Patent ID: 7923965

Claim:
A method for coupling an energy storage system to a variable alternating current energy supply system having a direct current (DC) bus side, said method comprising: providing an energy storage system including at least one Vanadium redox battery and at least one battery charge controller, wherein the at least one battery charge controller has a DC bus side and a battery side that is coupled to the at least one battery, the at least one battery charge controller including a DC/DC converter; and electrically coupling the DC bus side of the at least one battery charge controller to the DC bus side of the variable alternating current energy supply system such that the at least one battery is configured to supply a substantially consistent energy output to at least one of a utility grid and a critical load when an input to the variable alternating current energy supply system prevents the variable alternating current energy supply system from generating the substantially consistent energy output, wherein the at least one battery charge controller and the at least one battery are configured to absorb an entire output power of the variable alternating current energy supply system as needed for dynamic braking within the variable alternating current energy supply system.