Principles of Sustainable Energy Systems provides students with a fundamental and practical understanding of the energy transition. It discusses the design, production, and economics of energy conversion and storage technologies, as well as requirements and technologies for the end-use sectors of transportation, buildings, and industry. This book begins by introducing students to the important field of sustainability and then presents comprehensive coverage of solar, wind, hydropower, biomass and bio-fuels, geothermal, nuclear, and ocean-based energy technologies. This new edition features recent advances in batteries and other storage technologies, electricity transmission, electric vehicles, and beneficial electrification and demand response in buildings, as well as approaches for reducing emissions from shipping and aviation. It introduces new material on low-carbon building materials, heat pumps, and the practical design aspects of solar photovoltaic systems. This book also covers economics and energy systems analysis methods such as life cycle assessment and greenhouse gas accounting, including detailed examples of design and financial analysis using the System Advisor Model (SAM). This book is intended for upper-level undergraduate and graduate engineering students taking courses in Renewable Energy, Energy Systems, and Energy Conversion. Instructors will have access to a Solutions Manual and Figure Slides for their course.