An energy storage system stores potential energy and providing a regulated output of electrical energy for powering an electrical load. The system includes an array of storage capacitors including a plurality of storage capacitors coupled in series. A balance control device balances the voltage on each of the storage capacitors in the array. An input control device manages the input for charging the storage capacitor array. An output power supply has an input coupled to the storage capacitor array and provides regulated power to an electrical load. A power monitor device electrically decouples the storage capacitor array from the electrical load when the total voltage of the storage capacitor array falls below a preset minimum level.