Systems and methods for controlling power flow to and from an energy storage system are provided. One energy storage system includes an energy storage device and a bidirectional inverter configured to control a flow of power into or out of the energy storage device via a plurality of phases. The energy storage system further includes a controller configured to control the bidirectional inverter based on a load condition on one or more phases. The controller is configured to control the bidirectional inverter to store power generated by a generator set in the energy storage device and transmit power from the energy storage device to a load driven by the generator set in response to detecting a load imbalance between the phases.