Book excerpt: Complementarity of Variable Renewable Energy Sources consolidates current developments on the subject, addressing all technical advances, presenting new mapping results, and bringing new insights for the continuation of research and implementation on this fascinating topic. By answering questions such as How can complementarity be used in the operation of large interconnected systems?, What is the real applicability potential of energetic complementarity?, and How will it impact energy generation systems?, this title is useful for all researchers, academic and students investigating the topic of renewable energy complementarity in systems. In just over a decade, the subject of 'energy complementarity' has experienced a growing presence and understanding by researchers and managers of energy resources looking to enhance energy systems. Early research proposed methods to quantify complementarity, the effects of complementarity on performance of hybrid systems, and how to identify and map complementarity between solar energy, wind energy and hydroelectric energy systems. - Includes chapter maps to visualize system performance under different complementarity indexes - Addresses complementarity in the operation of large and small to medium-sized hybrid systems - Provides methods for determining complementarity between various energy sources