How MEPS work (IMAGE) University of Copenhagen - Faculty of Science Caption How MEPS work. UV light and chlorine gas by electrolysis eradicates methane on site. Credit Matthew Stanley Johnson, Department of Chemistry, University of Copenhagen. Usage Restrictions With credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.