Abstract: A system for providing a rapid threshold amount of power to a customer load during transfer between a primary power supply and a secondary power supply is disclosed. The system is electrically connected between a customer metering system and the customer load. The system includes a secondary power supply not in electrical connectivity with the primary power supply. The secondary power supply includes a secondary power supply source for generating electrical power, a switching module, and an energy storage system in electrical communication with the secondary power supply source and the switching module. The energy storage system includes a high discharge battery and is configured to rapidly discharge power to the customer load when the switching module switches between the primary power supply and the secondary power supply. The switching module includes at least one set of contacts in communication with at least one inverter of the secondary power supply.