Book excerpt: This unique compendium emphasizes key factors driving the performance of thermoelectric energy conversion systems. Important design parameters such as heat transfer at the boundaries of the system, material properties, and form factors are carefully analyzed and optimized for performance including the cost-performance trade-off. Numbers of examples are provided on the applications of thermoelectric technologies, e.g., power generation, cooling of electronic components, and waste heat recovery in wearable devices.This must-have volume also includes an interactive modeling software package developed on the nanoHUB (https://nanohub.org/) platform. Professionals, researchers, academics, undergraduate and graduate students will be able to study the impact of material properties and key design parameters on the overall thermoelectric system performance as well as the large scale implementation in the society.