Prototype Energy Bags (IMAGE) University of Nottingham Caption Small prototypes of the proposed energy bags are tested. Credit The University of Nottingham Usage Restrictions Please credit The University of Nottingham. Only approved for use with this story. License Licensed 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.