GREENS (2 of 2) (image) Office of Naval Research Caption The Ground Renewable Expeditionary ENergy System (GREENS) was developed to provide Marines with continuous power in the field. The 300-watt hybrid battery system uses the sun to generate power. The system is currently in production with several units already in the field. Credit U.S. Navy photo by John F. Williams Usage Restrictions None 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.