EROI by calorie (IMAGE) PNAS Nexus Caption 5-year average energy return on energy investment (EROEI) for different product groups in the period 2015–2019. Credit Rasul et al. Usage Restrictions None 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.