Researchers from the Bioelectrochemistry group of the Universitat Autònoma de Barcelona (UAB) Department of Chemical Engineering have improved the energetic efficiency of the cells. The experimental results were very positive and demonstrated that these systems would have a market niche at industrial scale. The scientists, coordinated by professors Albert Guisasola and Juan Antonio Baeza, used real wastewater instead of the biodegradable synthetic water used in most experiments, and achieved a biological production of hydrogen and, to a large extent, the recovery of a good part of the energy contained in the residues. To achieve this, researchers selected a set of bacteria capable of transforming complex substrates such as methanol, dairy waste, starch and glycerol, into simpler compounds which could, in turn, be degraded by exoelectrogens.