Front cover: The cover picture reflects the topics of the articles on pp. 150–161 and 183–188: Stratospheric Ozone Depletion and Photovoltaic Systems as Part of the Environment. Cover idea: David Hunkeler (david.hunkeler@aquaplustech.ch). Cover design: Edwin Grondinger, abavo GmbH, Nebelhornstraße 8, 86807 Buchloe, Germany (edwin.grondinger@abavo.de; http://www.abavo.de)