Patent ID: 7553568

Claim:
A method for operating an electrical current generation system comprising a high temperature fuel cell operating at a temperature of at least 250° C. including a cathode channel with air supply means delivering air to the cathode channel and an anode channel comprising an anode inlet and an anode outlet, whereby at least one hydrocarbon feedstock is subject to internal reforming in the anode channel to produce a hydrogen containing fuel gas, and a hydrogen recycle means configured to receive an anode exhaust gas comprising hydrogen from the anode outlet, and to enrich and recycle at least a portion of the hydrogen from the anode exhaust gas for supplying to the anode inlet, the method comprising: controlling the hydrogen recycle means and the air supply means to operate the high temperature fuel cell in a substantially thermally balanced regime at a normal design operating point, the system generating only enough high grade heat at a normal design operating point to be self-sustaining while substantially all waste heat of the system is rejected at a relatively low temperature; and controlling the hydrogen recycle means and the air supply means to shift the operating point of the system for peak power demands or for turndown to low delivered power generation.