Various embodiments include an energy storage system for a hybrid energy system including a an energy storage device configured coupled to an inverter and controlled by a hybrid management system. The hybrid management system may be configured to use energy from the energy storage device to supplement power output of a power generation system to comply with a contract schedule of electric power output by the hybrid energy system. The hybrid management system may be configured to satisfy stable loads of an industrial application with the power generation system and to meet load swings of the industrial application with power output from the storage device. The hybrid management system may be configured to respond to an increasing desired load transient event by disclosing stored energy to follows a ramping profile that substantially matches a gas-turbine alone ramp rate of a gas turbine generator operating in a spinning reserve mode.