<P><B>Abstract</B></P> <P>Anaerobic Digestion of biodegradable substrates could be considered a promising process in terms of both bio-fuels and bio-products production. In this respect, biohydrogen production during the acidogenic phase and polyhydroxyalkanoate generation through the metabolites circulation, can be considered the new borders of process optimization. The results of the assessment presented in this work shows that anaerobic co-digestion of sludge and food waste is an effective process to achieve energy self-sufficiency of wastewater treatment plants. Through batch tests it was possible to estimate the production of hydrogen and methane in the specific case of sludge and food waste and calculate the primary energy produced by different users of biogas.</P>