NOVELTY - Method comprises: (a) producing a bio-fuel from a first source, thus a residual source waste stock remains after the production of the bio-fuel; (b) providing an animal feedlot including animal manure waste stock; (c) providing at least one gas turbine configured to produce exhaust gases; (d) contacting the exhaust gases produced by the gas turbine with animal manure waste stock to produce a fertilizer; and (e) contacting the exhaust gases produced by the gas turbine with the residual source waste stock remaining after the production of the biofuel to produce animal feedstock.    USE - The method is useful to produce a biofuel (ethanol or bio-diesel) from a source such as a grain (corn) or algae (all claimed). The method is useful to produce bio-fertilizers, cattle waste stock, meat and dairy products.    ADVANTAGE - The method is cost effective and produces the bio-fuel that are also generally sustainable, renewable, and environmentally friendly.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) method comprising: steps (a) and (b) as above per se; anaerobically digesting the manure waste stock to produce a bio-gas, thus a bio-gas byproduct remains after the production of the bio-gas; step (c) as above per se; contacting the exhaust gases produced by the gas turbine with the bio-gas byproduct to produce a fertilizer; and contacting the exhaust gases produced by the gas turbine with the residual source waste stock remaining after the production of the biofuel to produce animal feedstock; and    (2) a system comprising: a bio-fuel production facility configured to produce a bio-fuel from a first source, leaving a residual source waste stock as a byproduct of the bio-fuel production; an animal feedlot including animal manure waste stock; an anaerobic digester configured to digest at least a portion of the manure waste stock from the animal feedlot to produce a bio-gas and a bio-gas byproduct; and at least one gas turbine configured to produce exhaust gases to be contacted with any of the residual source waste stock, where the bio-gas byproduct, or at least a portion of the manure waste stock to produce a converted material.