The hydrogen-oxygen project in the sewage treatment plant at Barth represents an attempt to give an example of the infrastructure which has to be developed for energy hydrogen usage. Hydrogen and oxygen are manufactured and used at one place. There is an option to supply regenerative energy. The emission reduction comes in the sensitive area of the national park region "Vorpommersche Boddenlandschaft". (c) 2004 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.