanism that provides a platform to perform energy trading among the selling and buying agents in the PEBDC ecosystem. A simulation has been performed for the energy management of the PEBDC ecosystem considering the middle months of all four seasons Summer, Autumn, Winter, and Spring corresponding to January, April, July, and October, respectively. A mixed-integer linear programming (MILP) model has been formulated for Bus Depot Owner (BDO) profit maximization and analysed using IBM ILOG studio with CPLEX solver.