Patent ID: 8071246

Claim:
A method of operating a reversible fuel cell electrochemical system capable of a fuel cell mode and an electrolysis mode, comprising: operating a fuel cell at a first operating efficiency and a first throughput, the first operating efficiency being about equal to an optimum efficiency and the first throughput being below an optimum throughput; receiving at least one of a cost of electricity and a cost of fuel; and adjusting at least one of an operating efficiency and throughput of the fuel cell based on the at least one of the received cost of electricity and the received cost of fuel to operate the fuel cell at a second operating efficiency or a second throughput different from the first operating efficiency and the first throughput; wherein the step of adjusting comprises adjusting the operating efficiency below an optimum efficiency and adjusting the throughput of the fuel cell to be about equal to an optimum throughput when the fuel cell electrochemical system is operating in the fuel cell mode and when the cost of electricity is higher than a predetermined cost or the cost of fuel is lower than a predetermined cost; and wherein the step of adjusting comprises adjusting the operating efficiency below an optimum efficiency and adjusting the throughput of the fuel cell to be about equal to an optimum throughput when the fuel cell electrochemical system is operating in the electrolysis mode and when the cost of electricity is lower than a predetermined cost or the cost of fuel is higher than a predetermined cost.