An example system includes a power electronics system; a starter electrically connected to the power electronics system and configured to start a gas-turbine engine of an aircraft; and an energy storage system electrically connected to the power electronics system and configured to provide direct current (DC) electrical energy to the power electronics system, wherein the power electronics system is configured to deliver alternating current (AC) electrical energy to the starter to start the gas-turbine engine using the DC electrical energy from the energy storage system and AC electrical energy sourced from an AC electrical bus of the aircraft.