Patent ID: 6890671

Claim:
In a fuel cell power plant ( 10 ) having a fuel cell stack assembly (CSA) ( 12 ) and a fuel delivery system ( 16 ) for providing hydrogen-rich fuel ( 20 ) to the CSA ( 12 ), the fuel delivery system ( 16 ) including fuel blending means ( 28 , 30 , 37 , 39 ) adapted to be connected to at least a primary fuel ( 22 ) having a respective equivalent hydrogen content and a secondary fuel ( 24 ) having a respective equivalent hydrogen content for mixing at least the secondary fuel ( 24 ) with the primary fuel ( 22 ) and control means ( 18 ) for regulating the relative amounts of the primary fuel and the secondary fuel mixed to provide the hydrogen-rich fuel, the improvement in the method of controlling the mixing of the primary fuel ( 22 ) and the secondary fuel ( 24 ), comprising the step(s) of: selecting bio-gas as the primary fuel ( 22 ); and regulating ( 18 , 34 , 36 ) the relative amounts of the primary fuel ( 22 ) and the secondary fuel ( 24 ) mixed so as to provide at least a minimum level (LL) of hydrogen-rich fuel having an equivalent hydrogen content sufficient for normal operation of the CSA ( 12 ).