Biogas production and utilization with polymer electrolyte membrane (PEM) fuel cells provides a clean and reliable option for decentralized energy supply. The investigative experiments confirmed the fundamental suitability of co-generation from biogas with a modified fuel cell system for residential energy supply. Biogas with a methane content of similar to 60% is generated by solid-state fermentation of a mixture of grass silage and cattle manure. Subsequently, the biogas is processed in a steam reformer to produce hydrogen. A hydrogen purity of > 50% is sufficient for an efficient and stable operation of a PEM fuel cell stack. Power generation via biogas and fuel cells from agricultural residues such as wheat straw can provide a constant power of up to 0.5 kW per hectare of acreage.